Diff for /loncom/interface/loncoursedata.pm between versions 1.49 and 1.205

version 1.49, 2003/02/20 14:28:25 version 1.205, 2021/03/02 19:51:02
Line 1 Line 1
 # The LearningOnline Network with CAPA  # The LearningOnline Network with CAPA
 # (Publication Handler  
 #  #
 # $Id$  # $Id$
 #  #
Line 26 Line 25
 # http://www.lon-capa.org/  # http://www.lon-capa.org/
 #  #
 ###  ###
   
 =pod  =pod
   
 =head1 NAME  =head1 NAME
   
 loncoursedata  Apache::loncoursedata
   
 =head1 SYNOPSIS  =head1 SYNOPSIS
   
Line 39  Set of functions that download and proce Line 37  Set of functions that download and proce
   
 =head1 PACKAGES USED  =head1 PACKAGES USED
   
  Apache::Constants qw(:common :http)    Apache::lonnet
  Apache::lonnet()    Apache::longroup
  Apache::lonhtmlcommon    Time::HiRes
  HTML::TokeParser    Apache::lonmysql
  GDBM_File    LONCAPA
     Digest::MD5
   
 =cut  =cut
   
 package Apache::loncoursedata;  package Apache::loncoursedata;
   
 use strict;  use strict;
 use Apache::Constants qw(:common :http);  use Apache::lonnet;
 use Apache::lonnet();  use Apache::longroup();
 use Apache::lonhtmlcommon;  use Time::HiRes();
 use HTML::TokeParser;  use Apache::lonmysql();
 use GDBM_File;  use LONCAPA;
   use Digest::MD5();
 =pod  
   =pod 
 =head1 DOWNLOAD INFORMATION  
   =head2 make_into_hash
 This section contains all the functions that get data from other servers   
 and/or itself.  Turn a colon separated string into a hash and return a reference
   to it.  Numbering from 0 even elements are keys and odd elements
   are values e.g. a:b:c:d creates a hash like
     a => b, c =>d
   
 =cut  =cut
   
 # ----- DOWNLOAD INFORMATION -------------------------------------------  sub make_into_hash {
       my $values = shift;
 =pod      my %tmp = map { &unescape($_); } split(':',$values);
       return \%tmp;
   }
   
 =item &DownloadClasslist()  
   
 Collects lastname, generation, middlename, firstname, PID, and section for each  { # Begin scope of table identifiers
 student from their environment database.  The section data is also download, though  
 it is in a rough format, and is processed later.  The list of students is built from  
 collecting a classlist for the course that is to be displayed.  Once the classlist  
 has been downloaded, its date stamp is recorded.  Unless the datestamp for the  
 class database is reset or is modified, this data will not be downloaded again.    
 Also, there was talk about putting the fullname and section  
 and perhaps other pieces of data into the classlist file.  This would  
 reduce the number of different file accesses and reduce the amount of   
 processing on this side.  
   
 =over 4  my $current_course ='';
   my $symb_table;
   my $part_table;
   my $student_table;
   my $groupnames_table;
   my $students_groups_table;
   my $performance_table;
   my $parameters_table;
   my $fulldump_response_table;
   my $fulldump_part_table;
   my $fulldump_timestamp_table;
   my $weight_table;
   
   my @Tables;
   
 Input: $courseID, $lastDownloadTime, $c  
   
 $courseID:  The id of the course  
   
 $lastDownloadTime:  This is the date stamp for when this information was  sub init_dbs {
 last gathered.  If it is set to Not downloaded, it will gather the data      my ($courseid,$drop) = @_;
 again, though it currently does not remove the old data.      &setup_table_names($courseid);
       #
       # Drop any of the existing tables
       if ($drop) {
           foreach my $table (@Tables) {
               &Apache::lonmysql::drop_table($table);
           }
       }
       #
       # Note - changes to this table must be reflected in the code that 
       # stores the data (calls &Apache::lonmysql::store_row with this table
       # id
       my $symb_table_def = {
           id => $symb_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'symb',
                         type => 'MEDIUMTEXT',
                         restrictions => 'NOT NULL'},
                       ],
           'PRIMARY KEY' => ['symb_id'],
       };
       #
       my $part_table_def = {
           id => $part_table,
           permanent => 'no',
           columns => [{ name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'part',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL'},
                       ],
           'PRIMARY KEY' => ['part (100)'],
           'KEY' => [{ columns => ['part_id']},],
       };
       #
       my $student_table_def = {
           id => $student_table,
           permanent => 'no',
           columns => [{ name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'student',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL UNIQUE'},
                       { name => 'section',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL'},
                       { name => 'start',
                         type => 'INT',
                         restrictions => 'NOT NULL'},
                       { name => 'end',
                         type => 'INT',
                         restrictions => 'NOT NULL'},
                       { name => 'classification',
                         type => 'VARCHAR(100) BINARY', },
                       { name => 'updatetime',
                         type => 'INT UNSIGNED'},
                       { name => 'fullupdatetime',
                         type => 'INT UNSIGNED'},
                       ],
           'PRIMARY KEY' => ['student_id'],
           'KEY' => [{ columns => ['student (100)',
                                   'section (100)',
                                   'start',
    'end']},],
       };
       #
       my $groupnames_table_def = {
           id => $groupnames_table,
           permanent => 'no',
           columns => [{ name => 'group_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc => 'yes', },
                       { name => 'groupname',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL UNIQUE'},
                      ],
           'PRIMARY KEY' => ['group_id'],
           'KEY' => [{ columns => ['groupname (100)',]},],
       };
       #
       my $students_groups_table_def = {
           id => $students_groups_table,
           permanent => 'no',
           columns => [{ name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL', },
                       { name => 'group_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL', },
                      ],
           'PRIMARY KEY' => ['student_id','group_id'],
           'KEY' => [{ columns => ['student_id'] },
                     { columns => ['group_id'] },],
       };
       #
       my $performance_table_def = {
           id => $performance_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'part',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL'},                    
                       { name => 'solved',
                         type => 'TINYTEXT' },
                       { name => 'tries',
                         type => 'SMALLINT UNSIGNED' },
                       { name => 'awarded',
                         type => 'REAL' },
                       { name => 'award',
                         type => 'TINYTEXT' },
                       { name => 'awarddetail',
                         type => 'TINYTEXT' },
                       { name => 'timestamp',
                         type => 'INT UNSIGNED'},
                       ],
           'PRIMARY KEY' => ['symb_id','student_id','part_id'],
           'KEY' => [{ columns=>['student_id'] },
                     { columns=>['symb_id'] },],
       };
       #
       my $fulldump_part_table_def = {
           id => $fulldump_part_table,
           permanent => 'no',
           columns => [
                       { name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'transaction',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'tries',
                         type => 'SMALLINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'award',
                         type => 'TINYTEXT' },
                       { name => 'awarded',
                         type => 'REAL' },
                       { name => 'previous',
                         type => 'SMALLINT UNSIGNED' },
   #                    { name => 'regrader',
   #                      type => 'TINYTEXT' },
   #                    { name => 'afterduedate',
   #                      type => 'TINYTEXT' },
                       ],
           'PRIMARY KEY' => ['symb_id','part_id','student_id','transaction'],
           'KEY' => [
                     { columns=>['symb_id'] },
                     { columns=>['part_id'] },
                     { columns=>['student_id'] },
                     ],
       };
       #
       my $fulldump_response_table_def = {
           id => $fulldump_response_table,
           permanent => 'no',
           columns => [
                       { name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'response_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'transaction',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'awarddetail',
                         type => 'TINYTEXT' },
   #                    { name => 'message',
   #                      type => 'CHAR BINARY'},
                       { name => 'response_specific',
                         type => 'TINYTEXT' },
                       { name => 'response_specific_value',
                         type => 'TINYTEXT' },
                       { name => 'response_specific_2',
                         type => 'TINYTEXT' },
                       { name => 'response_specific_value_2',
                         type => 'TINYTEXT' },
                       { name => 'submission',
                         type => 'TEXT'},
                       ],
               'PRIMARY KEY' => ['symb_id','part_id','response_id','student_id',
                                 'transaction'],
               'KEY' => [
                         { columns=>['symb_id'] },
                         { columns=>['part_id','response_id'] },
                         { columns=>['student_id'] },
                         ],
       };
       my $fulldump_timestamp_table_def = {
           id => $fulldump_timestamp_table,
           permanent => 'no',
           columns => [
                       { name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'transaction',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'timestamp',
                         type => 'INT UNSIGNED'},
                       ],
           'PRIMARY KEY' => ['symb_id','student_id','transaction'],
           'KEY' => [
                     { columns=>['symb_id'] },
                     { columns=>['student_id'] },
                     { columns=>['transaction'] },
                     ],
       };
       #
       my $parameters_table_def = {
           id => $parameters_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'parameter',
                         type => 'TINYTEXT',
                         restrictions => 'NOT NULL'  },
                       { name => 'value',
                         type => 'MEDIUMTEXT' },
                       ],
           'PRIMARY KEY' => ['symb_id','student_id','parameter (255)'],
       };
       #
       my $weight_table_def = {
           id => $weight_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'weight',
                         type => 'REAL',
                         restrictions => 'NOT NULL'  },
                       ],
           'PRIMARY KEY' => ['symb_id','part_id'],
       };
       #
       # Create the tables
       my $tableid;
       $tableid = &Apache::lonmysql::create_table($symb_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating symb_table: ".
                                    &Apache::lonmysql::get_error());
           return 1;
       }
       #
       $tableid = &Apache::lonmysql::create_table($part_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating part_table: ".
                                    &Apache::lonmysql::get_error());
           return 2;
       }
       #
       $tableid = &Apache::lonmysql::create_table($student_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating student_table: ".
                                    &Apache::lonmysql::get_error());
           return 3;
       }
       #
       $tableid = &Apache::lonmysql::create_table($performance_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating preformance_table: ".
                                    &Apache::lonmysql::get_error());
           return 5;
       }
       #
       $tableid = &Apache::lonmysql::create_table($parameters_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating parameters_table: ".
                                    &Apache::lonmysql::get_error());
           return 6;
       }
       #
       $tableid = &Apache::lonmysql::create_table($fulldump_part_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating fulldump_part_table: ".
                                    &Apache::lonmysql::get_error());
           return 7;
       }
       #
       $tableid = &Apache::lonmysql::create_table($fulldump_response_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating fulldump_response_table: ".
                                    &Apache::lonmysql::get_error());
           return 8;
       }
       $tableid = &Apache::lonmysql::create_table($fulldump_timestamp_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating fulldump_timestamp_table: ".
                                    &Apache::lonmysql::get_error());
           return 9;
       }
       $tableid = &Apache::lonmysql::create_table($weight_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating weight_table: ".
                                    &Apache::lonmysql::get_error());
           return 10;
       }
       $tableid = &Apache::lonmysql::create_table($groupnames_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating groupnames_table: ".
                                    &Apache::lonmysql::get_error());
           return 11;
       }
       $tableid = &Apache::lonmysql::create_table($students_groups_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating student_groups_table: ".
                                    &Apache::lonmysql::get_error());
           return 12;
       }
       return 0;
   }
   
 $c: The connection class that can determine if the browser has aborted.  It  =pod
 is used to short circuit this function so that it does not continue to   
 get information when there is no need.  
   
 Output: \%classlist  =head2 delete_caches
   
 \%classlist: A pointer to a hash containing the following data:  Drops all of the tables in the local mysql cache associated with the
   specified course id.
   
 -A list of student name:domain (as keys) (known below as $name)  TODO:  The drops should be pushed into lonmysql to further isolate 
   mysql code from other modules.
   
 -A hash pointer for each student containing lastname, generation, firstname,  =cut
 middlename, and PID : Key is $name.studentInformation  sub delete_caches {
       my $courseid = shift;
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       foreach my $table (@Tables) {
           my $command = 'DROP TABLE '.$table.';';
           $dbh->do($command);
           if ($dbh->err) {
               &Apache::lonnet::logthis($command.' resulted in error: '.$dbh->errstr);
           }
       }
       return;
   }
   
 -A hash pointer to each students section data : Key is $name.section  
   
 -If there was an error in dump, it will be returned in the hash.  See  my $have_read_part_table = 0;
 the error codes for dump in lonnet.  Also, an error key will be   my %ids_by_part;
 generated if an abort occurs.  my %parts_by_id;
   
   sub get_part_id {
       my ($part) = @_;
       $part = 0 if (! defined($part));
       if (! $have_read_part_table) {
           my @Result = &Apache::lonmysql::get_rows($part_table);
           foreach (@Result) {
               $ids_by_part{$_->[1]}=$_->[0];
           }
           $have_read_part_table = 1;
       }
       if (! exists($ids_by_part{$part})) {
           &Apache::lonmysql::store_row($part_table,[undef,$part]);
           undef(%ids_by_part);
           my @Result = &Apache::lonmysql::get_rows($part_table);
           foreach (@Result) {
               $ids_by_part{$_->[1]}=$_->[0];
           }
       }
       return $ids_by_part{$part} if (exists($ids_by_part{$part}));
       return undef; # error
   }
   
 =back  sub get_part {
       my ($part_id) = @_;
       if (! exists($parts_by_id{$part_id})  || 
           ! defined($parts_by_id{$part_id}) ||
           $parts_by_id{$part_id} eq '') {
           my @Result = &Apache::lonmysql::get_rows($part_table);
           foreach (@Result) {
               $parts_by_id{$_->[0]}=$_->[1];
           }
       }
       return $parts_by_id{$part_id} if(exists($parts_by_id{$part_id}));
       return undef; # error
   }
   
 =cut  
   
 sub DownloadClasslist {  my $have_read_symb_table = 0;
     my ($courseID, $lastDownloadTime, $c)=@_;  my %ids_by_symb;
     my ($courseDomain,$courseNumber)=split(/\_/,$courseID);  my %symbs_by_id;
     my %classlist;  
   sub get_symb_id {
     my $modifiedTime = &Apache::lonnet::GetFileTimestamp($courseDomain, $courseNumber,      my ($symb) = @_;
                                                          'classlist.db',       if (! $have_read_symb_table) {
                                                          $Apache::lonnet::perlvar{'lonUsersDir'});          my @Result = &Apache::lonmysql::get_rows($symb_table);
           foreach (@Result) {
     # Always download the information if lastDownloadTime is set to              $ids_by_symb{$_->[1]}=$_->[0];
     # Not downloaded, otherwise it is only downloaded if the file          }
     # has been updated and has a more recent date stamp          $have_read_symb_table = 1;
     if($lastDownloadTime ne 'Not downloaded' &&      }
        $lastDownloadTime >= $modifiedTime && $modifiedTime >= 0) {      if (! exists($ids_by_symb{$symb})) {
         # Data is not gathered so return UpToDate as true.  This          &Apache::lonmysql::store_row($symb_table,[undef,$symb]);
         # will be interpreted in ProcessClasslist          undef(%ids_by_symb);
         $classlist{'lastDownloadTime'}=time;          my @Result = &Apache::lonmysql::get_rows($symb_table);
         $classlist{'UpToDate'} = 'true';          foreach (@Result) {
         return \%classlist;              $ids_by_symb{$_->[1]}=$_->[0];
           }
     }      }
       return $ids_by_symb{$symb} if(exists( $ids_by_symb{$symb}));
       return undef; # error
   }
   
     %classlist=&Apache::lonnet::dump('classlist',$courseDomain, $courseNumber);  sub get_symb {
     foreach(keys (%classlist)) {      my ($symb_id) = @_;
         if(/^(con_lost|error|no_such_host)/i) {      if (! exists($symbs_by_id{$symb_id})  || 
     return;          ! defined($symbs_by_id{$symb_id}) ||
           $symbs_by_id{$symb_id} eq '') {
           my @Result = &Apache::lonmysql::get_rows($symb_table);
           foreach (@Result) {
               $symbs_by_id{$_->[0]}=$_->[1];
         }          }
     }      }
       return $symbs_by_id{$symb_id} if(exists( $symbs_by_id{$symb_id}));
       return undef; # error
   }
   
     foreach my $name (keys(%classlist)) {  my $have_read_student_table = 0;
         if(defined($c) && ($c->aborted())) {  my %ids_by_student;
             $classlist{'error'}='aborted';  my %students_by_id;
             return \%classlist;  
   sub get_student_id {
       my ($sname,$sdom) = @_;
       my $student = $sname.':'.$sdom;
       if (! $have_read_student_table) {
           my @Result = &Apache::lonmysql::get_rows($student_table);
           foreach (@Result) {
               $ids_by_student{$_->[1]}=$_->[0];
           }
           $have_read_student_table = 1;
       }
       if (! exists($ids_by_student{$student})) {
           &populate_student_table();
           undef(%ids_by_student);
           undef(%students_by_id);
           my @Result = &Apache::lonmysql::get_rows($student_table);
           foreach (@Result) {
               $ids_by_student{$_->[1]}=$_->[0];
         }          }
       }
       return $ids_by_student{$student} if(exists( $ids_by_student{$student}));
       return undef; # error
   }
   
         my ($studentName,$studentDomain) = split(/\:/,$name);  sub get_student {
         # Download student environment data, specifically the full name and id.      my ($student_id) = @_;
         my %studentInformation=&Apache::lonnet::get('environment',      if (! exists($students_by_id{$student_id})  || 
                                                     ['lastname','generation',          ! defined($students_by_id{$student_id}) ||
                                                      'firstname','middlename',          $students_by_id{$student_id} eq '') {
                                                      'id'],          my @Result = &Apache::lonmysql::get_rows($student_table);
                                                     $studentDomain,          foreach (@Result) {
                                                     $studentName);              $students_by_id{$_->[0]}=$_->[1];
         $classlist{$name.':studentInformation'}=\%studentInformation;  
   
         if($c->aborted()) {  
             $classlist{'error'}='aborted';  
             return \%classlist;  
         }          }
       }
       return $students_by_id{$student_id} if(exists($students_by_id{$student_id}));
       return undef; # error
   }
   
         #Section  sub populate_student_table {
         my %section=&Apache::lonnet::dump('roles',$studentDomain,$studentName);      my ($courseid) = @_;
         $classlist{$name.':sections'}=\%section;      if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       &setup_table_names($courseid);
       &init_dbs($courseid,0);
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = 'INSERT IGNORE INTO '.$student_table.
           "(student,section,start,end) VALUES ";
       my $cdom = $env{'course.'.$courseid.'.domain'};
       my $cnum = $env{'course.'.$courseid.'.num'};
       my $classlist = &get_classlist($cdom,$cnum);
       my $student_count=0;
       while (my ($student,$data) = each %$classlist) {
           my ($section,$start,$end) = ($data->[&CL_SECTION()],
        $data->[&CL_START()],
        $data->[&CL_END()]);
           if ($section eq '' || $section =~ /^\s*$/) {
               $section = 'none';
           }
    if (!defined($start)) { $start = 0; }
    if (!defined($end))   { $end   = 0; }
           $request .= "('".$student."','".$section."','".$start."','".$end."'),";
           $student_count++;
       }
       return if ($student_count == 0);
       chop($request);
       $dbh->do($request);
       if ($dbh->err()) {
           &Apache::lonnet::logthis("error ".$dbh->errstr().
                                    " occurred executing \n".
                                    $request);
     }      }
       return;
   }
   
     $classlist{'UpToDate'} = 'false';  my $have_read_groupnames_table = 0;
     $classlist{'lastDownloadTime'}=time;  my %ids_by_groupname;
   
     return \%classlist;  sub get_group_id {
       my ($groupname) = @_;
       if (! $have_read_groupnames_table) {
           my @Result = &Apache::lonmysql::get_rows($groupnames_table);
           foreach (@Result) {
               $ids_by_groupname{$_->[1]}=$_->[0];
           }
           $have_read_groupnames_table = 1;
       }
       if (! exists($ids_by_groupname{$groupname})) {
           &populate_groupnames_table();
           undef(%ids_by_groupname);
           my @Result = &Apache::lonmysql::get_rows($groupnames_table);
           foreach (@Result) {
               $ids_by_groupname{$_->[1]}=$_->[0];
           }
       }
       if (exists($ids_by_groupname{$groupname})) {
           return $ids_by_groupname{$groupname};
       }
       return undef; # error
 }  }
   
 =pod  sub populate_groupnames_table {
       my ($courseid) = @_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       &setup_table_names($courseid);
       &init_dbs($courseid,0);
       my $dbh = &Apache::lonmysql::get_dbh();
       my $cdom = $env{'course.'.$courseid.'.domain'};
       my $cnum = $env{'course.'.$courseid.'.num'};
       my %curr_groups = &Apache::longroup::coursegroups($cdom,$cnum);
       return if (!%curr_groups);
       my $request = 'INSERT IGNORE INTO '.$groupnames_table.
                     '(groupname) VALUES ';
       foreach my $groupname (sort(keys(%curr_groups)),'none') {
           $request .= "('".$groupname."'),";
       }
       chop($request);
       $dbh->do($request);
       if ($dbh->err()) {
           &Apache::lonnet::logthis("error ".$dbh->errstr().
                                    " occurred executing \n".
                                    $request);
       }
       return;
   }
   
 =item &DownloadCourseInformation()  my $have_read_studentsgroups_table = 0;
   my %groupids_by_studentid;
   
 Dump of all the course information for a single student.  The data can be  sub get_students_groupids {
 pruned by making use of dumps regular expression arguement.  This function      my ($student_id) = @_;
 also takes a regular expression which it passes straight through to dump.        if (! $have_read_studentsgroups_table) {
 The data is no escaped, because it is done elsewhere.  It also          my @Result = &Apache::lonmysql::get_rows($students_groups_table);
 checks the timestamp of the students course database file and only downloads          foreach (@Result) {
 if it has been modified since the last download.              push(@{$groupids_by_studentid{$_->[0]}},$_->[1]);
           }
           $have_read_studentsgroups_table = 1;
       }
       if (! exists($groupids_by_studentid{$student_id})) {
           &populate_students_groups_table();
           undef(%groupids_by_studentid);
           my @Result = &Apache::lonmysql::get_rows($students_groups_table);
           foreach (@Result) {
               push(@{$groupids_by_studentid{$_->[0]}},$_->[1]);
           }
       }
       if (exists($groupids_by_studentid{$student_id})) {
           if (ref($groupids_by_studentid{$student_id}) eq 'ARRAY') {
               return @{$groupids_by_studentid{$student_id}};
           }
       }
       return undef; # error
   }
   
 =over 4  
   
 Input: $namedata, $courseID, $lastDownloadTime, $WhatIWant  sub populate_students_groups_table {
       my ($courseid) = @_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       &setup_table_names($courseid);
       &init_dbs($courseid,0);
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = 'INSERT IGNORE INTO '.$students_groups_table.
           "(student_id,group_id) VALUES ";
       my $cdom = $env{'course.'.$courseid.'.domain'};
       my $cnum = $env{'course.'.$courseid.'.num'};
       my ($classlist,$keylist) = &get_classlist($cdom,$cnum);
       my ($classgroups,$studentgroups) = &get_group_memberships($classlist,
                                                                 $keylist,
                                                                 $cdom,$cnum);
       my $record_count = 0;
       foreach my $student (sort(keys(%{$classgroups}))) {
           my $student_id = &get_student_id(split(':',$student));
           my @studentsgroups = &get_students_groups($student,'Active',$classgroups);
           if (@studentsgroups < 1) {
               @studentsgroups = ('none');
           }
           foreach my $groupname (@studentsgroups) {
               my $group_id = &get_group_id($groupname);
               $request .= "('".$student_id."','".$group_id."'),";
               $record_count++;
           }
       }
       return if ($record_count == 0);
       chop($request);
       $dbh->do($request);
       if ($dbh->err()) {
           &Apache::lonnet::logthis("error ".$dbh->errstr().
                                    " occurred executing \n".
                                    $request);
       }
       return;
   }
   
 $namedata: student name:domain  sub clear_internal_caches {
       $have_read_part_table = 0;
       undef(%ids_by_part);
       undef(%parts_by_id);
       $have_read_symb_table = 0;
       undef(%ids_by_symb);
       undef(%symbs_by_id);
       $have_read_student_table = 0;
       undef(%ids_by_student);
       undef(%students_by_id);
       $have_read_groupnames_table = 0;
       undef(%ids_by_groupname);
   }
   
 $courseID:  The id of the course  sub symb_is_for_task {
       my ($symb) = @_;
       return ($symb =~ /\.task$/);
   }
   
 $lastDownloadTime:  This is the date stamp for when this information was  
 last gathered.  If it is set to Not downloaded, it will gather the data  
 again, though it currently does not remove the old data.  
   
 $WhatIWant:  Regular expression used to get selected data with dump  sub update_full_student_data {
       my ($sname,$sdom,$courseid) = @_;
       #
       # Set up database names
       &setup_table_names($courseid);
       #
       my $student_id = &get_student_id($sname,$sdom);
       my $student = $sname.':'.$sdom;
       #
       my $returnstatus = 'okay';
       #
       # Download students data
       my $time_of_retrieval = time;
       my @tmp = &Apache::lonnet::dumpstore($courseid,$sdom,$sname);
       if (@tmp && $tmp[0] =~ /^error/) {
           $returnstatus = 'error retrieving full student data';
           return $returnstatus;
       } elsif (! @tmp) {
           $returnstatus = 'okay: no student data';
           return $returnstatus;
       }
       my %studentdata = @tmp;
       #
       # Get database handle and clean out the tables 
       my $dbh = &Apache::lonmysql::get_dbh();
       $dbh->do('DELETE FROM '.$fulldump_response_table.' WHERE student_id='.
                $student_id);
       $dbh->do('DELETE FROM '.$fulldump_part_table.' WHERE student_id='.
                $student_id);
       $dbh->do('DELETE FROM '.$fulldump_timestamp_table.' WHERE student_id='.
                $student_id);
       #
       # Parse and store the data into a form we can handle
       my $partdata;
       my $respdata;
       while (my ($key,$value) = each(%studentdata)) {
           next if ($key =~ /^(\d+):(resource$|subnum$|keys:)/);
           my ($transaction,$symb,$parameter) = split(':',$key);
    $symb = &unescape($symb);
    $parameter = &unescape($parameter);
           my $symb_id = &get_symb_id($symb);
           if ($parameter eq 'timestamp') {
               # We can deal with 'timestamp' right away
               my @timestamp_storage = ($symb_id,$student_id,
                                        $transaction,$value);
               my $store_command = 'INSERT IGNORE INTO '.$fulldump_timestamp_table.
                   " VALUES ('".join("','",@timestamp_storage)."');";
               $dbh->do($store_command);
               if ($dbh->err()) {
                   &Apache::lonnet::logthis('unable to execute '.$store_command);
                   &Apache::lonnet::logthis($dbh->errstr());
               }
               next;
           } elsif ($parameter eq 'version') {
               next;
    } elsif (&symb_is_for_task($symb)) {
       next if ($parameter !~ /^resource\.(.*)\.(award|
         awarded|
         solved|
         submission|
         portfiles|
         status|
         version|
         regrader)\s*$/x);
       my ($version_and_part_id, $field) = ($1,$2);
   
       next if ($version_and_part_id !~ /\./ 
        && $field ne 'regrader' && $field ne 'version');
   
       my ($version, $part, $instance) = 
    split(/\./,$version_and_part_id);
   
       #skip and instance dimension or criteria specific data
       next if (defined($instance) 
        && $instance ne $field
        && $instance ne 'bridgetask');
       
       if (!defined($part)) {
    $part = $version;
       }
       my $resp_id = &get_part_id('0');
       my $part_id = &get_part_id($part);
       
       if ($field eq 'version') {
    # for tasks each version is an attempt at it thus
    #     version -> tries
    $partdata->{$symb_id}{$part_id}{$transaction}{'tries'}=
       $value;
    # at new version time the record gets reset thus adding a
    # virtual response awarddetail of 'new_version'
    $respdata->{$symb_id}{$part_id}{$resp_id}{$transaction}{'response_specific'}='status';
    $respdata->{$symb_id}{$part_id}{$resp_id}{$transaction}{'response_specific_value'}='new_version';
   
       } elsif ($field eq 'award' || $field eq 'awarded' 
        || $field eq 'solved') {
    $partdata->{$symb_id}{$part_id}{$transaction}{$field}=
       $value;
       } elsif ($field eq 'portfiles') {
    # tasks only accepts portfolio submissions
    $value = $dbh->quote($value);
    $respdata->{$symb_id}{$part_id}{$resp_id}{$transaction}{'submission'}=$value;
       } elsif ($field eq 'status') {
    $respdata->{$symb_id}{$part_id}{$resp_id}{$transaction}{'response_specific'}=$field;
    $respdata->{$symb_id}{$part_id}{$resp_id}{$transaction}{'response_specific_value'}=$value;
       } elsif ($field eq 'regrader') {
    $respdata->{$symb_id}{$part_id}{$resp_id}{$transaction}{'response_specific_2'}=$field;
    $respdata->{$symb_id}{$part_id}{$resp_id}{$transaction}{'response_specific_value_2'}=$value;
       }
    } elsif ($parameter =~ /^resource\.(.*)\.(tries|
                                                     award|
                                                     awarded|
                                                     previous|
                                                     solved|
                                                     awarddetail|
                                                     submission|
                                                     submissiongrading|
                                                     molecule)\s*$/x){
               # we do not have enough information to store an 
               # entire row, so we save it up until later.
               my ($part_and_resp_id,$field) = ($1,$2);
               my ($part,$part_id,$resp,$resp_id);
               if ($part_and_resp_id =~ /\./) {
                   ($part,$resp) = split(/\./,$part_and_resp_id);
                   $part_id = &get_part_id($part);
                   $resp_id = &get_part_id($resp);
               } else {
                   $part_id = &get_part_id($part_and_resp_id);
               }
               # Deal with part specific data
               if ($field =~ /^(tries|award|awarded|previous)$/) {
                   $partdata->{$symb_id}->{$part_id}->{$transaction}->{$field}=$value;
               }
               # deal with response specific data
               if (defined($resp_id) &&
                   $field =~ /^(awarddetail|
                                submission|
                                submissiongrading|
                                molecule)$/x) {
                   if ($field eq 'submission') {
                       # We have to be careful with user supplied input.
                       # most of the time we are okay because it is escaped.
                       # However, there is one wrinkle: submissions which end in
                       # and odd number of '\' cause insert errors to occur.  
                       # Best trap this somehow...
                       $value = $dbh->quote($value);
                   }
                   if ($field eq 'submissiongrading' || 
                       $field eq 'molecule') {
                       $respdata->{$symb_id}->{$part_id}->{$resp_id}->{$transaction}->{'response_specific'}=$field;
                       $respdata->{$symb_id}->{$part_id}->{$resp_id}->{$transaction}->{'response_specific_value'}=$value;
                   } else {
                       $respdata->{$symb_id}->{$part_id}->{$resp_id}->{$transaction}->{$field}=$value;
                   }
               }
           }
       }
       ##
       ## Store the part data
       my $store_command = 'INSERT IGNORE INTO '.$fulldump_part_table.
           ' VALUES '."\n";
       my $store_rows = 0;
       while (my ($symb_id,$hash1) = each (%$partdata)) {
           while (my ($part_id,$hash2) = each (%$hash1)) {
               while (my ($transaction,$data) = each (%$hash2)) {
                   $store_command .= "('".join("','",$symb_id,$part_id,
                                               $student_id,
                                               $transaction,
                                               $data->{'tries'},
                                               $data->{'award'},
                                               $data->{'awarded'},
                                               $data->{'previous'})."'),";
                   $store_rows++;
               }
           }
       }
       if ($store_rows) {
           chop($store_command);
           $dbh->do($store_command);
           if ($dbh->err) {
               $returnstatus = 'error saving part data';
               &Apache::lonnet::logthis('insert error '.$dbh->errstr());
               &Apache::lonnet::logthis("While attempting\n".$store_command);
           }
       }
       ##
       ## Store the response data
       $store_command = 'INSERT IGNORE INTO '.$fulldump_response_table.
           ' VALUES '."\n";
       $store_rows = 0;
       while (my ($symb_id,$hash1) = each (%$respdata)) {
           while (my ($part_id,$hash2) = each (%$hash1)) {
               while (my ($resp_id,$hash3) = each (%$hash2)) {
                   while (my ($transaction,$data) = each (%$hash3)) {
                       my $submission = $data->{'submission'};
                       # We have to be careful with user supplied input.
                       # most of the time we are okay because it is escaped.
                       # However, there is one wrinkle: submissions which end in
                       # and odd number of '\' cause insert errors to occur.  
                       # Best trap this somehow...
                       $submission = $dbh->quote($submission);
                       $store_command .= "('".
                           join("','",$symb_id,$part_id,
                                $resp_id,$student_id,
                                $transaction,
                                $data->{'awarddetail'},
                                $data->{'response_specific'},
                                $data->{'response_specific_value'},
                                $data->{'response_specific_2'},
                                $data->{'response_specific_value_2'}).
                                "',".$submission."),";
                       $store_rows++;
                   }
               }
           }
       }
       if ($store_rows) {
           chop($store_command);
           $dbh->do($store_command);
           if ($dbh->err) {
               $returnstatus = 'error saving response data';
               &Apache::lonnet::logthis('insert error '.$dbh->errstr());
               &Apache::lonnet::logthis("While attempting\n".$store_command);
           }
       }
       ##
       ## Update the students "current" data in the performance 
       ## and parameters tables.
       my ($status,undef) = &store_student_data
           ($sname,$sdom,$courseid,
            &Apache::lonnet::convert_dump_to_currentdump(\%studentdata));
       if ($returnstatus eq 'okay' && $status ne 'okay') {
           $returnstatus = 'error saving current data:'.$status;
       } elsif ($status ne 'okay') {
           $returnstatus .= ' error saving current data:'.$status;
       }        
       ##
       ## Update the students time......
       if ($returnstatus eq 'okay') {
           &store_updatetime($student_id,$time_of_retrieval,$time_of_retrieval);
           if ($dbh->err) {
               if ($returnstatus eq 'okay') {
                   $returnstatus = 'error updating student time';
               } else {
                   $returnstatus = 'error updating student time';
               }
           }
       }
       return $returnstatus;
   }
   
 Output: \%courseData  
   
 \%courseData:  A hash pointer to the raw data from the students course  sub update_student_data {
 database.      my ($sname,$sdom,$courseid) = @_;
       #
       # Set up database names
       &setup_table_names($courseid);
       #
       my $student_id = &get_student_id($sname,$sdom);
       my $student = $sname.':'.$sdom;
       #
       my $returnstatus = 'okay';
       #
       # Download students data
       my $time_of_retrieval = time;
       my %student_data = &Apache::lonnet::currentdump($courseid,$sdom,$sname);
       if (&Apache::lonnet::error(%student_data)) {
           &Apache::lonnet::logthis('error getting data for '.
                                    $sname.':'.$sdom.' in course '.$courseid.
                                    ':'.(%student_data)[0]);
           $returnstatus =(%student_data)[0] ;
           return ($returnstatus,undef);
       }
       if (scalar(keys(%student_data)) < 1) {
           return ('no data',undef);
       }
       my @Results = &store_student_data($sname,$sdom,$courseid,\%student_data);
       #
       # Set the students update time
       if ($Results[0] eq 'okay') {
           &store_updatetime($student_id,$time_of_retrieval);
       }
       #
       return @Results;
   }
   
 =back  sub store_updatetime {
       my ($student_id,$updatetime,$fullupdatetime)=@_;
       my $values = '';
       if (defined($updatetime)) {
           $values = 'updatetime='.$updatetime.' ';
       }
       if (defined($fullupdatetime)) {
           if ($values ne '') {
               $values .= ',';
           }
           $values .= 'fullupdatetime='.$fullupdatetime.' ';
       }
       return if ($values eq '');
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = 'UPDATE '.$student_table.' SET '.$values.
           ' WHERE student_id='.$student_id.' LIMIT 1';
       $dbh->do($request);
   }
   
 =cut  my $requested_max_packet = 0;
   my $max_allowed_packet;
   
 sub DownloadCourseInformation {  sub store_student_data {
     my ($namedata,$courseID,$lastDownloadTime,$WhatIWant)=@_;      my ($sname,$sdom,$courseid,$student_data) = @_;
     my %courseData;      #
     my ($name,$domain) = split(/\:/,$namedata);      my $student_id = &get_student_id($sname,$sdom);
       my $student = $sname.':'.$sdom;
       #
       my $returnstatus = 'okay';
       #
       # Remove all of the students data from the table
       my $dbh = &Apache::lonmysql::get_dbh();
       $dbh->do('DELETE FROM '.$performance_table.' WHERE student_id='.
                $student_id);
       $dbh->do('DELETE FROM '.$parameters_table.' WHERE student_id='.
                $student_id);
       #
       # Store away the data
       #
       my $starttime = Time::HiRes::time;
       my $elapsed = 0;
       my $rows_stored;
       my $store_parameters_prefix  = 'INSERT IGNORE INTO '.$parameters_table.
           ' VALUES '."\n";
       my $num_parameters = 0;
       my $store_performance_prefix = 'INSERT IGNORE INTO '.$performance_table.
           ' VALUES '."\n";
       return ('error',undef) if (! defined($dbh));
       unless ($requested_max_packet) {
           (undef,$max_allowed_packet) = $dbh->selectrow_array(
                                                qq{show variables LIKE ? },
                                                undef,
                                                "max_allowed_packet");
           if ($max_allowed_packet !~ /^\d+$/) {
               $max_allowed_packet = '';
           }
           $requested_max_packet = 1;
       }
       my @store_parameters_values = ();
       my $curr_params_values = '';
       my $curr_params_length = 0;
       my @store_performance_values = ();
       my $curr_perf_values = '';
       my $curr_perf_length = 0;
       my ($max_param,$max_perf);
       if ($max_allowed_packet) {
           $max_param = $max_allowed_packet - length($store_parameters_prefix);
           $max_perf = $max_allowed_packet - length($store_performance_prefix);
       }
       while (my ($current_symb,$param_hash) = each(%{$student_data})) {
           #
           # make sure the symb is set up properly
           my $symb_id = &get_symb_id($current_symb);
           #
           # Parameters
           while (my ($parameter,$value) = each(%$param_hash)) {
               if ($parameter !~ /(timestamp|resource\.(.*)\.(solved|tries|awarded|award|awarddetail|previous))/) {
                   my $sql_parameter = "('".join("','",
                                                 $symb_id,$student_id,
                                                 $parameter)."',".
                                                     $dbh->quote($value)."),\n";
                   if ($sql_parameter !~ /''/) {
                       if ($max_param) {
                           my $length = length($sql_parameter);
                           if ($length > $max_param) {
                               &Apache::lonnet::logthis("SQL parameter insert for student: $sname for parameter: $parameter would exceed max_allowed_packet size");
                               &Apache::lonnet::logthis("symb_id: $symb_id");
                               &Apache::lonnet::logthis("Skipping this item.  You may want to increase the max_allowed_packet size from the current: $max_allowed_packet");
                               next;
                           } else {
                               if ($length + $curr_params_length > $max_param) {
                                   push(@store_parameters_values,$curr_params_values);
                                   $curr_params_values = $sql_parameter;
                                   $curr_params_length = $length;
                               } else {
                                   $curr_params_values .= $sql_parameter;
                                   $curr_params_length += $length;
                               }
                           }
                       } else {
                           $curr_params_values .= $sql_parameter;
                       }
                       #$rows_stored++;
                       $num_parameters ++;
                   }
               }
           }
           # Performance
           my %stored;
           while (my ($parameter,$value) = each(%$param_hash)) {
               next if ($parameter !~ /^resource\.(.*)\.(solved|awarded)$/);
               my $part  = $1;
       my $which = $2;
       next if ($part =~ /\./);
               next if (exists($stored{$part}));
               $stored{$part}++;
               #
               my $part_id = &get_part_id($part);
               next if (!defined($part_id));
       
               my ($solved,$awarded);
       if ($which eq 'solved') {
    $solved  = $value;
    $awarded = $param_hash->{'resource.'.$part.'.awarded'};
       } else {
    $solved  = $param_hash->{'resource.'.$part.'.solved'};
    $awarded = $value;
       }
               my $award   = $param_hash->{'resource.'.$part.'.award'};
               my $awarddetail = $param_hash->{'resource.'.$part.'.awarddetail'};
               my $timestamp = $param_hash->{'timestamp'};
       my $tries   = $param_hash->{'resource.'.$part.'.tries'};
       if (&symb_is_for_task($current_symb)) {
    $tries   = $param_hash->{'resource.'.$part.'.version'};
       }
               #
               $solved      = '' if (! defined($solved));
               $tries       = '' if (! defined($tries));
               $awarded     = '' if (! defined($awarded));
               $award       = '' if (! defined($award));
               $awarddetail = '' if (! defined($awarddetail));
               my $sql_performance = 
                   "('".join("','",$symb_id,$student_id,$part_id,$part,
                                   $solved,$tries,$awarded,$award,
                                   $awarddetail,$timestamp)."'),\n";
               if ($max_perf) {
                   my $length = length($sql_performance);
                   if ($length > $max_perf) {
                               &Apache::lonnet::logthis("SQL performance insert for student: $sname would exceed max_allowed_packet size");
                               &Apache::lonnet::logthis("symb_id: $symb_id");
                               &Apache::lonnet::logthis("Skipping this item.  You may want to increase the max_allowed_packet size from the current: $max_allowed_packet");
                               next;
                   } else {
                       if ($length + $curr_perf_length > $max_perf) {
                           push(@store_performance_values,$curr_perf_values);
                           $curr_perf_values = $sql_performance;
                           $curr_perf_length = $length;
                       } else {
                           $curr_perf_values .= $sql_performance;
                           $curr_perf_length += $length;
                       }
                   }
               } else {
                   $curr_perf_values .= $sql_performance;
               }
               $rows_stored++;
           }
       }
       if ($curr_params_values ne '') {
           push(@store_parameters_values,$curr_params_values);
       }
       if ($curr_perf_values ne '') {
           push(@store_performance_values,$curr_perf_values);
       }
       if (! $rows_stored) { return ($returnstatus, undef); }
       my $start = Time::HiRes::time;
       foreach my $item (@store_performance_values) {
           $item =~ s|,\n$||;
           if ($item ne '') {
               $dbh->do($store_performance_prefix.$item);
               if ($dbh->err()) {
                   &Apache::lonnet::logthis('performance insert error:'.
                                            $dbh->errstr());
                   &Apache::lonnet::logthis('command = '.$/.$store_performance_prefix.$item);
                   $returnstatus = 'error: unable to insert performance into database';
                   return ($returnstatus,$student_data);
               }
           }
       }
       if ($num_parameters > 0) {
           foreach my $item (@store_parameters_values) {
               $item =~ s|,\n$||;
               if ($item ne '') {
                   $dbh->do($store_parameters_prefix.$item);
                   if ($dbh->err()) {
                        &Apache::lonnet::logthis('parameters insert error:'.
                                                 $dbh->errstr());
                        &Apache::lonnet::logthis('command = '.$/.$store_parameters_prefix.$item);
                        &Apache::lonnet::logthis('rows_stored = '.$rows_stored);
                        &Apache::lonnet::logthis('student_id = '.$student_id);
                        $returnstatus = 'error: unable to insert parameters into database';
                        return ($returnstatus,$student_data);
                   }
               }
           }
       }
       $elapsed += Time::HiRes::time - $start;
       return ($returnstatus,$student_data);
   }
   
     my $modifiedTime = &Apache::lonnet::GetFileTimestamp($domain, $name,  
                                       $courseID.'.db',   
                                       $Apache::lonnet::perlvar{'lonUsersDir'});  
   
     if($lastDownloadTime ne 'Not downloaded' &&   sub ensure_tables_are_set_up {
        $lastDownloadTime >= $modifiedTime && $modifiedTime >= 0) {      my ($courseid) = @_;
         # Data is not gathered so return UpToDate as true.  This      $courseid = $env{'request.course.id'} if (! defined($courseid));
         # will be interpreted in ProcessClasslist      # 
         $courseData{$namedata.':lastDownloadTime'}=time;      # Clean out package variables
         $courseData{$namedata.':UpToDate'} = 'true';      &setup_table_names($courseid);
         return \%courseData;      #
       # if the tables do not exist, make them
       my @CurrentTable = &Apache::lonmysql::tables_in_db();
       my ($found_symb,$found_student,$found_groups,$found_groupnames,$found_part,
           $found_performance,$found_parameters,$found_fulldump_part,
           $found_fulldump_response,$found_fulldump_timestamp,
           $found_weight);
       foreach (@CurrentTable) {
           $found_symb        = 1 if ($_ eq $symb_table);
           $found_student     = 1 if ($_ eq $student_table);
           $found_groups      = 1 if ($_ eq $students_groups_table);
           $found_groupnames  = 1 if ($_ eq $groupnames_table);
           $found_part        = 1 if ($_ eq $part_table);
           $found_performance = 1 if ($_ eq $performance_table);
           $found_parameters  = 1 if ($_ eq $parameters_table);
           $found_fulldump_part      = 1 if ($_ eq $fulldump_part_table);
           $found_fulldump_response  = 1 if ($_ eq $fulldump_response_table);
           $found_fulldump_timestamp = 1 if ($_ eq $fulldump_timestamp_table);
           $found_weight      = 1 if ($_ eq $weight_table);
       }
       if (!$found_symb          || 
           !$found_student       || !$found_part              ||
           !$found_performance   || !$found_parameters        ||
           !$found_fulldump_part || !$found_fulldump_response ||
           !$found_fulldump_timestamp || !$found_weight ) {
           if (&init_dbs($courseid,1)) {
               return 'error';
           }
     }      }
   }
   
     # Download course data  sub ensure_current_data {
     if(!defined($WhatIWant)) {      my ($sname,$sdom,$courseid) = @_;
         # set the regular expression to everything by setting it to period      my $status = 'okay';   # return value
         $WhatIWant = '.';      #
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       &ensure_tables_are_set_up($courseid);
       #
       # Get the update time for the user
       my $updatetime = 0;
       my $getuserdir = 1;
       my $modifiedtime = &Apache::lonnet::GetFileTimestamp
           ($sdom,$sname,$courseid.'.db',$getuserdir);
       #
       if ($modifiedtime == -1) {
    return ('no data',undef);
     }      }
     %courseData=&Apache::lonnet::dump($courseID, $domain, $name, $WhatIWant);  
     $courseData{'UpToDate'} = 'false';  
     $courseData{'lastDownloadTime'}=time;  
   
     my %newData;      my $student_id = &get_student_id($sname,$sdom);
     foreach (keys(%courseData)) {      &get_students_groupids($student_id);
         # need to have the keys to be prepended with the name:domain of the      my @Result = &Apache::lonmysql::get_rows($student_table,
         # student to reduce data collision later.                                               "student_id ='$student_id'");
         $newData{$namedata.':'.$_} = $courseData{$_};      my $data = undef;
       if (@Result) {
           $updatetime = $Result[0]->[6];  # Ack!  This is dumb!
     }      }
       if ($modifiedtime > $updatetime) {
     return \%newData;          ($status,$data) = &update_student_data($sname,$sdom,$courseid);
       }
       return ($status,$data);
 }  }
   
 # ----- END DOWNLOAD INFORMATION ---------------------------------------  
   
 =pod  
   
 =head1 PROCESSING FUNCTIONS  
   
 These functions process all the data for all the students.  Also, they  
 are the functions that access the cache database for writing the majority of  
 the time.  The downloading and caching were separated to reduce problems   
 with stopping downloading then can not tie hash to database later.  
   
 =cut  sub ensure_current_full_data {
       my ($sname,$sdom,$courseid) = @_;
       my $status = 'okay';   # return value
       #
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       &ensure_tables_are_set_up($courseid);
       #
       # Get the update time for the user
       my $getuserdir = 1;
       my $modifiedtime = &Apache::lonnet::GetFileTimestamp
           ($sdom,$sname,$courseid.'.db',$getuserdir);
       #
       my $student_id = &get_student_id($sname,$sdom);
       &get_students_groupids($student_id);
       my @Result = &Apache::lonmysql::get_rows($student_table,
                                                "student_id ='$student_id'");
       my $updatetime;
       if (@Result && ref($Result[0]) eq 'ARRAY') {
           $updatetime = $Result[0]->[7];
       }
       if (! defined($updatetime) || $modifiedtime > $updatetime) {
           $status = &update_full_student_data($sname,$sdom,$courseid);
       }
       return $status;
   }
   
 # ----- PROCESSING FUNCTIONS ---------------------------------------  sub ensure_current_groups {
       my ($courseid) = @_;  
       my ($cdom,$cnum);
       if (defined($courseid)) {
           my %coursehash = &Apache::lonnet::coursedescription($courseid);
           $cdom = $coursehash{'domain'};
           $cnum = $coursehash{'num'};
       } elsif ($env{'request.course.id'}) {
           $courseid = $env{'request.course.id'};
           $cdom = $env{'course.'.$courseid.'.domain'};
           $cnum = $env{'course.'.$courseid.'.num'};
       }
       if ($cdom eq '' || $cnum eq '') {
           return 'error: invalid course';
       }
       &setup_table_names($courseid);
       my @CurrentTables = &Apache::lonmysql::tables_in_db();
       unless (grep(/^\Q$groupnames_table\E$/,@CurrentTables)) {
           return;
       }
       # Get the update time for the groupnames table
       my $getuserdir = 1;
       my $modifiedtime = &Apache::lonnet::GetFileTimestamp
           ($cdom,$cnum,'coursegroups.db',$getuserdir);
       my %tableinfo = &Apache::lonmysql::table_information($groupnames_table);
       my $updatetime;
       if ($tableinfo{'Update_time'}) {
           $updatetime = $tableinfo{'Update_time'};
       }
       if (! defined($updatetime) || $modifiedtime > $updatetime) {
           my (%groups_in_sql,%removegroups,$addgroup);
           my %curr_groups = &Apache::longroup::coursegroups($cdom,$cnum);
           my @Result = &Apache::lonmysql::get_rows($groupnames_table);
           foreach my $row (@Result) {
               my ($id,$name) = @{$row};
               unless (exists($curr_groups{$name})) {
                   $groups_in_sql{$name}=$id;
               } elsif ($id) {
                   $removegroups{$id} = $name;
               }
           }
           foreach my $group (keys(%curr_groups)) {
               unless (exists($groups_in_sql{$group})) {
                   $addgroup = 1;
                   last;
               }
           }
           if (keys(%removegroups)) {
               my $dbh = &Apache::lonmysql::get_dbh();
               foreach my $group_id (keys(%removegroups)) {
                   my $command = 'DELETE FROM '.$groupnames_table.' WHERE group_id='.
                                 $group_id;
                   $dbh->do($command);
                   if ($dbh->err()) {
                       &Apache::lonnet::logthis("error ".$dbh->errstr().
                                                " occurred executing \n".
                                                "SQL command: $command");
                   }
               }
           }
           if ($addgroup) {
               &populate_groupnames_table($courseid);
           }
       }
       return;
   }
   
   sub ensure_current_students_groups {
       my ($courseid) = @_;
       my ($cdom,$cnum);
       if (defined($courseid)) {
           my %coursehash = &Apache::lonnet::coursedescription($courseid);
           $cdom = $coursehash{'domain'};
           $cnum = $coursehash{'num'};
       } elsif ($env{'request.course.id'}) {
           $courseid = $env{'request.course.id'};
           $cdom = $env{'course.'.$courseid.'.domain'};
           $cnum = $env{'course.'.$courseid.'.num'};
       }
       &setup_table_names($courseid);
       my @CurrentTables = &Apache::lonmysql::tables_in_db();
       unless (grep(/^\Q$students_groups_table\E$/,@CurrentTables)) {
           return;
       }
       # Get the update time for the groupnames table
       my $getuserdir = 1;
       my $modifiedtime = &Apache::lonnet::GetFileTimestamp
           ($cdom,$cnum,'groupmembership.db',$getuserdir);
       my %tableinfo = &Apache::lonmysql::table_information($students_groups_table);
       my $updatetime;
       if ($tableinfo{'Update_time'}) {
           $updatetime = $tableinfo{'Update_time'};
       }
       if ((!defined($updatetime)) || ($modifiedtime > $updatetime)) {
           if (&Apache::lonmysql::drop_table($students_groups_table)) {
               if (&init_dbs($courseid)) {
                   return "error creating $students_groups_table\n";
               } else {
                   &populate_students_groups_table($courseid);
               }
           }
       }
       return;
   }
   
   sub ensure_current_sections {
       my ($courseid) = @_;
       my ($cdom,$cnum);
       if (defined($courseid)) {
           my %coursehash = &Apache::lonnet::coursedescription($courseid);
           $cdom = $coursehash{'domain'};
           $cnum = $coursehash{'num'};
       } elsif ($env{'request.course.id'}) {
           $courseid = $env{'request.course.id'};
           $cdom = $env{'course.'.$courseid.'.domain'};
           $cnum = $env{'course.'.$courseid.'.num'};
       }
       &setup_table_names($courseid);
       my @CurrentTables = &Apache::lonmysql::tables_in_db();
       unless (grep(/^\Q$student_table\E$/,@CurrentTables)) {
           return;
       }
       # Get the update time for the student table
       my $getuserdir = 1;
       my $modifiedtime = &Apache::lonnet::GetFileTimestamp
           ($cdom,$cnum,'classlist.db',$getuserdir);
       my %tableinfo = &Apache::lonmysql::table_information($student_table);
       my $updatetime;
       if ($tableinfo{'Update_time'}) {
           $updatetime = $tableinfo{'Update_time'};
       }
       if ((!defined($updatetime)) || ($modifiedtime > $updatetime)) {
           &update_student_table($cdom,$cnum);
       }
       return;
   }
   
 =pod  sub update_student_table {
       my ($cdom,$cnum) = @_;
       return unless (($cdom ne '') && ($cnum ne ''));
       my (%roster,%sqldata);
       my $classlist = &get_classlist($cdom,$cnum);
       while (my ($student,$data) = each (%$classlist)) {
           my ($section,$start,$end) = ($data->[&CL_SECTION()],
                                        $data->[&CL_START()],
                                        $data->[&CL_END()]);
           if ($section eq '' || $section =~ /^\s*$/) {
               $section = 'none';
           }
           if ($start eq '') { $start = 0; }
           if ($end eq '')   { $end   = 0; }
           $roster{$student}{'section'} = $section;
           $roster{$student}{'start'} = $start;
           $roster{$student}{'end'} = $end;
       }
       my $dbh = &Apache::lonmysql::get_dbh();
       my $statement = "SELECT student_id,student,section,start,end FROM $student_table";
       my $sth = $dbh->prepare($statement);
       $sth->execute();
       if ($sth->err()) {
           &Apache::lonnet::logthis("Unable to execute MySQL request:");
           &Apache::lonnet::logthis("\n".$statement."\n");
           &Apache::lonnet::logthis("error is:".$sth->errstr());
           return undef;
       }
       foreach my $row (@{$sth->fetchall_arrayref}) {
           my ($id,$student,$section,$start,$end) = (@$row);
           if (ref($roster{$student}) eq 'HASH') {
               if (($roster{$student}{'section'} ne $section) ||
                   ($roster{$student}{'start'} ne $start) ||
                   ($roster{$student}{'end'} ne $end)) {
                   $sqldata{$id} = {
                                     section => $roster{$student}{'section'},
                                     start   => $roster{$student}{'start'},
                                     end     => $roster{$student}{'end'},
                                   };
               }
           }
       }
       $sth->finish();
       if (keys(%sqldata)) { 
           foreach my $id (sort { $a <=> $b } keys(%sqldata)) {
               my $request = "UPDATE $student_table SET section='$sqldata{$id}{section}'".
                             ", start='$sqldata{$id}{start}'".
                             ", end='$sqldata{$id}{end}' WHERE student_id='$id'";
               $dbh->do($request);
           }
       }
       return;
   }
   
 =item &get_sequence_assessment_data()  sub get_student_data_from_performance_cache {
       my ($sname,$sdom,$symb,$courseid)=@_;
       my $student = $sname.':'.$sdom if (defined($sname) && defined($sdom));
       &setup_table_names($courseid);
       #
       # Return hash
       my $studentdata;
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = "SELECT ".
           "d.symb,a.part,a.solved,a.tries,a.awarded,a.award,a.awarddetail,".
               "a.timestamp ";
       if (defined($student)) {
           $request .= "FROM $student_table AS b ".
               "LEFT JOIN $performance_table AS a ON b.student_id=a.student_id ".
   #            "LEFT JOIN $part_table AS c ON c.part_id = a.part_id ".
               "LEFT JOIN $symb_table AS d ON d.symb_id = a.symb_id ".
                   "WHERE student='$student'";
           if (defined($symb) && $symb ne '') {
               $request .= " AND d.symb=".$dbh->quote($symb);
           }
       } elsif (defined($symb) && $symb ne '') {
           $request .= "FROM $symb_table as d ".
               "LEFT JOIN $performance_table AS a ON d.symb_id=a.symb_id ".
   #            "LEFT JOIN $part_table    AS c ON c.part_id = a.part_id ".
               "LEFT JOIN $student_table AS b ON b.student_id = a.student_id ".
                   "WHERE symb='".$dbh->quote($symb)."'";
       }
       my $starttime = Time::HiRes::time;
       my $rows_retrieved = 0;
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($sth->err()) {
           &Apache::lonnet::logthis("Unable to execute MySQL request:");
           &Apache::lonnet::logthis("\n".$request."\n");
           &Apache::lonnet::logthis("error is:".$sth->errstr());
           return undef;
       }
       foreach my $row (@{$sth->fetchall_arrayref}) {
           $rows_retrieved++;
           my ($symb,$part,$solved,$tries,$awarded,$award,$awarddetail,$time) = 
               (@$row);
           my $base = 'resource.'.$part;
           $studentdata->{$symb}->{$base.'.solved'}  = $solved;
           $studentdata->{$symb}->{$base.'.tries'}   = $tries;
           $studentdata->{$symb}->{$base.'.awarded'} = $awarded;
           $studentdata->{$symb}->{$base.'.award'}   = $award;
           $studentdata->{$symb}->{$base.'.awarddetail'} = $awarddetail;
           $studentdata->{$symb}->{'timestamp'} = $time if (defined($time) && $time ne '');
       }
       ## Get misc parameters
       $request = 'SELECT c.symb,a.parameter,a.value '.
           "FROM $student_table AS b ".
           "LEFT JOIN $parameters_table AS a ON b.student_id=a.student_id ".
           "LEFT JOIN $symb_table AS c ON c.symb_id = a.symb_id ".
           "WHERE student='$student'";
       if (defined($symb) && $symb ne '') {
           $request .= " AND c.symb=".$dbh->quote($symb);
       }
       $sth = $dbh->prepare($request);
       $sth->execute();
       if ($sth->err()) {
           &Apache::lonnet::logthis("Unable to execute MySQL request:");
           &Apache::lonnet::logthis("\n".$request."\n");
           &Apache::lonnet::logthis("error is:".$sth->errstr());
           if (defined($symb) && $symb ne '') {
               $studentdata = $studentdata->{$symb};
           }
           return $studentdata;
       }
       #
       foreach my $row (@{$sth->fetchall_arrayref}) {
           $rows_retrieved++;
           my ($symb,$parameter,$value) = (@$row);
           $studentdata->{$symb}->{$parameter}  = $value;
       }
       #
       if (defined($symb) && $symb ne '') {
           $studentdata = $studentdata->{$symb};
       }
       return $studentdata;
   }
   
 AT THIS TIME THE USE OF THIS FUNCTION IS *NOT* RECOMMENDED  
   
 Use lonnavmaps to build a data structure describing the order and   sub get_current_state {
 assessment contents of each sequence in the current course.      my ($sname,$sdom,$symb,$courseid,$forcedownload)=@_;
       #
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       return () if (! defined($sname) || ! defined($sdom));
       #
       my ($status,$data) = &ensure_current_data($sname,$sdom,$courseid);
   #    &Apache::lonnet::logthis
   #        ('sname = '.$sname.
   #         ' domain = '.$sdom.
   #         ' status = '.$status.
   #         ' data is '.(defined($data)?'defined':'undefined'));
   #    while (my ($symb,$hash) = each(%$data)) {
   #        &Apache::lonnet::logthis($symb."\n----------------------------------");
   #        while (my ($key,$value) = each (%$hash)) {
   #            &Apache::lonnet::logthis("   ".$key." = ".$value);
   #        }
   #    }
       #
       if (defined($data) && defined($symb) && ref($data->{$symb})) {
           return %{$data->{$symb}};
       } elsif (defined($data) && ! defined($symb) && ref($data)) {
           return %$data;
       } 
       if ($status eq 'no data') {
           return ();
       } else {
           if ($status ne 'okay' && $status ne '') {
               &Apache::lonnet::logthis('status = '.$status);
               return ('error: '.$status,undef);
           }
           my $returnhash = &get_student_data_from_performance_cache($sname,$sdom,
                                                         $symb,$courseid);
           return %$returnhash if (defined($returnhash));
       }
       return ();
   }
   
 The returned structure is a hash reference.   
   
 { title  => 'title',  sub get_problem_statistics {
   symb   => 'symb',      my ($Sections,$Groups,$status,$symb,$part,$courseid,$starttime,$endtime) = @_;
   source => '/s/o/u/r/c/e',      return if (! defined($symb) || ! defined($part));
   type  => (container|assessment),      $courseid = $env{'request.course.id'} if (! defined($courseid));
   contents     => [ {},{},{},{} ], # only for container      #
   parts        => [11,13,15],      # only for assessment      &setup_table_names($courseid);
   response_ids => [12,14,16]       # only for assessment      my $symb_id = &get_symb_id($symb);
       my $part_id = &get_part_id($part);
       my $stats_table = &temp_table_name($courseid,'problem_stats');
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       #
       # Clean out the table
       $dbh->do('DROP TABLE '.$stats_table);  # May return an error
       my $request = 
           'CREATE TEMPORARY TABLE '.$stats_table.' '.
           'SELECT a.student_id,a.solved,a.award,a.awarded,a.tries '.
           'FROM '.$performance_table.' AS a ';
       #
       # See if we need to include some requirements on the students
       if ((defined($Sections) && lc($Sections->[0]) ne 'all') || 
           (defined($status)   && lc($status)        ne 'any')) {
           $request .= 'NATURAL LEFT JOIN '.$student_table.' AS b ';
       }
       my ($groups_join,$group_limits) = &limit_by_group($Groups,'b','c','d');
       if (defined($groups_join)) {
           $request .= $groups_join;
       }
       $request .= ' WHERE a.symb_id='.$symb_id.' AND a.part_id='.$part_id;
       #
       # Limit the students included to those specified
       my ($section_limits,$enrollment_limits)=
           &limit_by_section_and_status($Sections,$status,'b');
       #
       # Limit by starttime and endtime
       my $time_requirements = undef;
       if (defined($starttime)) {
           $time_requirements .= 'a.timestamp>='.$starttime;
           if (defined($endtime)) {
               $time_requirements .= ' AND a.timestamp<='.$endtime;
           }
       } elsif (defined($endtime)) {
           $time_requirements .= 'a.timestamp<='.$endtime;
       }
       if (defined($time_requirements)) {
           $request .= ' AND '.$time_requirements;
       }
       if (defined($section_limits)) {
           $request .= ' AND '.$section_limits;
       }
       if (defined($enrollment_limits)) {
           $request .= ' AND '.$enrollment_limits;
       }
       # Limit by group, as required
       if (defined($group_limits)) {
           $request .= ' AND '.$group_limits;
       }
       #
       # Finally, execute the request to create the temporary table
       $dbh->do($request);
       #
       # Collect the first suite of statistics
       $request = 'SELECT COUNT(*),SUM(tries),'.
           'AVG(tries),STD(tries) '.
           'FROM '.$stats_table;
       my ($num,$tries,$mean,$STD) = &execute_SQL_request
           ($dbh,$request);
       #
       $request = 'SELECT MAX(tries),MIN(tries) FROM '.$stats_table.
           ' WHERE awarded>0';
       my ($max,$min) = &execute_SQL_request($dbh,$request);
       #
       $request = 'SELECT SUM(awarded) FROM '.$stats_table;
       my ($Solved) = &execute_SQL_request($dbh,$request);
       #
       $request = 'SELECT SUM(awarded) FROM '.$stats_table.
           " WHERE solved='correct_by_override'";
       my ($solved) = &execute_SQL_request($dbh,$request);
       #
       $Solved -= $solved;
       #
       $num    = 0 if (! defined($num));
       $tries  = 0 if (! defined($tries));
       $max    = 0 if (! defined($max));
       $min    = 0 if (! defined($min));
       $STD    = 0 if (! defined($STD));
       $Solved = 0 if (! defined($Solved) || $Solved < 0);
       $solved = 0 if (! defined($solved));
       #
       # Compute the more complicated statistics
       my $DegOfDiff = 'nan';
       $DegOfDiff = 1-($Solved)/$tries if ($tries>0);
       #
       my $SKEW = 'nan';
       my $wrongpercent = 0;
       my $numwrong = 'nan';
       if ($num > 0) {
           ($SKEW) = &execute_SQL_request($dbh,'SELECT SQRT(SUM('.
                                        'POWER(tries - '.$STD.',3)'.
                                        '))/'.$num.' FROM '.$stats_table);
           $numwrong = $num-$Solved;
           $wrongpercent=int(10*100*$numwrong/$num)/10;
       }
       #
       # Drop the temporary table
       $dbh->do('DROP TABLE '.$stats_table);  # May return an error
       #
       # Return result
       return { num_students => $num,
                tries        => $tries,
                max_tries    => $max,
                min_tries    => $min,
                mean_tries   => $mean,
                std_tries    => $STD,
                skew_tries   => $SKEW,
                num_solved   => $Solved,
                num_override => $solved,
                num_wrong    => $numwrong,
                per_wrong    => $wrongpercent,
                deg_of_diff  => $DegOfDiff };
 }  }
   
 Also returned are array references to the symbs and assessments contained  ##
 in the sequence.  ## This is a helper for get_statistics
   sub execute_SQL_request {
 $hash->{'contents'} is a reference to an array of hashes of the same structure.      my ($dbh,$request)=@_;
   #    &Apache::lonnet::logthis($request);
       my $sth = $dbh->prepare($request);
       if (!$sth) {
    die($dbh->errstr . " SQL: $request");
       }
       $sth->execute();
       my $row = $sth->fetchrow_arrayref();
       if (ref($row) eq 'ARRAY' && scalar(@$row)>0) {
           return @$row;
       }
       return ();
   }
   
 =cut  
   
 sub get_sequence_assessment_data {  sub populate_weight_table {
     return undef;      my ($courseid) = @_;
     my $fn=$ENV{'request.course.fn'};      if (! defined($courseid)) {
     &Apache::lonnet::logthis('filename = '.$fn);          $courseid = $env{'request.course.id'};
     ##  
     ## use navmaps  
     my $navmap = Apache::lonnavmaps::navmap->new($fn.".db",$fn."_parms.db",  
                                                  1,0);  
     if (!defined($navmap)) {  
         return 'Can not open Coursemap';  
     }      }
     my $iterator = $navmap->getIterator(undef, undef, undef, 1);  
     ##  
     ## Prime the pump   
     ##   
     ## We are going to loop until we run out of sequences/pages to explore for  
     ## resources.  This means we have to start out with something to look  
     ## at.  
     my $curRes = $iterator->next(); # BEGIN_MAP  
     $curRes = $iterator->next(); # The sequence itself  
     #  
     my $title = $curRes->title();  
     my $symb  = $curRes->symb();  
     my $src   = $curRes->src();  
     #  
     my @Sequences;   
     my @Assessments;  
     my @Nested_Sequences = ();   # Stack of sequences, keeps track of depth  
     my $top = { title    => $title,  
                 symb     => $symb,  
                 type     => 'container',  
                 num_assess => 0,  
                 contents   => [], };  
     push (@Sequences,$top);  
     push (@Nested_Sequences, $top);  
     #      #
     # We need to keep track of which sequences contain homework problems      &setup_table_names($courseid);
     #       my $navmap = Apache::lonnavmaps::navmap->new();
     while (scalar(@Nested_Sequences)) {      if (!defined($navmap)) {
         $curRes = $iterator->next();          &Apache::lonnet::logthis('loncoursedata::populate_weight_table:'.$/.
         my $currentmap = $Nested_Sequences[-1]; # Last one on the stack                                   '  unable to get navmaps resource'.$/.
         if ($curRes == $iterator->BEGIN_MAP()) {                                   '  '.join(' ',(caller)));
             # get the map itself, instead of BEGIN_MAP          return;
             $curRes = $iterator->next();       }
             $title = $curRes->title();      my @sequences = $navmap->retrieveResources(undef,
             $symb  = $curRes->symb();                                                 sub { shift->is_map(); },1,0,1);
             $src   = $curRes->src();      my @resources;
             my $newmap = { title    => $title,      foreach my $seq (@sequences) {
                            src      => $src,          push(@resources,$navmap->retrieveResources($seq,
                            symb     => $symb,                                                     sub {shift->is_gradable();},
                            type     => 'container',                                                     0,0,0));
                            num_assess => 0,      }
                            contents   => [],      if (! scalar(@resources)) {
                        };          &Apache::lonnet::logthis('loncoursedata::populate_weight_table:'.$/.
             push (@{$currentmap->{'contents'}},$newmap); # this is permanent                                   ' no resources returned for '.$courseid);
             push (@Sequences,$newmap);          return;
             push (@Nested_Sequences, $newmap); # this is a stack      }
             next;      #       Since we use lonnet::EXT to retrieve problem weights,
       #       to ensure current data we must clear the caches out.
       &Apache::lonnet::clear_EXT_cache_status();
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = 'INSERT IGNORE INTO '.$weight_table.
           "(symb_id,part_id,weight) VALUES ";
       my $weight;
       foreach my $res (@resources) {
           my $symb_id = &get_symb_id($res->symb);
           foreach my $part (@{$res->parts}) {
               my $part_id = &get_part_id($part);
               $weight = &Apache::lonnet::EXT('resource.'.$part.'.weight',
                                              $res->symb,
                                              undef,undef,undef);
               if (!defined($weight) || ($weight eq '')) { 
                   $weight=1;
               }
               $request .= "('".$symb_id."','".$part_id."','".$weight."'),";
         }          }
         if ($curRes == $iterator->END_MAP()) {      }
             pop(@Nested_Sequences);      $request =~ s/(,)$//;
             next;  #    &Apache::lonnet::logthis('request = '.$/.$request);
       $dbh->do($request);
       if ($dbh->err()) {
           &Apache::lonnet::logthis("error ".$dbh->errstr().
                                    " occurred executing \n".
                                    $request);
       }
       return;
   }
   
   sub limit_by_start_end_time {
       my ($starttime,$endtime,$table) = @_;
       my $time_requirements = undef;
       if (defined($starttime)) {
           $time_requirements .= $table.".timestamp>='".$starttime."'";
           if (defined($endtime)) {
               $time_requirements .= " AND ".$table.".timestamp<='".$endtime."'";
         }          }
         next if (! ref($curRes));      } elsif (defined($endtime)) {
         next if (! $curRes->is_problem() && !$curRes->randomout);          $time_requirements .= $table.".timestamp<='".$endtime."'";
         # Okay, from here on out we only deal with assessments  
         $title = $curRes->title();  
         $symb  = $curRes->symb();  
         $src   = $curRes->src();  
         my $parts = $curRes->parts();  
         my $assessment = { title => $title,  
                            src   => $src,  
                            symb  => $symb,  
                            type  => 'assessment',  
                        };  
         push(@Assessments,$assessment);  
         push(@{$currentmap->{'contents'}},$assessment);  
         $currentmap->{'num_assess'}++;  
     }      }
     return ($top,\@Sequences,\@Assessments);      return $time_requirements;
 }  }
   
 =pod  
   
 =item &ProcessTopResourceMap()  sub limit_by_section_and_status {
       my ($Sections,$enrollment,$tablename) = @_;
       my $student_requirements = undef;
       if ( (defined($Sections) && $Sections->[0] ne 'all')) {
           $student_requirements = '('.
               join(' OR ', map { $tablename.".section='".$_."'" } @$Sections
                    ).')';
       }
       my $enrollment_requirements=undef;
       if (defined($enrollment) && $enrollment ne 'Any') {
    my $now = time();
    if ( $enrollment eq 'Future' ) {
       $enrollment_requirements = 
    "( $tablename.start > $now AND ".
    "( $tablename.end = 0 OR $tablename.end > $now))";
    } elsif ( $enrollment eq 'Active' ) {
       $enrollment_requirements = 
    "(( $tablename.start = 0 OR $tablename.start < $now )  AND ".
    " ( $tablename.end   = 0 OR $tablename.end   > $now ))";
    } elsif ( $enrollment eq 'Expired' ) {
       $enrollment_requirements = 
    "(( $tablename.start < $now )  AND ".
    " ( $tablename.end   < $now ))";
    }
       }
       return ($student_requirements,$enrollment_requirements);
   }
   
 Trace through the "big hash" created in rat/lonuserstate.pm::loadmap.    
 Basically, this function organizes a subset of the data and stores it in  
 cached data.  The data stored is the problems, sequences, sequence titles,  
 parts of problems, and their ordering.  Column width information is also   
 partially handled here on a per sequence basis.  
   
 =over 4  
   
 Input: $cache, $c  sub limit_by_group {
       my ($Groups,$stutable,$grptable,$stugrptab) = @_;
       my $groups_join = undef;
       my $group_limits = undef;
       if ( (defined($Groups) && $Groups->[0] ne 'all')) {
           $groups_join =
             ' LEFT JOIN '.$students_groups_table.
                        ' AS '.$stugrptab.' ON '.
                        $stugrptab.'.student_id = '.$stutable.'.student_id'.
             ' LEFT JOIN '.$groupnames_table.
                        ' AS '.$grptable.' ON '.
                        $stugrptab.'.group_id = '.$grptable.'.group_id ';
           $group_limits =
             ' ('.
                join(' OR ', map {  "$grptable.groupname='".$_."'" } @$Groups
              ).')';
       }
       return ($groups_join,$group_limits);
   }
   
 $cache:  A pointer to a hash to store the information  
   
 $c:  The connection class used to determine if an abort has been sent to the   sub RNK_student { return 0; };
 browser  sub RNK_score   { return 1; };
   
 Output: A string that contains an error message or "OK" if everything went   sub rank_students_by_scores_on_resources {
 smoothly.      my ($resources,$Sections,$Groups,$enrollment,$courseid,$starttime,$endtime,
           $has_award_for) = @_;
       return if (! defined($resources) || ! ref($resources) eq 'ARRAY');
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       my ($section_limits,$enrollment_limits)=
           &limit_by_section_and_status($Sections,$enrollment,'b');
       my ($groups_join,$group_limits) = &limit_by_group($Groups,'b','c','d');
       my $symb_limits = '('.join(' OR ',map {'a.symb_id='.&get_symb_id($_);
                                          } @$resources
                                  ).')';
       my ($award_col, $award_join, $award_clause) = ('', '', '');
       if ($has_award_for) {
           my $resource_id = &get_symb_id($has_award_for);
           $award_col = ", perf.awarded";
           $award_join = "LEFT JOIN $performance_table AS perf ON perf.symb_id"
               ." = $resource_id AND perf.student_id = b.student_id ";
           $award_clause = "AND perf.awarded IS NOT NULL";
       }
       my $time_limits = &limit_by_start_end_time($starttime,$endtime,'a');
       my $request = "SELECT b.student,SUM(a.awarded*w.weight) AS score "
           ."$award_col FROM $performance_table AS a ".
           "NATURAL LEFT JOIN $weight_table AS w ".
           "LEFT JOIN $student_table AS b ON a.student_id=b.student_id ".
           "$award_join $groups_join "; 
       my $limits;
       if (defined($section_limits)) {
           $limits .= $section_limits.' AND ';
       }
       if (defined($enrollment_limits)) {
           $limits .= $enrollment_limits.' AND ';
       }
       if (defined($time_limits)) {
           $limits .= $time_limits.' AND ';
       }
       if ($symb_limits ne '()') {
           $limits .= $symb_limits.' AND ';
       }
       if (defined($group_limits)) {
           $limits .= $group_limits.' AND ';
       }
       if ($limits) {
           $limits =~ s/( AND )$//;   # Remove extra conjunction
           $request .= "WHERE $limits";
       } 
       $request .= " $award_clause GROUP BY a.student_id ORDER BY score, b.student";
       #&Apache::lonnet::logthis('request = '.$/.$request);
       my $sth = $dbh->prepare($request) or die "Can't prepare $request";
       $sth->execute();
       my $rows = $sth->fetchall_arrayref();
       return ($rows);
   }
   
 =back  sub get_sum_of_scores {
       my ($symb,$part,$students,$courseid,$starttime,$endtime) = @_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       if (defined($students) && 
           ((@$students == 0) ||
            (@$students == 1 && (! defined($students->[0]) || 
                                 $students->[0] eq ''))
            )
           ){
           undef($students);
       }
       #
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       my $time_limits = &limit_by_start_end_time($starttime,$endtime,'a');
       my $request = 'SELECT SUM(a.awarded*w.weight),SUM(w.weight) FROM '.
           $performance_table.' AS a '.
           'NATURAL LEFT JOIN '.$weight_table.' AS w ';
       $request .= 'WHERE a.symb_id='.&get_symb_id($symb).
           ' AND a.part_id='.&get_part_id($part);
       if (defined($time_limits)) {
           $request .= ' AND '.$time_limits;
       }
       if (defined($students)) {
           $request .= ' AND ('.
               join(' OR ',map {'a.student_id='.&get_student_id(split(':',$_));
                            } @$students).
                                ')';
       }
       my $sth = $dbh->prepare($request);
       $sth->execute();
       my $rows = $sth->fetchrow_arrayref();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 1 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed, fetchrow_arrayrefed'.
                                    $/.$request);
           return (undef,undef);
       }
       return ($rows->[0],$rows->[1]);
   }
   
 =cut  
   
 sub ProcessTopResourceMap {  sub score_stats {
     my ($cache,$c)=@_;      my ($Sections,$Groups,$enrollment,$symbs,$starttime,$endtime,$courseid)=@_;
     my %hash;      if (! defined($courseid)) {
     my $fn=$ENV{'request.course.fn'};          $courseid = $env{'request.course.id'};
     if(-e "$fn.db") {  
  my $tieTries=0;  
  while($tieTries < 3) {  
             if($c->aborted()) {  
                 return;  
             }  
     if(tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {  
  last;  
     }  
     $tieTries++;  
     sleep 1;  
  }  
  if($tieTries >= 3) {  
             return 'Coursemap undefined.';  
         }  
     } else {  
         return 'Can not open Coursemap.';  
     }      }
       #
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       #
       my ($section_limits,$enrollment_limits)=
           &limit_by_section_and_status($Sections,$enrollment,'b');
       my ($groups_join,$group_limits) = &limit_by_group($Groups,'b','c','d');
       my $time_limits = &limit_by_start_end_time($starttime,$endtime,'a');
       my @Symbids = map { &get_symb_id($_); } @{$symbs};
       #
       my $stats_table = &temp_table_name($courseid,'problem_stats');
       my $symb_restriction = join(' OR ',map {'a.symb_id='.$_;} @Symbids);
       my $request = 'DROP TABLE '.$stats_table;
       $dbh->do($request);
       $request = 
           'CREATE TEMPORARY TABLE '.$stats_table.' '.
           'SELECT a.student_id,'.
           'SUM(a.awarded*w.weight) AS score FROM '.
           $performance_table.' AS a '.
           'NATURAL LEFT JOIN '.$weight_table.' AS w '.
           'LEFT JOIN '.$student_table.' AS b ON a.student_id=b.student_id '.
           $groups_join;
       my $limit = ' WHERE ('.$symb_restriction.')';
       if ($time_limits) {
           $limit .= ' AND '.$time_limits;
       }
       if ($section_limits) {
           $limit .= ' AND '.$section_limits;
       }
       if ($enrollment_limits) {
           $limit .= ' AND '.$enrollment_limits;
       }
       if ($group_limits) {
           $limit .= ' AND '.$group_limits;
       }
       $request .= $limit.' GROUP BY a.student_id';
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       $request = 
           'SELECT AVG(score),STD(score),MAX(score),MIN(score),COUNT(score) '.
           'FROM '.$stats_table;
       my ($ave,$std,$max,$min,$count) = &execute_SQL_request($dbh,$request);
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       
       $request = 'SELECT SUM(weight) FROM '.$weight_table.
           ' AS a WHERE ('.$symb_restriction.')';
       my ($max_possible) = &execute_SQL_request($dbh,$request);
       # &Apache::lonnet::logthis('request = '.$/.$request);
       return($min,$max,$ave,$std,$count,$max_possible);
   }
   
     my $oldkeys;  
     delete $cache->{'OptionResponses'};  
     if(defined($cache->{'ResourceKeys'})) {  
         $oldkeys = $cache->{'ResourceKeys'};  
         foreach (split(':::', $cache->{'ResourceKeys'})) {  
             delete $cache->{$_};  
         }  
         delete $cache->{'ResourceKeys'};  
     }  
   
     # Initialize state machine.  Set information pointing to top level map.  
     my (@sequences, @currentResource, @finishResource);  
     my ($currentSequence, $currentResourceID, $lastResourceID);  
   
     $currentResourceID=$hash{'ids_'.  
       &Apache::lonnet::clutter($ENV{'request.course.uri'})};  
     push(@currentResource, $currentResourceID);  
     $lastResourceID=-1;  
     $currentSequence=-1;  
     my $topLevelSequenceNumber = $currentSequence;  
   
     my %sequenceRecord;  
     my %allkeys;  
     while(1) {  
         if($c->aborted()) {  
             last;  
         }  
  # HANDLE NEW SEQUENCE!  
  #if page || sequence  
  if(defined($hash{'map_pc_'.$hash{'src_'.$currentResourceID}}) &&  
            !defined($sequenceRecord{$currentResourceID})) {  
             $sequenceRecord{$currentResourceID}++;  
     push(@sequences, $currentSequence);  
     push(@currentResource, $currentResourceID);  
     push(@finishResource, $lastResourceID);  
   
     $currentSequence=$hash{'map_pc_'.$hash{'src_'.$currentResourceID}};  
   
             # Mark sequence as containing problems.  If it doesn't, then  
             # it will be removed when processing for this sequence is  
             # complete.  This allows the problems in a sequence  
             # to be outputed before problems in the subsequences  
             if(!defined($cache->{'orderedSequences'})) {  
                 $cache->{'orderedSequences'}=$currentSequence;  
             } else {  
                 $cache->{'orderedSequences'}.=':'.$currentSequence;  
             }  
             $allkeys{'orderedSequences'}++;  
   
     $lastResourceID=$hash{'map_finish_'.  
   $hash{'src_'.$currentResourceID}};  
     $currentResourceID=$hash{'map_start_'.  
      $hash{'src_'.$currentResourceID}};  
   
     if(!($currentResourceID) || !($lastResourceID)) {  
  $currentSequence=pop(@sequences);  
  $currentResourceID=pop(@currentResource);  
  $lastResourceID=pop(@finishResource);  
  if($currentSequence eq $topLevelSequenceNumber) {  
     last;  
  }  
     }  
             next;  
  }  
   
  # Handle gradable resources: exams, problems, etc  sub count_stats {
  $currentResourceID=~/(\d+)\.(\d+)/;      my ($Sections,$Groups,$enrollment,$symbs,$starttime,$endtime,$courseid)=@_;
         my $partA=$1;      if (! defined($courseid)) {
         my $partB=$2;          $courseid = $env{'request.course.id'};
  if($hash{'src_'.$currentResourceID}=~      }
    /\.(problem|exam|quiz|assess|survey|form)$/ &&      #
    $partA eq $currentSequence &&       &setup_table_names($courseid);
            !defined($sequenceRecord{$currentSequence.':'.      my $dbh = &Apache::lonmysql::get_dbh();
                                     $currentResourceID})) {      #
             $sequenceRecord{$currentSequence.':'.$currentResourceID}++;      my ($section_limits,$enrollment_limits)=
     my $Problem = &Apache::lonnet::symbclean(          &limit_by_section_and_status($Sections,$enrollment,'b');
   &Apache::lonnet::declutter($hash{'map_id_'.$partA}).      my ($groups_join,$group_limits) = &limit_by_group($Groups,'b','c','d');
   '___'.$partB.'___'.      my $time_limits = &limit_by_start_end_time($starttime,$endtime,'a');
   &Apache::lonnet::declutter($hash{'src_'.      my @Symbids = map { &get_symb_id($_); } @{$symbs};
  $currentResourceID}));      #
       my $stats_table = &temp_table_name($courseid,'problem_stats');
     $cache->{$currentResourceID.':problem'}=$Problem;      my $symb_restriction = join(' OR ',map {'a.symb_id='.$_;} @Symbids);
             $allkeys{$currentResourceID.':problem'}++;      my $request = 'DROP TABLE '.$stats_table;
     if(!defined($cache->{$currentSequence.':problems'})) {      $dbh->do($request);
  $cache->{$currentSequence.':problems'}=$currentResourceID;      $request = 
     } else {          'CREATE TEMPORARY TABLE '.$stats_table.' '.
  $cache->{$currentSequence.':problems'}.=          'SELECT a.student_id,'.
     ':'.$currentResourceID;          'SUM(a.awarded) AS count FROM '.
     }          $performance_table.' AS a '.
             $allkeys{$currentSequence.':problems'}++;          'LEFT JOIN '.$student_table.' AS b ON a.student_id=b.student_id '.
           $groups_join;
       my $limit =  ' WHERE ('.$symb_restriction.')';
       if ($time_limits) {
           $limit .= ' AND '.$time_limits;
       }
       if ($section_limits) {
           $limit .= ' AND '.$section_limits;
       }
       if ($enrollment_limits) {
           $limit .= ' AND '.$enrollment_limits;
       }
       if ($group_limits) {
           $limit .= ' AND '.$group_limits;
       }
       $request .= $limit.' GROUP BY a.student_id';
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       $request = 
           'SELECT AVG(count),STD(count),MAX(count),MIN(count),COUNT(count) '.
           'FROM '.$stats_table;
       my ($ave,$std,$max,$min,$count) = &execute_SQL_request($dbh,$request);
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       return($min,$max,$ave,$std,$count);
   }
   
     my $meta=$hash{'src_'.$currentResourceID};  
 #            $cache->{$currentResourceID.':title'}=  
 #                &Apache::lonnet::metdata($meta,'title');  
             $cache->{$currentResourceID.':title'}=  
                 $hash{'title_'.$currentResourceID};  
             $allkeys{$currentResourceID.':title'}++;  
             $cache->{$currentResourceID.':source'}=  
                 $hash{'src_'.$currentResourceID};  
             $allkeys{$currentResourceID.':source'}++;  
   
             # Get Parts for problem  
             my %beenHere;  
             foreach (split(/\,/,&Apache::lonnet::metadata($meta,'packages'))) {  
                 if(/^\w+response_\d+.*/) {  
                     my (undef, $partId, $responseId) = split(/_/,$_);  
                     if($beenHere{'p:'.$partId} ==  0) {  
                         $beenHere{'p:'.$partId}++;  
                         if(!defined($cache->{$currentSequence.':'.  
                                             $currentResourceID.':parts'})) {  
                             $cache->{$currentSequence.':'.$currentResourceID.  
                                      ':parts'}=$partId;  
                         } else {  
                             $cache->{$currentSequence.':'.$currentResourceID.  
                                      ':parts'}.=':'.$partId;  
                         }  
                         $allkeys{$currentSequence.':'.$currentResourceID.  
                                   ':parts'}++;  
                     }  
                     if($beenHere{'r:'.$partId.':'.$responseId} == 0) {  
                         $beenHere{'r:'.$partId.':'.$responseId}++;  
                         if(!defined($cache->{$currentSequence.':'.  
                                              $currentResourceID.':'.$partId.  
                                              ':responseIDs'})) {  
                             $cache->{$currentSequence.':'.$currentResourceID.  
                                      ':'.$partId.':responseIDs'}=$responseId;  
                         } else {  
                             $cache->{$currentSequence.':'.$currentResourceID.  
                                      ':'.$partId.':responseIDs'}.=':'.  
                                                                   $responseId;  
                         }  
                         $allkeys{$currentSequence.':'.$currentResourceID.':'.  
                                      $partId.':responseIDs'}++;  
                     }  
                     if(/^optionresponse/ &&   
                        $beenHere{'o:'.$partId.':'.$currentResourceID} == 0) {  
                         $beenHere{'o:'.$partId.$currentResourceID}++;  
                         if(defined($cache->{'OptionResponses'})) {  
                             $cache->{'OptionResponses'}.= ':::'.  
                                 $currentSequence.':'.$currentResourceID.':'.  
                                 $partId.':'.$responseId;  
                         } else {  
                             $cache->{'OptionResponses'}= $currentSequence.':'.  
                                 $currentResourceID.':'.  
                                 $partId.':'.$responseId;  
                         }  
                         $allkeys{'OptionResponses'}++;  
                     }  
                 }  
             }  
         }  
   
  # if resource == finish resource, then it is the end of a sequence/page  sub get_student_data {
  if($currentResourceID eq $lastResourceID) {      my ($students,$courseid) = @_;
     # pop off last resource of sequence      $courseid = $env{'request.course.id'} if (! defined($courseid));
     $currentResourceID=pop(@currentResource);      &setup_table_names($courseid);
     $lastResourceID=pop(@finishResource);      my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
     if(defined($cache->{$currentSequence.':problems'})) {      my $request = 'SELECT '.
  # Capture sequence information here          'student_id, student '.
  $cache->{$currentSequence.':title'}=          'FROM '.$student_table;
     $hash{'title_'.$currentResourceID};      if (defined($students)) {
                 $allkeys{$currentSequence.':title'}++;          $request .= ' WHERE ('.
                 $cache->{$currentSequence.':source'}=              join(' OR ', map {'student_id='.
                     $hash{'src_'.$currentResourceID};                                    &get_student_id($_->{'username'},
                 $allkeys{$currentSequence.':source'}++;                                                    $_->{'domain'})
                                 } @$students
                 my $totalProblems=0;                   ).')';
                 foreach my $currentProblem (split(/\:/,      }
                                                $cache->{$currentSequence.      $request.= ' ORDER BY student_id';
                                                ':problems'})) {      my $sth = $dbh->prepare($request);
                     foreach (split(/\:/,$cache->{$currentSequence.':'.      $sth->execute();
                                                    $currentProblem.      if ($dbh->err) {
                                                    ':parts'})) {          &Apache::lonnet::logthis('error 2 = '.$dbh->errstr());
                         $totalProblems++;          &Apache::lonnet::logthis('prepared then executed '.$/.$request);
                     }          return undef;
                 }      }
  my @titleLength=split(//,$cache->{$currentSequence.      my $dataset = $sth->fetchall_arrayref();
                                                     ':title'});      if (ref($dataset) eq 'ARRAY' && scalar(@$dataset)>0) {
                 # $extra is 5 for problems correct and 3 for space          return $dataset;
                 # between problems correct and problem output      }
                 my $extra = 8;  }
  if(($totalProblems + $extra) > (scalar @titleLength)) {  
     $cache->{$currentSequence.':columnWidth'}=  
                         $totalProblems + $extra;  
  } else {  
     $cache->{$currentSequence.':columnWidth'}=  
                         (scalar @titleLength);  
  }  
                 $allkeys{$currentSequence.':columnWidth'}++;  
     } else {  
                 # Remove sequence from list, if it contains no problems to  
                 # display.  
                 $cache->{'orderedSequences'}=~s/$currentSequence//;  
                 $cache->{'orderedSequences'}=~s/::/:/g;  
                 $cache->{'orderedSequences'}=~s/^:|:$//g;  
             }  
   
     $currentSequence=pop(@sequences);  sub RD_student_id      { return 0; }
     if($currentSequence eq $topLevelSequenceNumber) {  sub RD_awarddetail     { return 1; }
  last;  sub RD_response_eval   { return 2; }
     }  sub RD_response_eval_2 { return 3; }
   sub RD_submission      { return 4; }
   sub RD_timestamp       { return 5; }
   sub RD_tries           { return 6; }
   sub RD_sname           { return 7; }
   
   sub get_response_data {
       my ($Sections,$Groups,$enrollment,$symb,$response,$courseid) = @_;
       return undef if (! defined($symb) || 
                  ! defined($response));
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       my $symb_id = &get_symb_id($symb);
       if (! defined($symb_id)) {
           &Apache::lonnet::logthis('Unable to find symb for '.$symb.' in '.$courseid);
           return undef;
       }
       my $response_id = &get_part_id($response);
       if (! defined($response_id)) {
           &Apache::lonnet::logthis('Unable to find id for '.$response.' in '.$courseid);
           return undef;
       }
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       #
       my ($student_requirements,$enrollment_requirements) = 
           &limit_by_section_and_status($Sections,$enrollment,'d');
       my ($groups_join,$group_limits) = &limit_by_group($Groups,'d','e','f');
       my $request = 'SELECT '.
           'a.student_id, a.awarddetail, a.response_specific_value, '.
           'a.response_specific_value_2, a.submission, b.timestamp, '.
    'c.tries, d.student '.
           'FROM '.$fulldump_response_table.' AS a '.
           'LEFT JOIN '.$fulldump_timestamp_table.' AS b '.
           'ON a.symb_id=b.symb_id AND a.student_id=b.student_id AND '.
           'a.transaction = b.transaction '.
           'LEFT JOIN '.$fulldump_part_table.' AS c '.
           'ON a.symb_id=c.symb_id AND a.student_id=c.student_id AND '.        
           'a.part_id=c.part_id AND a.transaction = c.transaction '.
           'LEFT JOIN '.$student_table.' AS d '.
           'ON a.student_id=d.student_id '.
           $groups_join;
       my $limit = ' WHERE '.
           'a.symb_id='.$symb_id.' AND a.response_id='.$response_id;
       if (defined($student_requirements)) {
           $limit .= ' AND '.$student_requirements;
       }
       if (defined($enrollment_requirements)) {
           $limit .= ' AND '.$enrollment_requirements;
       }
       if (defined($group_limits)) {
           $limit .= ' AND '.$group_limits;
       }
       $request .= $limit.' ORDER BY b.timestamp';
   #    &Apache::lonnet::logthis("request =\n".$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 3 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       my $dataset = $sth->fetchall_arrayref();
       if (ref($dataset) eq 'ARRAY' && scalar(@$dataset)>0) {
           # Clear the \'s from around the submission
           for (my $i =0;$i<scalar(@$dataset);$i++) {
               $dataset->[$i]->[&RD_submission()] =~ s/(\'$|^\')//g;
         }          }
           return $dataset;
  # MOVE!!!  
  # move to next resource  
  unless(defined($hash{'to_'.$currentResourceID})) {  
     # big problem, need to handle.  Next is probably wrong  
             my $errorMessage = 'Big problem in ';  
             $errorMessage .= 'loncoursedata::ProcessTopLevelMap.';  
             $errorMessage .= "  bighash to_$currentResourceID not defined!";  
             &Apache::lonnet::logthis($errorMessage);  
     if (!defined($currentResourceID)) {last;}  
  }  
  my @nextResources=();  
  foreach (split(/\,/,$hash{'to_'.$currentResourceID})) {  
             if(!defined($sequenceRecord{$currentSequence.':'.  
                                         $hash{'goesto_'.$_}})) {  
                 push(@nextResources, $hash{'goesto_'.$_});  
             }  
  }  
  push(@currentResource, @nextResources);  
  # Set the next resource to be processed  
  $currentResourceID=pop(@currentResource);  
     }      }
   }
   
     my @theKeys = keys(%allkeys);  
     my $newkeys = join(':::', @theKeys);  sub RDs_awarddetail     { return 3; }
     $cache->{'ResourceKeys'} = join(':::', $newkeys);  sub RDs_submission      { return 2; }
     if($newkeys ne $oldkeys) {  sub RDs_timestamp       { return 1; }
         $cache->{'ResourceUpdated'} = 'true';  sub RDs_tries           { return 0; }
     } else {  sub RDs_awarded         { return 4; }
         $cache->{'ResourceUpdated'} = 'false';  sub RDs_response_eval   { return 5; }
   sub RDs_response_eval_2 { return 6; }
   sub RDs_part_award      { return 7; }
   
   sub get_response_data_by_student {
       my ($student,$symb,$response,$courseid) = @_;
       return undef if (! defined($symb) || 
                        ! defined($response));
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       my $symb_id = &get_symb_id($symb);
       my $response_id = &get_part_id($response);
       #
       my $student_id = &get_student_id($student->{'username'},
                                        $student->{'domain'});
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       my $request = 'SELECT '.
           'c.tries, b.timestamp, a.submission, a.awarddetail, c.awarded, '.
    'a.response_specific_value, a.response_specific_value_2, c.award '.
           'FROM '.$fulldump_response_table.' AS a '.
           'LEFT JOIN '.$fulldump_timestamp_table.' AS b '.
           'ON a.symb_id=b.symb_id AND a.student_id=b.student_id AND '.
           'a.transaction = b.transaction '.
           'LEFT JOIN '.$fulldump_part_table.' AS c '.
           'ON a.symb_id=c.symb_id AND a.student_id=c.student_id AND '.        
           'a.part_id=c.part_id AND a.transaction = c.transaction '.
           'LEFT JOIN '.$student_table.' AS d '.
           'ON a.student_id=d.student_id '.
           'LEFT JOIN '.$performance_table.' AS e '.
           'ON a.symb_id=e.symb_id AND a.part_id=e.part_id AND '.
           'a.student_id=e.student_id AND c.tries=e.tries '.
           'WHERE '.
           'a.symb_id='.$symb_id.' AND a.response_id='.$response_id.
           ' AND a.student_id='.$student_id.' ORDER BY b.timestamp';
   #    &Apache::lonnet::logthis("request =\n".$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 4 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       my $dataset = $sth->fetchall_arrayref();
       if (ref($dataset) eq 'ARRAY' && scalar(@$dataset)>0) {
           # Clear the \'s from around the submission
           for (my $i =0;$i<scalar(@$dataset);$i++) {
               $dataset->[$i]->[&RDs_submission] =~ s/(\'$|^\')//g;
           }
           return $dataset;
     }      }
       return undef; # error occurred
   }
   
     unless (untie(%hash)) {  sub RT_student_id { return 0; }
         &Apache::lonnet::logthis("<font color=blue>WARNING: ".  sub RT_awarded    { return 1; }
                                  "Could not untie coursemap $fn (browse)".  sub RT_tries      { return 2; }
                                  ".</font>");   sub RT_timestamp  { return 3; }
   
   sub get_response_time_data {
       my ($sections,$groups,$enrollment,$symb,$part,$courseid) = @_;
       return undef if (! defined($symb) || 
                        ! defined($part));
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       my $symb_id = &get_symb_id($symb);
       if (! defined($symb_id)) {
           &Apache::lonnet::logthis('Unable to find symb for '.$symb.' in '.$courseid);
           return undef;
       }
       my $part_id = &get_part_id($part);
       if (! defined($part_id)) {
           &Apache::lonnet::logthis('Unable to find id for '.$part.' in '.$courseid);
           return undef;
       }
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       my ($student_requirements,$enrollment_requirements) = 
           &limit_by_section_and_status($sections,$enrollment,'d');
       my ($groups_join,$group_limits) = &limit_by_group($groups,'d','e','f');
       my $request = 'SELECT '.
           'a.student_id, a.awarded, a.tries, b.timestamp '.
           'FROM '.$fulldump_part_table.' AS a '.
           'LEFT JOIN '.$fulldump_timestamp_table.' AS b '.
           'ON a.symb_id=b.symb_id AND a.student_id=b.student_id AND '.
           'a.transaction = b.transaction '.
           'LEFT JOIN '.$student_table.' as d '.
           'ON a.student_id=d.student_id '.
           $groups_join;
       my $limit = ' WHERE '.
           'a.symb_id='.$symb_id.' AND a.part_id='.$part_id;
       if (defined($student_requirements)) {
           $limit .= ' AND '.$student_requirements;
       }
       if (defined($enrollment_requirements)) {
           $limit .= ' AND '.$enrollment_requirements;
       }
       if (defined($group_limits)) {
           $limit .= ' AND '.$group_limits;  
       }
       $request .= $limit.' ORDER BY b.timestamp';
   #    &Apache::lonnet::logthis("request =\n".$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 5 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       my $dataset = $sth->fetchall_arrayref();
       if (ref($dataset) eq 'ARRAY' && scalar(@$dataset)>0) {
           return $dataset;
     }      }
   
     return 'OK';  
 }  }
   
 =pod  sub get_student_scores {
       my ($sections,$groups,$Symbs,$enrollment,$courseid,$starttime,$endtime) = @_;
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       return (undef) if (! defined($dbh));
       my $tmptable = &temp_table_name($courseid,'temp_'.time);
       my $request = 'DROP TABLE IF EXISTS '.$tmptable;
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       $dbh->do($request);
       #
       my $symb_requirements;
       if (defined($Symbs)  && @$Symbs) {
           $symb_requirements = '('.
               join(' OR ', map{ "(a.symb_id='".&get_symb_id($_->{'symb'}).
                                 "' AND a.part_id='".&get_part_id($_->{'part'}).
                                 "')"
                                 } @$Symbs).')';
       }
       #
       my ($student_requirements,$enrollment_requirements) = 
           &limit_by_section_and_status($sections,$enrollment,'b');
       #
       my ($groups_join,$group_limits) = &limit_by_group($groups,'b','d','e');
       my $time_requirements = &limit_by_start_end_time($starttime,$endtime,'a');
       ##
       $request = 'CREATE TEMPORARY TABLE IF NOT EXISTS '.$tmptable.
           ' SELECT a.student_id,SUM(a.awarded*c.weight) AS score FROM '.
           $performance_table.' AS a ';
       $request .= "LEFT JOIN ".$weight_table.' AS c ON a.symb_id=c.symb_id AND a.part_id=c.part_id ';
       if (defined($student_requirements) || defined($enrollment_requirements)) {
           $request .= ' LEFT JOIN '.$student_table.' AS b ON a.student_id=b.student_id ';
       }
       if (defined($groups_join)) {
           $request .= $groups_join;
       }
       if (defined($symb_requirements)       || 
           defined($student_requirements)    ||
           defined($enrollment_requirements) ||
           defined($group_limits) ) {
           $request .= ' WHERE ';
       }
       if (defined($symb_requirements)) {
           $request .= $symb_requirements.' AND ';
       }
       if (defined($student_requirements)) {
           $request .= $student_requirements.' AND ';
       }
       if (defined($enrollment_requirements)) {
           $request .= $enrollment_requirements.' AND ';
       }
       if (defined($time_requirements)) {
           $request .= $time_requirements.' AND ';
       }
       $request =~ s/ AND $//; # Strip of the trailing ' AND '.
       $request .= ' GROUP BY a.student_id';
   #    &Apache::lonnet::logthis("request = \n".$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 6 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       $request = 'SELECT score,COUNT(*) FROM '.$tmptable.' GROUP BY score';
   #    &Apache::lonnet::logthis("request = \n".$request);
       $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 7 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       my $dataset = $sth->fetchall_arrayref();
       return $dataset;
   }
   
 =item &ProcessClasslist()  
   
 Taking the class list dumped from &DownloadClasslist(), all the   
 students and their non-class information is processed using the   
 &ProcessStudentInformation() function.  A date stamp is also recorded for  
 when the data was processed.  
   
 Takes data downloaded for a student and breaks it up into managable pieces and   
 stored in cache data.  The username, domain, class related date, PID,   
 full name, and section are all processed here.  
   
 =over 4  sub setup_table_names {
       my ($courseid) = @_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       if (! defined($current_course) || $current_course ne $courseid) {
           # Clear out variables
           $have_read_part_table = 0;
           undef(%ids_by_part);
           undef(%parts_by_id);
           $have_read_symb_table = 0;
           undef(%ids_by_symb);
           undef(%symbs_by_id);
           $have_read_student_table = 0;
           undef(%ids_by_student);
           undef(%students_by_id);
           $have_read_groupnames_table = 0;
           undef(%ids_by_groupname);
           #
           $current_course = $courseid;
       }
       #
       # Set up database names
       my $base_id = 'md5_'.&Digest::MD5::md5_hex($courseid);
       $symb_table               = $base_id.'_'.'symb';
       $part_table               = $base_id.'_'.'part';
       $student_table            = $base_id.'_'.'student';
       $groupnames_table         = $base_id.'_'.'groupnames';
       $students_groups_table    = $base_id.'_'.'studentgroups';
       $performance_table        = $base_id.'_'.'performance';
       $parameters_table         = $base_id.'_'.'parameters';
       $fulldump_part_table      = $base_id.'_'.'partdata';
       $fulldump_response_table  = $base_id.'_'.'responsedata';
       $fulldump_timestamp_table = $base_id.'_'.'timestampdata';
       $weight_table             = $base_id.'_'.'weight';
       #
       @Tables = (
                  $symb_table,
                  $part_table,
                  $student_table,
                  $groupnames_table,
                  $students_groups_table,
                  $performance_table,
                  $parameters_table,
                  $fulldump_part_table,
                  $fulldump_response_table,
                  $fulldump_timestamp_table,
                  $weight_table,
                  );
       return;
   }
   
 Input: $cache, $classlist, $courseID, $ChartDB, $c  sub temp_table_name {
       my ($courseid,$affix) = @_;
       my $base_id = 'md5_'.&Digest::MD5::md5_hex($courseid);
       return $base_id.'_'.$affix;
   }
   
 $cache: A hash pointer to store the data  
   
 $classlist:  The hash of data collected about a student from   } # End scope of table identifiers
 &DownloadClasslist().  The hash contains a list of students, a pointer   
 to a hash of student information for each student, and each students section   
 number.  
   
 $courseID:  The course ID  
   
 $ChartDB:  The name of the cache database file.  
   
 $c:  The connection class used to determine if an abort has been sent to the   
 browser  
   
 Output: @names  
   
 @names:  An array of students whose information has been processed, and are to   
 be considered in an arbitrary order.  The entries in @names are of the form  
 username:domain.  
   
 The values in $cache are as follows:  
   
  *NOTE: for the following $name implies username:domain  
  $name.':error'                  only defined if an error occured.  Value  
                                  contains the error message  
  $name.':lastDownloadTime'       unconverted time of the last update of a  
                                  student\'s course data  
  $name.'updateTime'              coverted time of the last update of a   
                                  student\'s course data  
  $name.':username'               username of a student  
  $name.':domain'                 domain of a student  
  $name.':fullname'               full name of a student  
  $name.':id'                     PID of a student  
  $name.':Status'                 active/expired status of a student  
  $name.':section'                section of a student  
   
 =back  
   
 =cut  
   
 sub ProcessClasslist {  sub CL_SDOM     { return 0; }
     my ($cache,$classlist,$courseID,$c)=@_;  sub CL_SNAME    { return 1; }
     my @names=();  sub CL_END      { return 2; }
   sub CL_START    { return 3; }
     $cache->{'ClasslistTimeStamp'}=$classlist->{'lastDownloadTime'};  sub CL_ID       { return 4; }
     if($classlist->{'UpToDate'} eq 'true') {  sub CL_SECTION  { return 5; }
         return split(/:::/,$cache->{'NamesOfStudents'});;  sub CL_FULLNAME { return 6; }
     }  sub CL_STATUS   { return 7; }
   sub CL_TYPE     { return 8; }
   sub CL_LOCKEDTYPE   { return 9; }
   sub CL_CREDITS  { return 10; }
   sub CL_INSTSEC { return 11; }
   sub CL_GROUP    { return 12; }
   sub CL_PERMANENTEMAIL { return 13; }
   sub CL_ROLE     { return 14; }
   sub CL_EXTENT   { return 15; }
   sub CL_PHOTO   { return 16; }
   sub CL_THUMBNAIL { return 17; }
   sub CL_AUTHORQUOTA { return 18; }
   sub CL_AUTHORUSAGE { return 19; }
   
     foreach my $name (keys(%$classlist)) {  sub get_classlist {
         if($name =~ /\:section/ || $name =~ /\:studentInformation/ ||      my ($cdom,$cnum) = @_;
            $name eq '' || $name eq 'UpToDate' || $name eq 'lastDownloadTime') {      my $cid = $cdom.'_'.$cnum;
             next;      if (!defined($cdom) || !defined($cnum)) {
         }   $cid =  $env{'request.course.id'};
         if($c->aborted()) {   $cdom = $env{'course.'.$cid.'.domain'};
             return ();   $cnum = $env{'course.'.$cid.'.num'};
       }
       my $now = time;
       #
       my %classlist=&Apache::lonnet::dump('classlist',$cdom,$cnum);
       while (my ($student,$info) = each(%classlist)) {
           if ($student =~ /^(con_lost|error|no_such_host)/i) {
               &Apache::lonnet::logthis('get_classlist error for '.$cid.':'.$student);
               return undef;
         }          }
         my $studentInformation = $classlist->{$name.':studentInformation'};          my ($sname,$sdom) = split(/:/,$student);
         my $date = $classlist->{$name};          my @Values = split(/:/,$info);
         my ($studentName,$studentDomain) = split(/\:/,$name);          my ($end,$start,$id,$section,$fullname,$type,$lockedtype,$credits,$instsec);
           if (@Values > 2) {
         $cache->{$name.':username'}=$studentName;              ($end,$start,$id,$section,$fullname,$type,$lockedtype,$credits,$instsec) = @Values;
         $cache->{$name.':domain'}=$studentDomain;          } else { # We have to get the data ourselves
         # Initialize timestamp for student              ($end,$start) = @Values;
         if(!defined($cache->{$name.':lastDownloadTime'})) {              $section = &Apache::lonnet::getsection($sdom,$sname,$cid);
             $cache->{$name.':lastDownloadTime'}='Not downloaded';              my %info=&Apache::lonnet::get('environment',
             $cache->{$name.':updateTime'}=' Not updated';                                            ['firstname','middlename',
         }                                             'lastname','generation','id'],
                                             $sdom, $sname);
         my $error = 0;              my ($tmp) = keys(%info);
         foreach(keys(%$studentInformation)) {              if ($tmp =~/^(con_lost|error|no_such_host)/i) {
             if(/^(con_lost|error|no_such_host)/i) {                  $fullname = 'not available';
                 $cache->{$name.':error'}=                  $id = 'not available';
                     'Could not download student environment data.';                  &Apache::lonnet::logthis('unable to retrieve environment '.
                 $cache->{$name.':fullname'}='';                                           'for '.$sname.':'.$sdom);
                 $cache->{$name.':id'}='';              } else {
                 $error = 1;                  $fullname = &Apache::lonnet::format_name(@info{qw/firstname middlename lastname generation/},'lastname');
             }                  $id = $info{'id'};
         }              }
         next if($error);              # Update the classlist with this students information
         push(@names,$name);              if ($fullname ne 'not available') {
         $cache->{$name.':fullname'}=&ProcessFullName(   my $enrolldata = join(':',$end,$start,$id,$section,$fullname);
                                           $studentInformation->{'lastname'},   my $reply=&Apache::lonnet::cput('classlist',
                                           $studentInformation->{'generation'},                                                  {$student => $enrolldata},
                                           $studentInformation->{'firstname'},                                                  $cdom,$cnum);
                                           $studentInformation->{'middlename'});                  if ($reply !~ /^(ok|delayed)/) {
         $cache->{$name.':id'}=$studentInformation->{'id'};                      &Apache::lonnet::logthis('Unable to update classlist for '.
                                                'student '.$sname.':'.$sdom.
         my ($end, $start)=split(':',$date);                                               ' error:'.$reply);
         $courseID=~s/\_/\//g;  
         $courseID=~s/^(\w)/\/$1/;  
   
         my $sec='';  
         my $sectionData = $classlist->{$name.':sections'};  
         foreach my $key (keys (%$sectionData)) {  
             my $value = $sectionData->{$key};  
             if ($key=~/^$courseID(?:\/)*(\w+)*\_st$/) {  
                 my $tempsection=$1;  
                 if($key eq $courseID.'_st') {  
                     $tempsection='';  
                 }  
                 my (undef,$roleend,$rolestart)=split(/\_/,$value);  
                 if($roleend eq $end && $rolestart eq $start) {  
                     $sec = $tempsection;  
                     last;  
                 }                  }
             }              }
         }          }
   
         my $status='Expired';          my $status='Expired';
         if(((!$end) || time < $end) && ((!$start) || (time > $start))) {          if(((!$end) || $now < $end) && ((!$start) || ($now > $start))) {
             $status='Active';              $status='Active';
         }          }
         $cache->{$name.':Status'}=$status;          if(($now < $start) && ((!$end) || $now < $end )) {
         $cache->{$name.':section'}=$sec;              $status='Future';
           }
           $classlist{$student} = 
               [$sdom,$sname,$end,$start,$id,$section,$fullname,$status,$type,
                $lockedtype,$credits,$instsec];
       }
       if (wantarray()) {
           return (\%classlist,['domain','username','end','start','id',
                                'section','fullname','status','type',
                                'lockedtype','credits','instsec']);
       } else {
           return \%classlist;
       }
   }
   
         if($sec eq '' || !defined($sec) || $sec eq ' ') {  sub get_group_memberships {
             $sec = 'none';      my ($classlist,$keylist,$cdom,$cnum) = @_;
   
       return ({},{}) if (!ref($classlist) || !ref($keylist));
   
       my $cid = $cdom.'_'.$cnum;
       if (!defined($cdom) || !defined($cnum)) {
           $cid =  $env{'request.course.id'};
           $cdom = $env{'course.'.$cid.'.domain'};
           $cnum = $env{'course.'.$cid.'.num'};
       }
       my (%classgroups,%studentgroups);
       my $now = time;
       my $access_end = $env{'course.'.$cid.'.default_enrollment_end_date'};
       my %curr_groups =&Apache::longroup::coursegroups($cdom,$cnum);
       if (%curr_groups) {
           my $grpindex = &CL_GROUP();
           my %groupmemberhash = 
       &Apache::lonnet::get_group_membership($cdom,$cnum);
           foreach my $student (keys(%{$classlist})) {
               %{$classgroups{$student}} = ();
               my $hasgroup = 0;
               foreach my $status ('previous','future','active','aftercourse') {
                   %{$classgroups{$student}{$status}} = ();
               }
               foreach my $group (keys(%curr_groups)) {
                   if (defined($groupmemberhash{$group.':'.$student})) {
                       my ($end,$start) = split(/:/,$groupmemberhash{$group.':'.
                                                                       $student});
                       if ($start == -1) {
                           next;
                       } else {
                           $studentgroups{$group} ++;
                           $hasgroup = 1;
                           if ($end && $end < $now) {
                               $classgroups{$student}{'previous'}{$group} =
                                            $groupmemberhash{$group.':'.$student};
                               if ($classlist->{$student}[&CL_STATUS()] eq 'Expired') {
                                   if ($access_end && $access_end < $now) {
                                       if ($access_end - $end < 86400) {
                                           $classgroups{$student}{'aftercourse'}{$group} = $groupmemberhash{$group.':'.$student};
                                       }
                                   }
                               }
                           } elsif ($now > $start) {
                               if (!$end || $end > $now) {
                                   $classgroups{$student}{'active'}{$group} =
                                            $groupmemberhash{$group.':'.$student};
                               }
                           } else {
                               $classgroups{$student}{'future'}{$group} =
                                            $groupmemberhash{$group.':'.$student};
                           }
                       }
                   }
               }
               if (!$hasgroup) {
                   $studentgroups{'none'} ++;
               } else {
                   $classlist->{$student}->[$grpindex] = join(',',
                                 sort(keys(%{$classgroups{$student}{'active'}})));
               }
         }          }
         if(defined($cache->{'sectionList'})) {      }
             if($cache->{'sectionList'} !~ /(^$sec:|^$sec$|:$sec$|:$sec:)/) {      return (\%classgroups,\%studentgroups);
                 $cache->{'sectionList'} .= ':'.$sec;  }
                                                                                      
   sub get_students_groups {
       my ($student,$enrollment_status,$classgroups) = @_;
       my @studentsgroups = ();
       if (ref($$classgroups{$student}{'active'}) eq 'HASH') {
           push(@studentsgroups,keys(%{$$classgroups{$student}{'active'}}));
       }
       if ($enrollment_status eq 'Any') {
           foreach my $status ('previous','future') {
               if (ref($$classgroups{$student}{$status}) eq 'HASH') {
                   push(@studentsgroups,keys(%{$$classgroups{$student}{$status}}));
             }              }
         } else {          }
             $cache->{'sectionList'} = $sec;      } else {
           if (ref($$classgroups{$student}{'aftercourse'}) eq 'HASH') {
               push(@studentsgroups,keys(%{$$classgroups{$student}{'aftercourse'}}));
         }          }
     }      }
       return @studentsgroups;
   }
   
     $cache->{'ClasslistTimestamp'}=time;  
     $cache->{'NamesOfStudents'}=join(':::',@names);  
   
     return @names;  # ----- END HELPER FUNCTIONS --------------------------------------------
 }  
   1;
   __END__
   
   
 =pod  =pod
   
 =item &ProcessStudentData()  =head1 NAME
   
 Takes the course data downloaded for a student in   Apache::loncoursedata
 &DownloadCourseInformation() and breaks it up into key value pairs  
 to be stored in the cached data.  The keys are comprised of the   
 $username:$domain:$keyFromCourseDatabase.  The student username:domain is  
 stored away signifying that the students information has been downloaded and   
 can be reused from cached data.  
   
 =over 4  =head1 SYNOPSIS
   
 Input: $cache, $courseData, $name  Set of functions that download and process student and course information.
   
 $cache: A hash pointer to store data  =head1 PACKAGES USED
   
 $courseData:  A hash pointer that points to the course data downloaded for a     Apache::lonnet
 student.    Apache::longroup
     Time::HiRes
     Apache::lonmysql
     LONCAPA
     Digest::MD5
    
   =head1 DOWNLOAD INFORMATION
   
 $name:  username:domain  This section contains all the functions that get data from other servers 
   and/or itself.
   
 Output: None  
   
 *NOTE:  There is no output, but an error message is stored away in the cache   
 data.  This is checked in &FormatStudentData().  The key username:domain:error   
 will only exist if an error occured.  The error is an error from   
 &DownloadCourseInformation().  
   
 =back  =head1 LOCAL DATA CACHING SUBROUTINES
   
 =cut  The local caching is done using MySQL.  There is no fall-back implementation
   if MySQL is not running.
   
 sub ProcessStudentData {  The programmers interface is to call &get_current_state() or some other
     my ($cache,$courseData,$name)=@_;  primary interface subroutine (described below).  The internals of this 
   storage system are documented here.
   
     if(!&CheckDateStampError($courseData, $cache, $name)) {  There are six tables used to store student performance data (the results of
         return;  a dumpcurrent).  Each of these tables is created in MySQL with a name of
     }  $courseid_*****, where ***** is 'symb', 'part', or whatever is appropriate 
   for the table.  The tables and their purposes are described below.
   
     # This little delete thing, should not be here.  Move some other  Some notes before we get started.
     # time though.  
     if(defined($cache->{$name.':keys'})) {  
  foreach (split(':::', $cache->{$name.':keys'})) {  
     delete $cache->{$name.':'.$_};  
  }  
         delete $cache->{$name.':keys'};  
     }  
   
     my %courseKeys;  Each table must have a PRIMARY KEY, which is a column or set of columns which
     # user name:domain was prepended earlier in DownloadCourseInformation  will serve to uniquely identify a row of data.  NULL is not allowed!
     foreach (keys %$courseData) {  
  my $currentKey = $_;  
  $currentKey =~ s/^$name//;  
  $courseKeys{$currentKey}++;  
         $cache->{$_}=$courseData->{$_};  
     }  
   
     $cache->{$name.':keys'} = join(':::', keys(%courseKeys));  INDEXes work best on integer data.
   
     return;  JOIN is used to combine data from many tables into one output.
 }  
   
 =pod  lonmysql.pm is used for some of the interface, specifically the table creation
   calls.  The inserts are done in bulk by directly calling the database handler.
   The SELECT ... JOIN statement used to retrieve the data does not have an
   interface in lonmysql.pm and I shudder at the thought of writing one.
   
 =item &ExtractStudentData()  =head2 Table Descriptions
   
 HISTORY: This function originally existed in every statistics module,  =over 4
 and performed different tasks, the had some overlap.  Due to the need  
 for the data from the different modules, they were combined into  =head2 Tables used to store meta information
 a single function.  
   The following tables hold data required to keep track of the current status
 This function now extracts all the necessary course data for a student  of a students data in the tables or to look up the students data in the tables.
 from what was downloaded from their homeserver.  There is some extra  
 time overhead compared to the ProcessStudentInformation function, but  
 it would have had to occurred at some point anyways.  This is now  
 typically called while downloading the data it will process.  It is  
 the brother function to ProcessStudentInformation.  
   
 =over 4  =over 4
   
 Input: $input, $output, $data, $name  =item C<$symb_table>
   
   The symb_table has two columns.  The first is a 'symb_id' and the second
   is the text name for the 'symb' (limited to 64k).  The 'symb_id' is generated
   automatically by MySQL so inserts should be done on this table with an
   empty first element.  This table has its PRIMARY KEY on the 'symb_id'.
   
   =item C<$part_table>
   
   The part_table has two columns.  The first is a 'part_id' and the second
   is the text name for the 'part' (limited to 100 characters).  The 'part_id' is
   generated automatically by MySQL so inserts should be done on this table with
   an empty first element.  This table has its PRIMARY KEY on the 'part' (100
   characters) and a KEY on 'part_id'.
   
 $input: A hash that contains the input data to be processed  =item C<$student_table>
   
 $output: A hash to contain the processed data  The student_table has 7 columns.  The first is a 'student_id' assigned by 
   MySQL.  The second is 'student' which is username:domain.  The third through
   fifth are 'section', 'status' (enrollment status), and 'classification' 
   (to be used in the future).  The sixth and seventh ('updatetime' and 
   'fullupdatetime') contain the time of last update and full update of student
   data.  This table has its PRIMARY KEY on the 'student_id' column and is indexed
   on 'student', 'section', and 'status'.
   
 $data: A hash containing the information on what is to be  =item C<$groupnames_table>
 processed and how (basically).  
   
 $name:  username:domain  The groupnames_table has 2 columns.  The first is a 'group_id' assigned by 
   MySQL.  The second is 'groupname' which is the name of the group in the course.
   
 The input is slightly different here, but is quite simple.  =item C<$students_groups_table>
 It is currently used where the $input, $output, and $data  
 can and are often the same hashes, but they do not need  
 to be.  
   
 Output: None  The students_groups_table has 2 columns.  The first is the 'student_id', and the 
   second is the 'group_id'. These two columns comprise the PRIMARY KEY for this 
   table, as an individual student may be affiliated with more than one group at
   any time. This table is indexed on both student_id and group_id.
   
 *NOTE:  There is no output, but an error message is stored away in the cache   =back 
 data.  This is checked in &FormatStudentData().  The key username:domain:error   
 will only exist if an error occured.  The error is an error from   =head2 Tables used to store current status data
 &DownloadCourseInformation().  
   The following tables store data only about the students current status on 
   a problem, meaning only the data related to the last attempt on a problem.
   
   =over 4
   
   =item C<$performance_table>
   
   The performance_table has 9 columns.  The first three are 'symb_id', 
   'student_id', and 'part_id'.  These comprise the PRIMARY KEY for this table
   and are directly related to the $symb_table, $student_table, and $part_table
   described above.  MySQL does better indexing on numeric items than text,
   so we use these three "index tables".  The remaining columns are
   'solved', 'tries', 'awarded', 'award', 'awarddetail', and 'timestamp'.
   These are either the MySQL type TINYTEXT or various integers ('tries' and 
   'timestamp').  This table has KEYs of 'student_id' and 'symb_id'.
   For use of this table, see the functions described below.
   
   =item C<$parameters_table>
   
   The parameters_table holds the data that does not fit neatly into the
   performance_table.  The parameters table has four columns: 'symb_id',
   'student_id', 'parameter', and 'value'.  'symb_id', 'student_id', and
   'parameter' comprise the PRIMARY KEY for this table.  'parameter' is 
   limited to 255 characters.  'value' is limited to 64k characters.
   
 =back  =back
   
 =cut  =head2 Tables used for storing historic data
   
 sub ExtractStudentData {  The following tables are used to store almost all of the transactions a student
     my ($input, $output, $data, $name)=@_;  has made on a homework problem.  See loncapa/docs/homework/datastorage for 
   specific information about each of the parameters stored.  
   
     if(!&CheckDateStampError($input, $data, $name)) {  =over 4
         return;  
     }  
   
     # This little delete thing, should not be here.  Move some other  =item C<$fulldump_response_table>
     # time though.  
     my %allkeys;  
     if(defined($output->{$name.':keys'})) {  
  foreach (split(':::', $output->{$name.':keys'})) {  
     delete $output->{$name.':'.$_};  
  }  
         delete $output->{$name.':keys'};  
     }  
   
     my ($username,$domain)=split(':',$name);  The response table holds data (documented in loncapa/docs/homework/datastorage)
   associated with a particular response id which is stored when a student 
   attempts a problem.  The following are the columns of the table, in order:
   'symb_id','part_id','response_id','student_id','transaction','tries',
   'awarddetail', 'response_specific', 'response_specific_value',
   'response_specific_2', 'response_specific_value_2', and 'submission
   (the text of the students submission).  The primary key is based on the
   first five columns listed above.
   
   =item C<$fulldump_part_table()>
   
   The part table holds data (documented in loncapa/docs/homework/datastorage)
   associated with a particular part id which is stored when a student attempts
   a problem.  The following are the columns of the table, in order:
   'symb_id','part_id','student_id','transaction','tries','award','awarded',
   and 'previous'.  The primary key is based on the first five columns listed 
   above.
   
   =item C<$fulldump_timestamp_table()>
   
   The timestamp table holds the timestamps of the transactions which are
   stored in $fulldump_response_table and $fulldump_part_table.  This data is
   about both the response and part data.  Columns: 'symb_id','student_id',
   'transaction', and 'timestamp'.  
   The primary key is based on the first 3 columns.
   
   =item C<$weight_table()>
   
   The weight table holds the weight for the problems used in the class.
   Whereas the weight of a problem can vary by section and student the data
   here is applied to the class as a whole.
   Columns: 'symb_id','part_id','response_id','weight'.
   
     my $Version;  =back
     my $problemsCorrect = 0;  
     my $totalProblems   = 0;  
     my $problemsSolved  = 0;  
     my $numberOfParts   = 0;  
     my $totalAwarded    = 0;  
     foreach my $sequence (split(':', $data->{'orderedSequences'})) {  
         foreach my $problemID (split(':', $data->{$sequence.':problems'})) {  
             my $problem = $data->{$problemID.':problem'};  
             my $LatestVersion = $input->{$name.':version:'.$problem};  
   
             # Output dashes for all the parts of this problem if there  
             # is no version information about the current problem.  
             $output->{$name.':'.$problemID.':NoVersion'} = 'false';  
             $allkeys{$name.':'.$problemID.':NoVersion'}++;  
             if(!$LatestVersion) {  
                 foreach my $part (split(/\:/,$data->{$sequence.':'.  
                                                       $problemID.  
                                                       ':parts'})) {  
                     $output->{$name.':'.$problemID.':'.$part.':tries'} = 0;  
                     $output->{$name.':'.$problemID.':'.$part.':awarded'} = 0;  
                     $output->{$name.':'.$problemID.':'.$part.':code'} = ' ';  
     $allkeys{$name.':'.$problemID.':'.$part.':tries'}++;  
     $allkeys{$name.':'.$problemID.':'.$part.':awarded'}++;  
     $allkeys{$name.':'.$problemID.':'.$part.':code'}++;  
                     $totalProblems++;  
                 }  
                 $output->{$name.':'.$problemID.':NoVersion'} = 'true';  
                 next;  
             }  
   
             my %partData=undef;  
             # Initialize part data, display skips correctly  
             # Skip refers to when a student made no submissions on that  
             # part/problem.  
             foreach my $part (split(/\:/,$data->{$sequence.':'.  
                                                  $problemID.  
                                                  ':parts'})) {  
                 $partData{$part.':tries'}=0;  
                 $partData{$part.':code'}=' ';  
                 $partData{$part.':awarded'}=0;  
                 $partData{$part.':timestamp'}=0;  
                 foreach my $response (split(':', $data->{$sequence.':'.  
                                                          $problemID.':'.  
                                                          $part.':responseIDs'})) {  
                     $partData{$part.':'.$response.':submission'}='';  
                 }  
             }  
   
             # Looping through all the versions of each part, starting with the  =head1 IMPORTANT SUBROUTINES
             # oldest version.  Basically, it gets the most recent   
             # set of grade data for each part.  
             my @submissions = ();  
     for(my $Version=1; $Version<=$LatestVersion; $Version++) {  
                 foreach my $part (split(/\:/,$data->{$sequence.':'.  
                                                      $problemID.  
                                                      ':parts'})) {  
   
                     if(!defined($input->{"$name:$Version:$problem".  
                                          ":resource.$part.solved"})) {  
                         # No grade for this submission, so skip  
                         next;  
                     }  
   
                     my $tries=0;  Here is a brief overview of the subroutines which are likely to be of 
                     my $code=' ';  interest:
                     my $awarded=0;  
   
                     $tries = $input->{$name.':'.$Version.':'.$problem.  
                                       ':resource.'.$part.'.tries'};  
                     $awarded = $input->{$name.':'.$Version.':'.$problem.  
                                         ':resource.'.$part.'.awarded'};  
   
                     $partData{$part.':awarded'}=($awarded) ? $awarded : 0;  
                     $partData{$part.':tries'}=($tries) ? $tries : 0;  
   
                     $partData{$part.':timestamp'}=$input->{$name.':'.$Version.':'.  
                                                            $problem.  
                                                            ':timestamp'};  
                     if(!$input->{$name.':'.$Version.':'.$problem.':resource.'.$part.  
                                  '.previous'}) {  
                         foreach my $response (split(':',  
                                                    $data->{$sequence.':'.  
                                                            $problemID.':'.  
                                                            $part.':responseIDs'})) {  
                             @submissions=($input->{$name.':'.$Version.':'.  
                                                    $problem.  
                                                    ':resource.'.$part.'.'.  
                                                    $response.'.submission'},  
                                           @submissions);  
                         }  
                     }  
   
                     my $val = $input->{$name.':'.$Version.':'.$problem.  =over 4
                                        ':resource.'.$part.'.solved'};  
                     if    ($val eq 'correct_by_student')   {$code = '*';}   
                     elsif ($val eq 'correct_by_override')  {$code = '+';}  
                     elsif ($val eq 'incorrect_attempted')  {$code = '.';}   
                     elsif ($val eq 'incorrect_by_override'){$code = '-';}  
                     elsif ($val eq 'excused')              {$code = 'x';}  
                     elsif ($val eq 'ungraded_attempted')   {$code = '#';}  
                     else                                   {$code = ' ';}  
                     $partData{$part.':code'}=$code;  
                 }  
             }  
   
             foreach my $part (split(/\:/,$data->{$sequence.':'.$problemID.  =item C<&get_current_state()>
                                                  ':parts'})) {  
                 $output->{$name.':'.$problemID.':'.$part.':wrong'} =   
                     $partData{$part.':tries'};  
  $allkeys{$name.':'.$problemID.':'.$part.':wrong'}++;  
   
                 if($partData{$part.':code'} eq '*') {  
                     $output->{$name.':'.$problemID.':'.$part.':wrong'}--;  
                     $problemsCorrect++;  
                 } elsif($partData{$part.':code'} eq '+') {  
                     $output->{$name.':'.$problemID.':'.$part.':wrong'}--;  
                     $problemsCorrect++;  
                 }  
   
                 $output->{$name.':'.$problemID.':'.$part.':tries'} =   programmers interface.
                     $partData{$part.':tries'};  
                 $output->{$name.':'.$problemID.':'.$part.':code'} =  
                     $partData{$part.':code'};  
                 $output->{$name.':'.$problemID.':'.$part.':awarded'} =  
                     $partData{$part.':awarded'};  
  $allkeys{$name.':'.$problemID.':'.$part.':tries'}++;  
  $allkeys{$name.':'.$problemID.':'.$part.':code'}++;  
  $allkeys{$name.':'.$problemID.':'.$part.':awarded'}++;  
   
                 $totalAwarded += $partData{$part.':awarded'};  
                 $output->{$name.':'.$problemID.':'.$part.':timestamp'} =  
                     $partData{$part.':timestamp'};  
  $allkeys{$name.':'.$problemID.':'.$part.':timestamp'}++;  
   
                 foreach my $response (split(':', $data->{$sequence.':'.  
                                                          $problemID.':'.  
                                                          $part.':responseIDs'})) {  
                     $output->{$name.':'.$problemID.':'.$part.':'.$response.  
                               ':submission'}=join(':::',@submissions);  
     $allkeys{$name.':'.$problemID.':'.$part.':'.$response.  
      ':submission'}++;  
                 }  
   
                 if($partData{$part.':code'} ne 'x') {  =item C<&init_dbs()>
                     $totalProblems++;  
                 }  
             }  
         }  
   
         $output->{$name.':'.$sequence.':problemsCorrect'} = $problemsCorrect;  table creation
  $allkeys{$name.':'.$sequence.':problemsCorrect'}++;  
         $problemsSolved += $problemsCorrect;  
  $problemsCorrect=0;  
     }  
   
     $output->{$name.':problemsSolved'} = $problemsSolved;  =item C<&update_student_data()>
     $output->{$name.':totalProblems'} = $totalProblems;  
     $output->{$name.':totalAwarded'} = $totalAwarded;  
     $allkeys{$name.':problemsSolved'}++;  
     $allkeys{$name.':totalProblems'}++;  
     $allkeys{$name.':totalAwarded'}++;  
   
     $output->{$name.':keys'} = join(':::', keys(%allkeys));  data storage calls
   
     return;  =item C<&get_student_data_from_performance_cache()>
 }  
   
 sub LoadDiscussion {  data retrieval
     my ($courseID)=@_;  
     my %Discuss=();  
     my %contrib=&Apache::lonnet::dump(  
                 $courseID,  
                 $ENV{'course.'.$courseID.'.domain'},  
                 $ENV{'course.'.$courseID.'.num'});  
     
     #my %contrib=&DownloadCourseInformation($name, $courseID, 0);  
   
     foreach my $temp(keys %contrib) {  
  if ($temp=~/^version/) {  
     my $ver=$contrib{$temp};  
     my ($dummy,$prb)=split(':',$temp);  
     for (my $idx=1; $idx<=$ver; $idx++ ) {  
  my $name=$contrib{"$idx:$prb:sendername"};  
  $Discuss{"$name:$prb"}=$idx;  
     }  
  }  
     }         
   
     return \%Discuss;  =back
 }  
   
 # ----- END PROCESSING FUNCTIONS ---------------------------------------  =head1 OTHER SUBROUTINES
   
 =pod  =over 4
   
 =head1 HELPER FUNCTIONS  =item C<&make_into_hash($values)>
   
 These are just a couple of functions do various odd and end   Returns a reference to a hash as described by $values.  $values is
 jobs.  There was also a couple of bulk functions added.  These are  assumed to be the result of 
 &DownloadStudentCourseData(), &DownloadStudentCourseDataSeparate(), and      join(':',map {&escape($_)} %orighash);
 &CheckForResidualDownload().  These functions now act as the interface  
 for downloading student course data.  The statistical modules should  
 no longer make the calls to dump and download and process etc.  They  
 make calls to these bulk functions to get their data.  
   
 =cut  This is a helper function for get_current_state.
   
 # ----- HELPER FUNCTIONS -----------------------------------------------  =item C<&init_dbs()>
   
 sub CheckDateStampError {  Input: course id
     my ($courseData, $cache, $name)=@_;  
     if($courseData->{$name.':UpToDate'} eq 'true') {  
         $cache->{$name.':lastDownloadTime'} =   
             $courseData->{$name.':lastDownloadTime'};  
         if($courseData->{$name.':lastDownloadTime'} eq 'Not downloaded') {  
             $cache->{$name.':updateTime'} = ' Not updated';  
         } else {  
             $cache->{$name.':updateTime'}=  
                 localtime($courseData->{$name.':lastDownloadTime'});  
         }  
         return 0;  
     }  
   
     $cache->{$name.':lastDownloadTime'}=$courseData->{$name.':lastDownloadTime'};  
     if($courseData->{$name.':lastDownloadTime'} eq 'Not downloaded') {  
         $cache->{$name.':updateTime'} = ' Not updated';  
     } else {  
         $cache->{$name.':updateTime'}=  
             localtime($courseData->{$name.':lastDownloadTime'});  
     }  
   
     if(defined($courseData->{$name.':error'})) {  Output: 0 on success, positive integer on error
         $cache->{$name.':error'}=$courseData->{$name.':error'};  
         return 0;  
     }  
   
     return 1;  This routine issues the calls to lonmysql to create the tables used to
 }  store student data.
   
 =pod  item C<&delete_caches()>
   
 =item &ProcessFullName()  This routine drops all the tables associated with a course from the 
   MySQL database.
   
 Takes lastname, generation, firstname, and middlename (or some partial  Input: course id (optional, determined by environment if omitted) 
 set of this data) and returns the full name version as a string.  Format  
 is Lastname generation, firstname middlename or a subset of this.  
   
 =cut  Returns: nothing
   
 sub ProcessFullName {  =item C<&get_part_id()>
     my ($lastname, $generation, $firstname, $middlename)=@_;  
     my $Str = '';  
   
     # Strip whitespace preceeding & following name components.  
     $lastname   =~ s/(\s+$|^\s+)//g;  
     $generation =~ s/(\s+$|^\s+)//g;  
     $firstname  =~ s/(\s+$|^\s+)//g;  
     $middlename =~ s/(\s+$|^\s+)//g;  
   
     if($lastname ne '') {  
  $Str .= $lastname;  
  $Str .= ' '.$generation if ($generation ne '');  
  $Str .= ',';  
         $Str .= ' '.$firstname  if ($firstname ne '');  
         $Str .= ' '.$middlename if ($middlename ne '');  
     } else {  
         $Str .= $firstname      if ($firstname ne '');  
         $Str .= ' '.$middlename if ($middlename ne '');  
         $Str .= ' '.$generation if ($generation ne '');  
     }  
   
     return $Str;  Get the MySQL id of a problem part string.
 }  
   
 =pod  Input: $part
   
 =item &TestCacheData()  Output: undef on error, integer $part_id on success.
   
 Determine if the cache database can be accessed with a tie.  It waits up to  =item C<&get_part()>
 ten seconds before returning failure.  This function exists to help with  
 the problems with stopping the data download.  When an abort occurs and the  
 user quickly presses a form button and httpd child is created.  This  
 child needs to wait for the other to finish (hopefully within ten seconds).  
   
 =over 4  Get the string describing a part from the MySQL id of the problem part.
   
 Input: $ChartDB  Input: $part_id
   
 $ChartDB: The name of the cache database to be opened  Output: undef on error, $part string on success.
   
 Output: -1, 0, 1  =item C<&get_symb_id()>
   
 -1: Could not tie database  Get the MySQL id of a symb.
  0: Use cached data  
  1: New cache database created, use that.  
   
 =back  Input: $symb
   
 =cut  Output: undef on error, integer $symb_id on success.
   
 sub TestCacheData {  =item C<&get_symb()>
     my ($ChartDB,$isRecalculate,$totalDelay)=@_;  
     my $isCached=-1;  
     my %testData;  
     my $tieTries=0;  
   
     if(!defined($totalDelay)) {  Get the symb associated with a MySQL symb_id.
         $totalDelay = 10;  
     }  
   
     if ((-e "$ChartDB") && (!$isRecalculate)) {  Input: $symb_id
  $isCached = 1;  
     } else {  
  $isCached = 0;  
     }  
   
     while($tieTries < $totalDelay) {  Output: undef on error, $symb on success.
         my $result=0;  
         if($isCached) {  
             $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_READER(),0640);  
         } else {  
             $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_NEWDB(),0640);  
         }  
         if($result) {  
             last;  
         }  
         $tieTries++;  
         sleep 1;  
     }  
     if($tieTries >= $totalDelay) {  
         return -1;  
     }  
   
     untie(%testData);  =item C<&get_student_id()>
   
     return $isCached;  Get the MySQL id of a student.
 }  
   
 sub DownloadStudentCourseData {  Input: $sname, $dom
     my ($students,$checkDate,$cacheDB,$extract,$status,$courseID,$r,$c)=@_;  
   
     my $title = 'LON-CAPA Statistics';  Output: undef on error, integer $student_id on success.
     my $heading = 'Download and Process Course Data';  
     my $studentCount = scalar(@$students);  
   
     my $WhatIWant;  =item C<&get_student()>
     $WhatIWant = '(^version:|';  
     $WhatIWant .= '^\d+:.+?:(resource\.\d+\.';  
     $WhatIWant .= '(solved|tries|previous|awarded|(\d+\.submission))\s*$';#'  
     $WhatIWant .= '|timestamp)';  
     $WhatIWant .= ')';  
 #    $WhatIWant = '.';  
   
     if($status eq 'true') {  Get student username:domain associated with the MySQL student_id.
         &Apache::lonhtmlcommon::Create_PrgWin($r, $title, $heading);  
     }  
   
     my $displayString;  Input: $student_id
     my $count=0;  
     foreach (@$students) {  
         my %cache;  
   
         if($c->aborted()) { return 'Aborted'; }  Output: undef on error, string $student (username:domain) on success.
   
         if($status eq 'true') {  =item C<&clear_internal_caches()>
             $count++;  
             my $displayString = $count.'/'.$studentCount.': '.$_;  
             &Apache::lonhtmlcommon::Update_PrgWin($displayString, $r);  
         }  
   
         my $downloadTime='Not downloaded';  Causes the internal caches used in get_student_id, get_student,
         my $needUpdate = 'false';  get_symb_id, get_symb, get_part_id, and get_part to be undef'd.
         if($checkDate eq 'true'  &&   
            tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {  
             $downloadTime = $cache{$_.':lastDownloadTime'};  
             $needUpdate = $cache{'ResourceUpdated'};  
             untie(%cache);  
         }  
   
         if($c->aborted()) { return 'Aborted'; }  Needs to be called before the first operation with the MySQL database
   for a given Apache request.
   
         if($needUpdate eq 'true') {  =item C<&update_full_student_data($sname,$sdom,$courseid)>
             $downloadTime = 'Not downloaded';  
  }  
  my $courseData =   
     &DownloadCourseInformation($_, $courseID, $downloadTime,   
        $WhatIWant);  
  if(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {  
     foreach my $key (keys(%$courseData)) {  
  if($key =~ /^(con_lost|error|no_such_host)/i) {  
     $courseData->{$_.':error'} = 'No course data for '.$_;  
     last;  
  }  
     }  
     if($extract eq 'true') {  
  &ExtractStudentData($courseData, \%cache, \%cache, $_);  
     } else {  
  &ProcessStudentData(\%cache, $courseData, $_);  
     }  
     untie(%cache);  
  } else {  
     next;  
  }  
     }  
     if($status eq 'true') { &Apache::lonhtmlcommon::Close_PrgWin($r); }  
   
     return 'OK';  Does a lonnet::dump on a student to populate the courses tables.
 }  
   
 sub DownloadStudentCourseDataSeparate {  Input: $sname, $sdom, $courseid
     my ($students,$checkDate,$cacheDB,$extract,$status,$courseID,$r,$c)=@_;  
     my $residualFile = $Apache::lonnet::tmpdir.$courseID.'DownloadFile.db';  
     my $title = 'LON-CAPA Statistics';  
     my $heading = 'Download Course Data';  
   
     my $WhatIWant;  Output: $returnstatus
     $WhatIWant = '(^version:|';  
     $WhatIWant .= '^\d+:.+?:(resource\.\d+\.';  
     $WhatIWant .= '(solved|tries|previous|awarded|(\d+\.submission))\s*$';#'  
     $WhatIWant .= '|timestamp)';  
     $WhatIWant .= ')';  
   
     &CheckForResidualDownload($cacheDB, 'true', 'true', $courseID, $r, $c);  $returnstatus is a string describing any errors that occurred.  'okay' is the
   default.
   
     my $studentCount = scalar(@$students);  This subroutine loads a students data using lonnet::dump and inserts
     if($status eq 'true') {  it into the MySQL database.  The inserts are done on three tables, 
         &Apache::lonhtmlcommon::Create_PrgWin($r, $title, $heading);  $fulldump_response_table, $fulldump_part_table, and $fulldump_timestamp_table.
     }  The INSERT calls are made directly by this subroutine, not through lonmysql 
     my $count=0;  because we do a 'bulk'insert which takes advantage of MySQLs non-SQL 
     my $displayString='';  compliant INSERT command to insert multiple rows at a time.  
     foreach (@$students) {  If anything has gone wrong during this process, $returnstatus is updated with 
         if($c->aborted()) {  a description of the error.
             return 'Aborted';  
         }  
   
         if($status eq 'true') {  Once the "fulldump" tables are updated, the tables used for chart and
             $count++;  spreadsheet (which hold only the current state of the student on their
             $displayString = $count.'/'.$studentCount.': '.$_;  homework, not historical data) are updated.  If all updates have occurred 
             &Apache::lonhtmlcommon::Update_PrgWin($displayString, $r);  successfully, $student_table is updated to reflect the time of the update.
         }  
   
         my %cache;  Notice we do not insert the data and immediately query it.  This means it
         my $downloadTime='Not downloaded';  is possible for there to be data returned this first time that is not 
         my $needUpdate = 'false';  available the second time.  CYA.
         if($checkDate eq 'true'  &&   
            tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {  
             $downloadTime = $cache{$_.':lastDownloadTime'};  
             $needUpdate = $cache{'ResourceUpdated'};  
             untie(%cache);  
         }  
   
         if($c->aborted()) {  
             return 'Aborted';  
         }  
   
         if($needUpdate eq 'true') {  =item C<&update_student_data()>
             $downloadTime = 'Not downloaded';  
  }  
   
         my $error = 0;  Input: $sname, $sdom, $courseid
         my $courseData =   
             &DownloadCourseInformation($_, $courseID, $downloadTime,  
                                        $WhatIWant);  
         my %downloadData;  
         unless(tie(%downloadData,'GDBM_File',$residualFile,  
                    &GDBM_WRCREAT(),0640)) {  
             return 'Failed to tie temporary download hash.';  
         }  
         foreach my $key (keys(%$courseData)) {  
             $downloadData{$key} = $courseData->{$key};  
             if($key =~ /^(con_lost|error|no_such_host)/i) {  
                 $error = 1;  
                 last;  
             }  
         }  
         if($error) {  
             foreach my $deleteKey (keys(%$courseData)) {  
                 delete $downloadData{$deleteKey};  
             }  
             $downloadData{$_.':error'} = 'No course data for '.$_;  
         }  
         untie(%downloadData);  
     }  
     if($status eq 'true') { &Apache::lonhtmlcommon::Close_PrgWin($r); }  
   
     return &CheckForResidualDownload($cacheDB, 'true', 'true',   Output: $returnstatus, \%student_data
                                      $courseID, $r, $c);  
 }  
   
 sub CheckForResidualDownload {  $returnstatus is a string describing any errors that occurred.  'okay' is the
     my ($cacheDB,$extract,$status,$courseID,$r,$c)=@_;  default.
   \%student_data is the data returned by a call to lonnet::currentdump.
   
     my $residualFile = $Apache::lonnet::tmpdir.$courseID.'DownloadFile.db';  This subroutine loads a students data using lonnet::currentdump and inserts
     if(!-e $residualFile) {  it into the MySQL database.  The inserts are done on two tables, 
         return 'OK';  $performance_table and $parameters_table.  $parameters_table holds the data 
     }  that is not included in $performance_table.  See the description of 
   $performance_table elsewhere in this file.  The INSERT calls are made
   directly by this subroutine, not through lonmysql because we do a 'bulk'
   insert which takes advantage of MySQLs non-SQL compliant INSERT command to 
   insert multiple rows at a time.  If anything has gone wrong during this
   process, $returnstatus is updated with a description of the error and
   \%student_data is returned.  
   
     my %downloadData;  Notice we do not insert the data and immediately query it.  This means it
     my %cache;  is possible for there to be data returned this first time that is not 
     unless(tie(%downloadData,'GDBM_File',$residualFile,&GDBM_READER(),0640)) {  available the second time.  CYA.
         return 'Can not tie database for check for residual download: tempDB';  
     }  
     unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {  
         untie(%downloadData);  
         return 'Can not tie database for check for residual download: cacheDB';  
     }  
   
     my @students=();  =item &ensure_tables_are_set_up($courseid)
     my %checkStudent;  
     my $key;  
     while(($key, undef) = each %downloadData) {  
         my @temp = split(':', $key);  
         my $student = $temp[0].':'.$temp[1];  
         if(!defined($checkStudent{$student})) {  
             $checkStudent{$student}++;  
             push(@students, $student);  
         }  
     }  
   
     my $heading = 'Process Course Data';  Checks to be sure the MySQL tables for the given class are set up.
     my $title = 'LON-CAPA Statistics';  If $courseid is omitted it will be obtained from the environment.
     my $studentCount = scalar(@students);  
     if($status eq 'true') {  
         &Apache::lonhtmlcommon::Create_PrgWin($r, $title, $heading);  
     }  
   
     my $count=1;  Returns nothing on success and 'error' on failure
     foreach my $name (@students) {  
         last if($c->aborted());  
   
         if($status eq 'true') {  
             my $displayString = $count.'/'.$studentCount.': '.$name;  
             &Apache::lonhtmlcommon::Update_PrgWin($displayString, $r);  
         }  
   
         if($extract eq 'true') {  =item C<&ensure_current_data()>
             &ExtractStudentData(\%downloadData, \%cache, \%cache, $name);  
         } else {  
             &ProcessStudentData(\%cache, \%downloadData, $name);  
         }  
         $count++;  
     }  
   
     if($status eq 'true') { &Apache::lonhtmlcommon::Close_PrgWin($r); }  Input: $sname, $sdom, $courseid
   
     untie(%cache);  Output: $status, $data
     untie(%downloadData);  
   
     if(!$c->aborted()) {  This routine ensures the data for a given student is up to date.
         my @files = ($residualFile);  The $student_table is queried to determine the time of the last update.  
         unlink(@files);  If the students data is out of date, &update_student_data() is called.  
     }  The return values from the call to &update_student_data() are returned.
   
     return 'OK';  =item C<&ensure_current_full_data($sname,$sdom,$courseid)>
 }  
   
   Input: $sname, $sdom, $courseid
   
 ################################################  Output: $status
 ################################################  
   
 =pod  This routine ensures the fulldata (the data from a lonnet::dump, not a
   lonnet::currentdump) for a given student is up to date.
   The $student_table is queried to determine the time of the last update.  
   If the students fulldata is out of date, &update_full_student_data() is
   called.  
   
 =item &make_into_hash($values);  The return value from the call to &update_full_student_data() is returned.
   
 Returns a reference to a hash as described by $values.  $values is  =item C<&get_student_data_from_performance_cache()>
 assumed to be the result of   
     join(':',map {&Apache::lonnet::escape($_)} %orighash;  
   
 This is a helper function for get_current_state.  Input: $sname, $sdom, $symb, $courseid
   
 =cut  Output: hash reference containing the data for the given student.
   If $symb is undef, all the students data is returned.
   
 ################################################  This routine is the heart of the local caching system.  See the description
 ################################################  of $performance_table, $symb_table, $student_table, and $part_table.  The
 sub make_into_hash {  main task is building the MySQL request.  The tables appear in the request
     my $values = shift;  in the order in which they should be parsed by MySQL.  When searching
     my %tmp = map { &Apache::lonnet::unescape($_); }  on a student the $student_table is used to locate the 'student_id'.  All
                                            split(':',$values);  rows in $performance_table which have a matching 'student_id' are returned,
     return \%tmp;  with data from $part_table and $symb_table which match the entries in
 }  $performance_table, 'part_id' and 'symb_id'.  When searching on a symb,
   the $symb_table is processed first, with matching rows grabbed from 
   $performance_table and filled in from $part_table and $student_table in
   that order.  
   
   Running 'EXPLAIN ' on the 'SELECT' statements generated can be quite 
   interesting, especially if you play with the order the tables are listed.  
   
 ################################################  
 ################################################  
   
 =pod  =item C<&get_current_state()>
   
 =item &get_current_state($sname,$sdom,$symb,$courseid);  Input: $sname,$sdom,$symb,$courseid
   
   Output: Described below
   
 Retrieve the current status of a students performance.  $sname and  Retrieve the current status of a students performance.  $sname and
 $sdom are the only required parameters.  If $symb is undef the results  $sdom are the only required parameters.  If $symb is undef the results
Line 1553  If $symb is specified, a hash of Line 3155  If $symb is specified, a hash of
 )  )
 is returned.  is returned.
   
 If no data is found for $symb, or if the student has not performance data,  If no data is found for $symb, or if the student has no performance data,
 an empty list is returned.  an empty list is returned.
   
 =cut  =item C<&get_problem_statistics()>
   
 ################################################  Gather data on a given problem.  The database is assumed to be 
 ################################################  populated and all local caching variables are assumed to be set
 sub get_current_state {  properly.  This means you need to call &ensure_current_data for
     my ($sname,$sdom,$symb,$courseid,$forcedownload)=@_;  the students you are concerned with prior to calling this routine.
     return () if (! defined($sname) || ! defined($sdom));  
     #  
     $courseid = $ENV{'request.course.id'} if (! defined($courseid));  
     #  
     my $cachefilename = $Apache::lonnet::tmpdir.$ENV{'user.name'}.'_'.  
                                                 $ENV{'user.domain'}.'_'.  
                                                 $courseid.'_student_data.db';  
     my %cache;  
     #  
     my %student_data; # return values go here  
     #  
     my $updatetime = 0;  
     my $key = &Apache::lonnet::escape($sname).':'.  
               &Apache::lonnet::escape($sdom).':';  
     # Open the cache file  
     if (tie(%cache,'GDBM_File',$cachefilename,&GDBM_READER(),0640)) {  
         if (exists($cache{$key.'time'})) {  
             $updatetime = $cache{$key.'time'};  
 #            &Apache::lonnet::logthis('got updatetime of '.$updatetime);  
         }  
         untie(%cache);  
     }  
     # timestamp/devalidation   
     my $modifiedtime = 1;  
     # Take whatever steps are neccessary at this point to give $modifiedtime a  
     # new value  
     #  
     if (($updatetime < $modifiedtime) ||   
         (defined($forcedownload) && $forcedownload)) {  
 #        &Apache::lonnet::logthis("loading data");  
         # Get all the students current data  
         my $time_of_retrieval = time;  
         my @tmp = &Apache::lonnet::currentdump($courseid,$sdom,$sname);  
         if ((scalar(@tmp) > 0) && ($tmp[0] =~ /^error:/)) {  
             &Apache::lonnet::logthis('error getting data for '.  
                                      $sname.':'.$sdom.' in course '.$courseid.  
                                      ':'.$tmp[0]);  
             return ();  
         }  
         %student_data = @tmp;  
         #  
         # Store away the data  
         #  
         # The cache structure is colon deliminated.    
         # $uname:$udom:time  => timestamp  
         # $uname:$udom:$symb => $parm1:$val1:$parm2:$val2 ...  
         #  
         # BEWARE: The colons are NOT escaped so can search with escaped   
         #         keys instead of unescaping every key.  
         #  
         if (tie(%cache,'GDBM_File',$cachefilename,&GDBM_WRCREAT(),0640)) {  
 #            &Apache::lonnet::logthis("writing data");  
             while (my ($current_symb,$param_hash) = each(%student_data)) {  
                 my @Parameters = %{$param_hash};  
                 my $value = join(':',map { &Apache::lonnet::escape($_); }   
                                  @Parameters);  
                 # Store away the values  
                 $cache{$key.&Apache::lonnet::escape($current_symb)}=$value;  
             }  
             $cache{$key.'time'}=$time_of_retrieval;  
             untie(%cache);  
         }  
     } else {  
         &Apache::lonnet::logthis('retrieving cached data ');  
         if (tie(%cache,'GDBM_File',$cachefilename,&GDBM_READER(),0640)) {  
             if (defined($symb)) {  
                 my  $searchkey = $key.&Apache::lonnet::escape($symb);  
                 if (exists($cache{$searchkey})) {  
                     $student_data{$symb} = &make_into_hash($cache{$searchkey});  
                 }  
             } else {  
                 my $searchkey = '^'.$key.'(.*)$';#'  
                 while (my ($testkey,$params)=each(%cache)) {  
                     if ($testkey =~ /$searchkey/) { # \Q \E?  May be necc.  
                         my $tmpsymb = $1;  
                         next if ($tmpsymb =~ 'time');  
 #                        &Apache::lonnet::logthis('found '.$tmpsymb.':');  
                         $student_data{&Apache::lonnet::unescape($tmpsymb)} =   
                             &make_into_hash($params);  
                     }  
                 }  
             }  
             untie(%cache);  
         }  
     }  
     if (! defined($symb)) {  
 #        &Apache::lonnet::logthis("returning all data");  
         return %student_data;  
     } elsif (exists($student_data{$symb})) {  
 #        &Apache::lonnet::logthis("returning data for symb=".$symb);  
         return %{$student_data{$symb}};  
     } else {  
         return ();  
     }  
 }  
   
 ################################################  Inputs: $Sections, Groups, $status, $symb, $part, $courseid, $starttime,
 ################################################          $endtime
   
 =pod  =over 4
   
   =item $Sections Array ref containing section names for students.  
   'all' is allowed to be the first (and only) item in the array.
   
   =item $Groups Array ref containing group names for students.
   'all' is allowed to be the first (and only) item in the array.
   
   =item $status String describing the status of students
   
   =item $symb is the symb for the problem.
   
   =item $part is the part id you need statistics for
   
   =item $courseid is the course id, of course!
   
   =item $starttime and $endtime are unix times which to use to limit
   the statistical data.
   
   =back
   
   Outputs: See the code for up to date information.  A hash reference is
   returned.  The hash has the following keys defined:
   
   =over 4
   
   =item * num_students 
   
   The number of students attempting the problem
         
   =item tries 
   
   The total number of tries for the students
         
   =item max_tries 
   
   The maximum number of tries taken
         
   =item mean_tries 
   
   The average number of tries
         
   =item num_solved T
   
   he number of students able to solve the problem
         
   =item num_override 
   
   The number of students whose answer is 'correct_by_override'
         
   =item deg_of_diff 
   
   The degree of difficulty of the problem
         
   =item std_tries 
   
   The standard deviation of the number of tries
         
   =item skew_tries 
   
   The skew of the number of tries
   
   =item per_wrong 
   
   The number of students attempting the problem who were not
   able to answer it correctly.
   
   =back
   
   =item C<&populate_weight_table()>
   
   =item C<&limit_by_start_end_times()>
   
   Build SQL WHERE condition which limits the data collected by the start
   and end times provided
   
   Inputs: $starttime, $endtime, $table
   
   Returns: $time_limits
   
   
   =item C<&limit_by_section_and_status()C>
   
   Build SQL WHERE condition which limits the data collected by section and
   student status.
   
   Inputs: $Sections (array ref)
       $enrollment (string: 'any', 'expired', 'active')
       $tablename The name of the table that holds the student data
   
   Returns: $student_requirements,$enrollment_requirements
   
   =item C<&limit_by_group()>
                                                                                  
   Build SQL LEFT JOIN statement to include students_groups and groupnames tables and SQL WHERE condition which limits the data collected by group.
                                                                                  
   Inputs: $Groups (array ref)
       $stutable   The name of the table which holds the student data.
       $grptable   The name of the table which maps group_id to groupname.
       $stugrptab  The name of the table which holds student group affiliations.   
   Returns: $groups_join,$group_limits
      $groups_join  JOIN part of SQL statement (to include group related tables) 
      $group_limits SQL WHERE condition limiting to requested groups
   
   =item C<rank_students_by_scores_on_resources()>
   
   Inputs: 
       $resources: array ref of hash ref.  Each hash ref needs key 'symb'.
       $Sections: array ref of sections to include,
       $Groups: array ref of groups to include.
       $enrollment: string,
       $courseid (may be omitted)
       $starttime (may be omitted)
       $endtime (may be omitted)
       $has_award_for (may be omitted)
   
   Returns; An array of arrays.  The sub arrays contain a student name and
   their score on the resources. $starttime and $endtime constrain the
   list to awards obtained during the given time limits. $has_score_on
   constrains the list to those students who at least attempted the
   resource identified by the given symb, which is used to filter out
   such students for statistics that would be adversely affected by such
   students.
   
   =item C<&get_sum_of_scores>
   
   Inputs: $resource (hash ref, needs {'symb'} key),
   $part, (the part id),
   $students (array ref, contents of array are scalars holding 'sname:sdom'),
   $courseid
   
   Returns: the sum of the score on the problem part over the students and the
      maximum possible value for the sum (taken from the weight table).
    
   
   =item C<&score_stats()>
   
   Inputs: $Sections, $enrollment, $symbs, $starttime,
           $endtime, $courseid
   
   $Sections, $enrollment, $starttime, $endtime, and $courseid are the same as 
   elsewhere in this module.  
   $symbs is an array ref of symbs
   
   Returns: minimum, maximum, mean, s.d., number of students, and maximum
     possible of student scores on the given resources
   
   =item C<&count_stats()>
   
   Inputs: $Sections, $Groups, $enrollment, $symbs, $starttime,
           $endtime, $courseid
   
   $Sections, $Groups $enrollment, $starttime, $endtime, and $courseid are the 
   same as elsewhere in this module.  
   $symbs is an array ref of symbs
   
   Returns: minimum, maximum, mean, s.d., and number of students
     of the number of items correct on the given resources
   
   =item C<get_student_data()>
   
   =item C<&get_student_scores($Sections,$Groups,$Symbs,$enrollment,$courseid)>
   
   =item C<&setup_table_names()>
   
   input: course id
   
   output: none
   
   =back
   
   =head3 End of Local Data Caching Subroutines
   
   =head3 Classlist Subroutines
   
   =over
   
 =item &get_classlist();  =item &get_classlist();
   
Line 1669  Retrieve the classist of a given class o Line 3351  Retrieve the classist of a given class o
 information is returned from the classlist.db file and, if needed,  information is returned from the classlist.db file and, if needed,
 from the students environment.  from the students environment.
   
 Optional arguments are $cid, $cdom, and $cnum (course id, course domain,  Optional arguments are $cdom, and $cnum (course domain,
 and course number, respectively).  Any omitted arguments will be taken   and course number, respectively).  If either is ommitted the course
 from the current environment ($ENV{'request.course.id'},  will be taken from the current environment ($env{'request.course.id'},
 $ENV{'course.'.$cid.'.domain'}, and $ENV{'course.'.$cid.'.num'}).  $env{'course.'.$cid.'.domain'}, and $env{'course.'.$cid.'.num'}).
   
 Returns a reference to a hash which contains:  Returns a reference to a hash which contains:
  keys    '$sname:$sdom'   keys    '$sname:$sdom'
  values  [$end,$start,$id,$section,$fullname]   values  [$sdom,$sname,$end,$start,$id,$section,$fullname,$status,$type,
             $lockedtype,$credits,$instsec]
 =cut  
   
 ################################################  
 ################################################  
   
 sub get_classlist {  The constant values CL_SDOM, CL_SNAME, CL_END, etc. can be used
     my ($cid,$cdom,$cnum) = @_;  as indices into the returned list to future-proof clients against
     $cid = $cid || $ENV{'request.course.id'};  changes in the list order.
     $cdom = $cdom || $ENV{'course.'.$cid.'.domain'};  
     $cnum = $cnum || $ENV{'course.'.$cid.'.num'};  
    my $now = time;  
     #  
     my %classlist=&Apache::lonnet::dump('classlist',$cdom,$cnum);  
     while (my ($student,$info) = each(%classlist)) {  
         return undef if ($student =~ /^(con_lost|error|no_such_host)/i);  
         my ($sname,$sdom) = split(/:/,$student);  
         my @Values = split(/:/,$info);  
         my ($end,$start,$id,$section,$fullname);  
         if (@Values > 2) {  
             ($end,$start,$id,$section,$fullname) = @Values;  
         } else { # We have to get the data ourselves  
             ($end,$start) = @Values;  
             $section = &Apache::lonnet::getsection($sdom,$sname,$cid);  
             my %info=&Apache::lonnet::get('environment',  
                                           ['firstname','middlename',  
                                            'lastname','generation','id'],  
                                           $sdom, $sname);  
             my ($tmp) = keys(%info);  
             if ($tmp =~/^(con_lost|error|no_such_host)/i) {  
                 $fullname = 'not available';  
                 $id = 'not available';  
                 &Apache::lonnet::logthis('unable to retrieve environment '.  
                                          'for '.$sname.':'.$sdom);  
             } else {  
                 $fullname = &ProcessFullName(@info{qw/lastname generation   
                                                        firstname middlename/});  
                 $id = $info{'id'};  
             }  
             # Update the classlist with this students information  
             if ($fullname ne 'not available') {  
                 my $enrolldata = join(':',$end,$start,$id,$section,$fullname);  
                 my $reply=&Apache::lonnet::cput('classlist',  
                                                 {$student => $enrolldata},  
                                                 $cdom,$cnum);  
                 if ($reply !~ /^(ok|delayed)/) {  
                     &Apache::lonnet::logthis('Unable to update classlist for '.  
                                              'student '.$sname.':'.$sdom.  
                                              ' error:'.$reply);  
                 }  
             }  
         }  
         my $status='Expired';  
         if(((!$end) || $now < $end) && ((!$start) || ($now > $start))) {  
             $status='Active';  
         }  
         $classlist{$student} =   
             [$sdom,$sname,$end,$start,$id,$section,$fullname,$status];  
     }  
     if (wantarray()) {  
         return (\%classlist,['domain','username','end','start','id',  
                              'section','fullname','status']);  
     } else {  
         return \%classlist;  
     }  
 }  
   
 # ----- END HELPER FUNCTIONS --------------------------------------------  =back
   
 1;  =cut
 __END__  
   
   

Removed from v.1.49  
changed lines
  Added in v.1.205


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