Diff for /loncom/interface/lonnavmaps.pm between versions 1.53 and 1.98

version 1.53, 2002/09/24 03:48:18 version 1.98, 2002/11/08 18:35:37
Line 1 Line 1
   
 # The LearningOnline Network with CAPA  # The LearningOnline Network with CAPA
 # Navigate Maps Handler  # Navigate Maps Handler
 #  #
Line 44  use strict; Line 45  use strict;
 use Apache::Constants qw(:common :http);  use Apache::Constants qw(:common :http);
 use Apache::lonnet();  use Apache::lonnet();
 use Apache::loncommon();  use Apache::loncommon();
 use HTML::TokeParser;  
 use GDBM_File;  use GDBM_File;
   use POSIX qw (floor strftime);
   
 # -------------------------------------------------------------- Module Globals  # -------------------------------------------------------------- Module Globals
 my %hash;  my %hash;
Line 124  sub parmval { Line 125  sub parmval {
     my $courselevelm=$usercourseprefix.'.'.$mapparm;      my $courselevelm=$usercourseprefix.'.'.$mapparm;
   
 # ---------------------------------------------------------- first, check user  # ---------------------------------------------------------- first, check user
     if ($uname) {      if (defined($uname)) {
         if ($useropt{$courselevelr}) { return $useropt{$courselevelr}; }          if (defined($useropt{$courselevelr})) { return $useropt{$courselevelr}; }
         if ($useropt{$courselevelm}) { return $useropt{$courselevelm}; }          if (defined($useropt{$courselevelm})) { return $useropt{$courselevelm}; }
         if ($useropt{$courselevel}) { return $useropt{$courselevel}; }          if (defined($useropt{$courselevel})) { return $useropt{$courselevel}; }
     }      }
   
 # ------------------------------------------------------- second, check course  # ------------------------------------------------------- second, check course
     if ($csec) {      if (defined($csec)) {
         if ($courseopt{$seclevelr}) { return $courseopt{$seclevelr}; }          if (defined($courseopt{$seclevelr})) { return $courseopt{$seclevelr}; }
         if ($courseopt{$seclevelm}) { return $courseopt{$seclevelm}; }          if (defined($courseopt{$seclevelm})) { return $courseopt{$seclevelm}; }
         if ($courseopt{$seclevel}) { return $courseopt{$seclevel}; }          if (defined($courseopt{$seclevel})) { return $courseopt{$seclevel}; }
     }      }
   
     if ($courseopt{$courselevelr}) { return $courseopt{$courselevelr}; }      if (defined($courseopt{$courselevelr})) { return $courseopt{$courselevelr}; }
     if ($courseopt{$courselevelm}) { return $courseopt{$courselevelm}; }      if (defined($courseopt{$courselevelm})) { return $courseopt{$courselevelm}; }
     if ($courseopt{$courselevel}) { return $courseopt{$courselevel}; }      if (defined($courseopt{$courselevel})) { return $courseopt{$courselevel}; }
   
 # ----------------------------------------------------- third, check map parms  # ----------------------------------------------------- third, check map parms
   
     my $thisparm=$parmhash{$symbparm};      my $thisparm=$parmhash{$symbparm};
     if ($thisparm) { return $thisparm; }      if (defined($thisparm)) { return $thisparm; }
   
 # ----------------------------------------------------- fourth , check default  # ----------------------------------------------------- fourth , check default
   
     my $default=&Apache::lonnet::metadata($fn,$rwhat.'.default');      my $default=&Apache::lonnet::metadata($fn,$rwhat.'.default');
     if ($default) { return $default}      if (defined($default)) { return $default}
   
 # --------------------------------------------------- fifth , cascade up parts  # --------------------------------------------------- fifth , cascade up parts
   
Line 159  sub parmval { Line 160  sub parmval {
         my ($part,$id)=split(/\_/,$space);          my ($part,$id)=split(/\_/,$space);
         if ($id) {          if ($id) {
             my $partgeneral=&parmval($part.".$qualifier",$symb);              my $partgeneral=&parmval($part.".$qualifier",$symb);
             if ($partgeneral) { return $partgeneral; }              if (defined($partgeneral)) { return $partgeneral; }
         } else {          } else {
             my $resourcegeneral=&parmval("0.$qualifier",$symb);              my $resourcegeneral=&parmval("0.$qualifier",$symb);
             if ($resourcegeneral) { return $resourcegeneral; }              if (defined($resourcegeneral)) { return $resourcegeneral; }
         }          }
     }      }
     return '';      return '';
Line 819  sub new_handle { Line 820  sub new_handle {
     &Apache::loncommon::no_cache($r);      &Apache::loncommon::no_cache($r);
     $r->send_http_header;      $r->send_http_header;
   
       # Create the nav map the nav map
       my $navmap = Apache::lonnavmaps::navmap->new(
                           $ENV{"request.course.fn"}.".db",
                           $ENV{"request.course.fn"}."_parms.db", 1, 1);
   
   
       if (!defined($navmap)) {
           my $requrl = $r->uri;
           $ENV{'user.error.msg'} = "$requrl:bre:0:0:Course not initialized";
           return HTTP_NOT_ACCEPTABLE;
       }
   
     # Header      # Header
     $r->print(&Apache::loncommon::bodytag('Navigate Course Map','',      $r->print(&Apache::loncommon::bodytag('Navigate Course Map','',
                                           ''));                                            ''));
     # Initialize the nav map      $r->print('<script>window.focus();</script>');
     my $navmap = Apache::lonnavmaps::navmap->new(      my $desc=$ENV{'course.'.$ENV{'request.course.id'}.'.description'};
                         $ENV{"request.course.fn"}.".db",      $r->print('<table border="0" cellpadding="2" cellspacing="0">');
                         $ENV{"request.course.fn"}."_parms.db", 1);      my $date=localtime;
       $r->print('<tr><td align="right" valign="bottom">Key:&nbsp;&nbsp;</td>');
       if ($navmap->{LAST_CHECK}) {
           $r->print('<td align="center" valign="bottom">&nbsp;&nbsp;'.
                     '<img src="/adm/lonMisc/chat.gif"> New discussion since '.
                     strftime("%A, %b %e at %I:%M %P", localtime($navmap->{LAST_CHECK})).
                     '</td><td align="center" valign="bottom">&nbsp;&nbsp;'.
                     '<img src="/adm/lonMisc/feedback.gif"> New message (click to open)<p>'.
                     '</td>'); 
       } else {
           $r->print('<td align="center" valign="bottom">&nbsp;&nbsp;'.
                     '<img src="/adm/lonMisc/chat.gif"> Discussions</td><td align="center" valign="bottom">'.
                     '&nbsp;&nbsp;<img src="/adm/lonMisc/feedback.gif"> New message (click to open)'.
                     '</td>'); 
       }
       $r->print('</tr></table>');
       my $condition = 0;
       if ($ENV{'form.condition'}) {
           $condition = 1;
       }
   
       if ($condition) {
           $r->print('<a href="navmaps?condition=0&filter=">Close All Folders</a>');
       } else {
           $r->print('<a href="navmaps?condition=1&filter=">Open All Folders</a>');
       }
   
       $r->print('<br>&nbsp;');
       $r->rflush();
   
       # Now that we've displayed some stuff to the user, init the navmap
       $navmap->init();
   
       # Check that it's defined
       if (!($navmap->courseMapDefined())) {
           $r->print('<font size="+2" color="red">Coursemap undefined.</font>' .
                     '</body></html>');
           return OK;
       }
   
     # Grab a resource object so we have access to the constants; this      # Grab a resource object so we have access to the constants; this
     # is technically not proper, but should be harmless      # is technically not proper, but should be harmless
Line 833  sub new_handle { Line 884  sub new_handle {
   
     # Defines a status->color mapping, null string means don't color      # Defines a status->color mapping, null string means don't color
     my %colormap =       my %colormap = 
     ( $res->NETWORK_FAILURE    => '',      ( $res->NETWORK_FAILURE        => '',
       $res->CORRECT            => '#BBFFBB',        $res->CORRECT                => '',
       $res->EXCUSED            => '#BBBBFF',        $res->EXCUSED                => '#BBBBFF',
       $res->PAST_DUE           => '#FFAA00',        $res->PAST_DUE_ANSWER_LATER  => '',
       $res->ANSWER_OPEN        => '#FF00AA',        $res->PAST_DUE_NO_ANSWER     => '',
       $res->OPEN_LATER         => '',        $res->ANSWER_OPEN            => '#CCFFCC',
       $res->TRIES_LEFT         => '#FFFF00',        $res->OPEN_LATER             => '',
       $res->INCORRECT          => '#FFAA00',        $res->TRIES_LEFT             => '',
       $res->OPEN               => '#FFFF88',        $res->INCORRECT              => '',
       $res->NOTHING_SET        => ''        );        $res->OPEN                   => '',
         $res->NOTHING_SET            => ''        );
     if (!defined($navmap)) {      # And a special case in the nav map; what to do when the assignment
         my $requrl = $r->uri;      # is not yet done and due in less then 24 hours
         $ENV{'user.error.msg'} = "$requrl:bre:0:0:Course not initialized";      my $hurryUpColor = "#FF0000";
         return HTTP_NOT_ACCEPTABLE;  
     }      my %statusIconMap = 
           ( $res->NETWORK_FAILURE    => '',
             $res->NOTHING_SET        => '',
             $res->CORRECT            => 'navmap.correct.gif',
             $res->EXCUSED            => 'navmap.correct.gif',
             $res->PAST_DUE_NO_ANSWER => 'navmap.wrong.gif',
             $res->PAST_DUE_ANSWER_LATER => 'navmap.wrong.gif',
             $res->ANSWER_OPEN        => 'navmap.wrong.gif',
             $res->OPEN_LATER         => '',
             $res->TRIES_LEFT         => 'navmap.open.gif',
             $res->INCORRECT          => 'navmap.wrong.gif',
             $res->OPEN               => 'navmap.open.gif',
             $res->ATTEMPTED          => 'navmap.open.gif' );
   
       my %iconAltTags = 
           ( 'navmap.correct.gif' => 'Correct',
             'navmap.wrong.gif'   => 'Incorrect',
             'navmap.open.gif'    => 'Open' );
   
       my %condenseStatuses =
           ( $res->NETWORK_FAILURE    => 1,
             $res->NOTHING_SET        => 1,
             $res->CORRECT            => 1 );
   
     my %filterHash;      my %filterHash;
     # Figure out what we're not displaying      # Figure out what we're not displaying
Line 858  sub new_handle { Line 931  sub new_handle {
         }          }
     }      }
   
       # Is this a new-style course? If so, we want to suppress showing the top-level
       # maps in their own folders, in favor of "inlining" them.
       my $topResource = $navmap->getById("0.0");
       my $inlineTopLevelMaps = $topResource->src() =~ m|^/uploaded/.*default\.sequence$|;
   
       my $currenturl = $ENV{'form.postdata'};
       $currenturl=~s/^http\:\/\///;
       $currenturl=~s/^[^\/]+//;
       # alreadyHere allows us to only open the maps necessary to view
       # the current location once, while at the same time remembering
       # the current location. Without that check, the user would never
       # be able to close those maps; the user would close it, and the
       # currenturl scan would re-open it.
       my $queryAdd = "postdata=" . &Apache::lonnet::escape($currenturl) .
           "&alreadyHere=1";
   
     # Begin the HTML table      # Begin the HTML table
     # two columns: the title/icon on the left, the info on the right      # four cols: resource + indent, chat+feedback, icon, text string
     $r->print('<table cellspacing="3" cellpadding="0" bgcolor="#FFFFFF">' ."\n");      $r->print('<table cellspacing="0" cellpadding="3" border="0" bgcolor="#FFFFFF">' ."\n");
   
     my $mapIterator = $navmap->getIterator(undef, undef, \%filterHash);      # This needs to be updated to use symbs from the remote, 
       # instead of uris. The changes to this and the main rendering
       # loop should be obvious.
       # Here's a simple example of the iterator.
       # Preprocess the map: Look for current URL, force inlined maps to display
   
       # This currently does very little...
       #my $mapEventualIterator = Apache::lonnavmaps::iterator->new($navmap, undef, undef, {},
       #undef, $condition);
   
       my $mapIterator = $navmap->getIterator(undef, undef, {}, 1);
       my $found = 0;
       my $depth = 1;
       my $currentUrlIndex = 0; # keeps track of when the current resource is found,
                                # so we can back up a few and put the anchor above the
                                # current resource
       $mapIterator->next(); # discard the first BEGIN_MAP
     my $curRes = $mapIterator->next();      my $curRes = $mapIterator->next();
       my $counter = 0;
       
       while ($depth > 0) {
           if ($curRes == $mapIterator->BEGIN_MAP()) { $depth++; }
           if ($curRes == $mapIterator->END_MAP()) { $depth--; }
   
           if (ref($curRes)) { $counter++; }
   
           my $mapStack = $mapIterator->getStack();
           if ($currenturl && !$ENV{'form.alreadyHere'} && ref($curRes) && 
               $curRes->src() eq $currenturl) {
               # If this is the correct resource, be sure to 
               # show it by making sure the containing maps
               # are open.
   
               $currentUrlIndex = $counter;
               
               for my $map (@{$mapStack}) {
                   if ($condition) {
                       undef $filterHash{$map->map_pc()};
                   } else {
                       $filterHash{$map->map_pc()} = 1;
                   }
               }
               $ENV{'form.alreadyHere'} = 1;
           }
               
           # Preprocessing: If we're inlining nav maps into the top-level display,
           # make sure we show this map!
           if ($inlineTopLevelMaps && ref($curRes) && $curRes->is_map && 
               scalar(@{$mapStack}) == 1) {
               if ($condition) {
                   undef $filterHash{$curRes->map_pc()};
               } else {
                   $filterHash{$curRes->map_pc()} = 1;
               }
           }
   
           $curRes = $mapIterator->next();
       }
       
     undef $res; # so we don't accidentally use it later      undef $res; # so we don't accidentally use it later
     my $indentLevel = -1;      my $indentLevel = 0;
     my $indentString = "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";      my $indentString = "<img src=\"/adm/lonIcons/whitespace1.gif\" width=\"25\" height=\"1\" alt=\"\" border=\"0\" />";
   
     my $isNewBranch = 0;      my $isNewBranch = 0;
       my $now = time();
       my $in24Hours = $now + 24 * 60 * 60;
       my $displayedHereMarker = 0;
       
       # We know the first thing is a BEGIN_MAP (see "$self->{STARTED}"
       # code in iterator->next), so ignore the first one
       $mapIterator = $navmap->getIterator(undef, undef, \%filterHash,
                                              $condition);
       $mapIterator->next();
       $curRes = $mapIterator->next();
       my $deltadepth = 0;
       $depth = 1;
   
       my @backgroundColors = ("#FFFFFF", "#F6F6F6");
       my $rowNum = 0;
   
       $counter = 0;
   
       while ($depth > 0) {
           # If we're in a new style course, and this is a BEGIN_MAP, END_MAP, or
           # map resource and the stack depth is only one, just plain ignore this resource
           # entirely. (This has the effect of inlining the resources in that map
           # in the nav map.)
           if ($inlineTopLevelMaps && scalar(@{$mapIterator->getStack()}) == 1 &&
               ref($curRes) && $curRes->is_map()) {
               # We let the normal depth stuff occur, but we need to shift everything
               # over by one to the left to make it look right.
               $deltadepth = -1;
               $curRes = $mapIterator->next();
               next;
           }
   
     while ($curRes != $mapIterator->END_NAV_MAP) {  
         if ($curRes == $mapIterator->BEGIN_MAP() ||          if ($curRes == $mapIterator->BEGIN_MAP() ||
             $curRes == $mapIterator->BEGIN_BRANCH()) {              $curRes == $mapIterator->BEGIN_BRANCH()) {
             $indentLevel++;              $indentLevel++;
Line 882  sub new_handle { Line 1058  sub new_handle {
         if ($curRes == $mapIterator->BEGIN_BRANCH()) {          if ($curRes == $mapIterator->BEGIN_BRANCH()) {
             $isNewBranch = 1;              $isNewBranch = 1;
         }          }
           if ($curRes == $mapIterator->BEGIN_MAP()) { $depth++; }
           if ($curRes == $mapIterator->END_MAP()) { $depth--; }
   
           if (ref($curRes)) { $counter++; }
   
           if ($depth == 1) { $deltadepth = 0; } # we're done shifting, because we're
                                                 # out of the inlined map
   
           # Is this resource being blotted out?
           if (ref($curRes) && !advancedUser() && $curRes->randomout()) {
               $curRes = $mapIterator->next();
               next; # and totally ignore this resource
           }
   
         if (ref($curRes) && $curRes->src()) {          if (ref($curRes) && $curRes->src()) {
   
             my @parts;              # Step one: Decide which parts to show
               my @parts = @{$curRes->parts()};
               my $multipart = scalar(@parts) > 1;
               my $condensed = 0;
                   
             if ($curRes->is_problem()) {              if ($curRes->is_problem()) {
                 @parts = @{$curRes->parts()};                  # Is it multipart?
                 if (scalar(@parts) > 1) { shift(@parts); }  
                   if ($multipart) {
                       # If it's multipart, see if part 0 is "open"
                       # if it is, display all parts, if it isn't,
                       # just display first
                       if (!$curRes->opendate("0")) {
                           @parts = ("0"); # just display the zero-th part
                           $condensed = 1;
                       } else {
                           # Otherwise, only display part 0 if we want to 
                           # attach feedback or email information to it
                           if ($curRes->hasDiscussion() || $curRes->getFeedback()) {
                               shift @parts;
                           } else {
                               # If there's discussion or feedback, that counts
                               # as a difference, so display the parts.
                               
                               # Now, we decide whether to condense the
                               # parts due to similarity
                               my $status = $curRes->status($parts[1]);
                               my $due = $curRes->duedate($parts[1]);
                               my $open = $curRes->opendate($parts[1]);
                               my $statusAllSame = 1;
                               my $dueAllSame = 1;
                               my $openAllSame = 1;
                               for (my $i = 2; $i < scalar(@parts); $i++) {
                                   if ($curRes->status($parts[$i]) != $status){
                                       $statusAllSame = 0;
                                   }
                                   if ($curRes->duedate($parts[$i]) != $due ) {
                                       $dueAllSame = 0;
                                   }
                                   if ($curRes->opendate($parts[$i]) != $open) {
                                       $openAllSame = 0;
                                   }
                               }
                               
                               # $allSame is true if all the statuses were
                               # the same. Now, if they are all the same and
                               # match one of the statuses to condense, or they
                               # are all open with the same due date, or they are
                               # all OPEN_LATER with the same open date, display the
                               # status of the first non-zero part (to get the 'correct'
                               # status right, since 0 is never 'correct' or 'open').
                               if (($statusAllSame && defined($condenseStatuses{$status})) ||
                                   ($dueAllSame && $status == $curRes->OPEN && $statusAllSame)||
                                   ($openAllSame && $status == $curRes->OPEN_LATER && $statusAllSame) ){
                                   @parts = ($parts[1]);
                                   $condensed = 1;
                               }
                           }
                       }
                   }
   
             } else {              } else {
                 @parts[0] = "0"; # this is to get past foreach loop below                  $parts[0] = "0"; # this is to get past foreach loop below
                  # you can consider a non-problem resource as a resource                   # you can consider a non-problem resource as a resource
                  # with only one part without loss                    # with only one part without loss
               }
   
               # Is it a multipart problem with a single part, now in 
               # @parts with "0" filtered out? If so, forget it's a multi-part
               # problem and treat it like a single-part problem.
               if ( scalar(@parts) == 1 ) {
                   $multipart = 0;
               }
   
               # Display one part, in event of network error.
               # If this is a single part, we can at least show the correct
               # status, but if it's multipart, we're lost.
               if ($curRes->{RESOURCE_ERROR}) {
                   @parts = ("0");
             }              }
   
               # Step two: Show the parts
             foreach my $part (@parts) {              foreach my $part (@parts) {
   
                   my $deltalevel = 0; # for inserting the branch icon
                   my $nonLinkedText = ""; # unlinked stuff after title
                                   
                 # For each thing we're displaying...                  # For each thing we're displaying...
   
Line 908  sub new_handle { Line 1172  sub new_handle {
                     'symb='.&Apache::lonnet::escape($curRes->symb()).                      'symb='.&Apache::lonnet::escape($curRes->symb()).
                     '"';                      '"';
                 my $title = $curRes->title();                  my $title = $curRes->title();
                   if (!$title) {
                       $title = $curRes->src();
                       $title = substr ($title, rindex($title, "/") + 1);
                   }
                 my $partLabel = "";                  my $partLabel = "";
                 my $newBranchText = "";                  my $newBranchText = "";
   
                 # If this is a new branch, label it so                  # If this is a new branch, label it so
                 # (temporary, this should be an icon w/ alt text)                  # (temporary, this should be an icon w/ alt text)
                 if ($isNewBranch) {                  if ($isNewBranch) {
                     $newBranchText = "NB -> ";                      $newBranchText = "<img src=\"/adm/lonIcons/branch.gif\" border=\"0\">";
                     $isNewBranch = 0;                      $isNewBranch = 0;
                       $deltalevel = 1;
                 }                  }
   
                 # links to open and close the folders                  # links to open and close the folders
                 my $linkopen = "<a href=\"$link\">";                  my $linkopen = "<a href=\"$link\">";
                 my $linkclose = "</a>";                  my $linkclose = "</a>";
   
                 my $icon = "html.gif";                  my $icon = "<img src=\"/adm/lonIcons/html.gif\" alt=\"\" border=\"0\" />";
                 if ($curRes->is_problem()) {                   if ($curRes->is_problem()) { 
                     $icon = "problem.gif";                       if ($part eq "0" || $condensed) {
                           $icon = '<img src="/adm/lonIcons/problem.gif" alt="" border=\"0\" />'; 
                       } else {
                           $icon = $indentString;
                       }
                 }                  }
   
                 # Display the correct icon, link to open or shut map                  # Display the correct icon, link to open or shut map
                 if ($curRes->is_map()) {                   if ($curRes->is_map()) { 
                     my $mapId = $curRes->map_pc();                      my $mapId = $curRes->map_pc();
                     my $nowOpen = !defined($filterHash{$mapId});                      my $nowOpen = (!defined($filterHash{$mapId}));
                       if ($condition) {$nowOpen = !$nowOpen;}
                     $icon = $nowOpen ?                      $icon = $nowOpen ?
                         "folder_opened.gif" : "folder_closed.gif";                          "navmap.folder.closed.gif" : "navmap.folder.open.gif";
                       $icon = "<img src=\"/adm/lonIcons/$icon\" alt=\"\" border=\"0\" />";
                     $linkopen = "<a href=\"/adm/navmaps?filter=";                      $linkopen = "<a href=\"/adm/navmaps?filter=";
                     $linkopen .= $nowOpen ?                       $linkopen .= ($nowOpen xor $condition) ? 
                         addToFilter(\%filterHash, $mapId) :                          addToFilter(\%filterHash, $mapId) :
                         removeFromFilter(\%filterHash, $mapId);                          removeFromFilter(\%filterHash, $mapId);
                     $linkopen .= "\">";                      $linkopen .= "&condition=$condition&$queryAdd\">";
                     $linkclose = "</a>";                      $linkclose = "</a>";
                       
                 }                  }
                                   
                 my $colorizer = "";                  my $colorizer = "";
                   my $color;
                 if ($curRes->is_problem()) {                  if ($curRes->is_problem()) {
                     my $status = $curRes->status($part);                      my $status = $curRes->status($part);
                     my $color = $colormap{$status};                      $color = $colormap{$status};
   
                       # Special case in the navmaps: If in less then
                       # 24 hours, give it a bit of urgency
                       if (($status == $curRes->OPEN() || $status == $curRes->ATTEMPTED() ||
                            $status == $curRes->TRIES_LEFT())
                           && $curRes->duedate() &&
                           $curRes->duedate() < time()+(24*60*60) && 
                           $curRes->duedate() > time()) {
                           $color = $hurryUpColor;
                       }
                       # Special case: If this is the last try, and there is
                       # more then one available, and it's not due yet, give a bit of urgency
                       my $tries = $curRes->tries($part);
                       my $maxtries = $curRes->maxtries($part);
                       if ($tries && $maxtries && $maxtries > 1 &&
                           $maxtries - $tries == 1 && $curRes->duedate() &&
                           $curRes->duedate() > time()) {
                           $color = $hurryUpColor;
                       }
                     if ($color ne "") {                      if ($color ne "") {
                         $colorizer = "bgcolor=\"$color\"";                          $colorizer = "bgcolor=\"$color\"";
                     }                      }
                 }                  }
   
                 $r->print("  <tr><td align=\"left\" valign=\"top\">\n");                  if ($curRes->randomout()) {
                       $nonLinkedText .= ' <i>(hidden)</i> ';
                   }
   
                   $rowNum++;
                   my $backgroundColor = $backgroundColors[$rowNum % scalar(@backgroundColors)];
   
                   # FIRST COL: The resource indentation, branch icon, name, and anchor
                   $r->print("  <tr bgcolor=\"$backgroundColor\"><td align=\"left\" valign=\"center\" width=\"60%\">\n");
   
                   # anchor for current resource... - 5 is deliberate: If it's that
                   # high on the screen, don't bother focusing on it. Also this will
                   # print multiple anchors if this is an expanded multi-part problem...
                   # who cares?
                   if ($counter == $currentUrlIndex - 5) {
                       $r->print('<a name="current" />');
                   }
   
                 # print indentation                  # print indentation
                 for (my $i = 0; $i < $indentLevel; $i++) {                  for (my $i = 0; $i < $indentLevel - $deltalevel + $deltadepth; $i++) {
                     $r->print($indentString);                      $r->print($indentString);
                 }                  }
   
                 $r->print("  ${newBranchText}${linkopen}<img border=\"0\" src=\"" .                  $r->print("  ${newBranchText}${linkopen}$icon${linkclose}\n");
                           "/adm/lonIcons/$icon\" alt=\"\">${linkclose}\n");  
                   my $curMarkerBegin = "";
                   my $curMarkerEnd = "";
   
                   # Is this the current resource?
                   if ($curRes->src() eq $currenturl && !$displayedHereMarker) {
                       $curMarkerBegin = '<a name="curloc" /><font color="red" size="+2">&gt; </font>';
                       $curMarkerEnd = '<font color="red" size="+2"> &lt;</font>';
                       $displayedHereMarker = 1;
                   }
   
                   if ($curRes->is_problem() && $part ne "0" && !$condensed) { 
                       $partLabel = " (Part $part)"; 
                       $title = "";
                   }
                   if ($multipart && $condensed) {
                       $nonLinkedText .= ' (' . $curRes->countParts() . ' parts)';
                   }
   
                   $r->print("  $curMarkerBegin<a href=\"$link\">$title$partLabel</a> $curMarkerEnd $nonLinkedText");
                   #$r->print(" TDV:" . $curRes->{DATA}->{TOP_DOWN_VAL}); # temp
                   #$r->print(" BUV:" . $curRes->{DATA}->{BOT_UP_VAL}); # temp
                   #$r->print(" DD:" . $curRes->{DATA}->{DISPLAY_DEPTH}); # temp
   
                   if ($curRes->{RESOURCE_ERROR}) {
                       $r->print(&Apache::loncommon::help_open_topic ("Navmap_Host_Down",
                                                 '<font size="-1">Host down</font>'));
                       }
   
                   my $discussionHTML = ""; my $feedbackHTML = "";
   
                   # SECOND COL: Is there text, feedback, errors??
                   if ($curRes->hasDiscussion()) {
                       $discussionHTML = $linkopen .
                           '<img border="0" src="/adm/lonMisc/chat.gif" />' .
                           $linkclose;
                   }
   
                   if ($curRes->getFeedback()) {
                       my $feedback = $curRes->getFeedback();
                       foreach (split(/\,/, $feedback)) {
                           if ($_) {
                               $feedbackHTML .= '&nbsp;<a href="/adm/email?display='
                                   . &Apache::lonnet::escape($_) . '">'
                                   . '<img src="/adm/lonMisc/feedback.gif" '
                                   . 'border="0" /></a>';
                           }
                       }
                   }
   
                   $r->print("<td width=\"75\" align=\"left\" valign=\"center\">$discussionHTML$feedbackHTML&nbsp;</td>");
   
                 if ($curRes->is_problem() && $part != "0") { $partLabel = " (Part $part)"; }                  # Is this the first displayed part of a multi-part problem
                   # that has not been condensed, so we should suppress these two
                   # columns?
                   my $firstDisplayed = !$condensed && $multipart && $part eq "0";
   
                   # THIRD COL: Problem status icon
                   if ($curRes->is_problem() &&
                       !$firstDisplayed) {
                       my $icon = $statusIconMap{$curRes->status($part)};
                       my $alt = $iconAltTags{$icon};
                       if ($icon) {
                           $r->print("<td width=\"30\" valign=\"center\" width=\"50\" align=\"right\">$linkopen<img width=\"25\" height=\"25\" src=\"/adm/lonIcons/$icon\" border=\"0\" alt=\"$alt\" />$linkclose</td>\n");
                       } else {
                           $r->print("<td width=\"30\">&nbsp;</td>\n");
                       }
                   } else { # not problem, no icon
                       $r->print("<td width=\"30\">&nbsp;</td>\n");
                   }
   
                 $r->print("  <a href=\"$link\">$title$partLabel</a></td>".                  # FOURTH COL: Text description
                           "<td $colorizer align=\"right\">\n");                  #$r->print("<td $colorizer align=\"right\" valign=\"center\">\n");
                   $r->print("<td align=\"right\" valign=\"center\">\n");
                                   
                 if ($curRes->kind() eq "res" and                   if ($curRes->kind() eq "res" &&
                     $curRes->is_problem() ) {                      $curRes->is_problem() &&
                       !$firstDisplayed) {
                       $r->print ("<font color=\"$color\"><b>") if ($color);
                     $r->print (getDescription($curRes, $part));                      $r->print (getDescription($curRes, $part));
                       $r->print ("</b></font>") if ($color);
                 }                  }
                   if ($curRes->is_map() && advancedUser() && $curRes->randompick()) {
                       $r->print('(randomly select ' . $curRes->randompick() .')');
                   }
   
                   $r->print("&nbsp;</td></tr>\n");
             }              }
         }          }
         $curRes = $mapIterator->next();          $curRes = $mapIterator->next();
Line 977  sub new_handle { Line 1364  sub new_handle {
   
     $r->print("</table></body></html>");      $r->print("</table></body></html>");
   
       $navmap->untieHashes();
   
     return OK;      return OK;
 }  }
   
Line 1035  sub getLinkForResource { Line 1424  sub getLinkForResource {
 sub getDescription {  sub getDescription {
     my $res = shift;      my $res = shift;
     my $part = shift;      my $part = shift;
     my $status = $res->getDateStatus();      my $status = $res->status($part);
   
     if ($status == $res->NETWORK_FAILURE) { return ""; }      if ($status == $res->NETWORK_FAILURE) { return ""; }
     if ($status == $res->NOTHING_SET) {      if ($status == $res->NOTHING_SET) {
         return "Not currently assigned.";          return "Not currently assigned.";
     }      }
     if ($status == $res->OPEN_LATER) {      if ($status == $res->OPEN_LATER) {
         return "Opens: " . timeToHumanString($res->opendate($part));          return "Open " . timeToHumanString($res->opendate($part));
     }      }
     if ($status == $res->OPEN) {      if ($status == $res->OPEN) {
         return "Due: " . timeToHumanString($res->duedate($part));          if ($res->duedate($part)) {
               return "Due " . timeToHumanString($res->duedate($part));
           } else {
               return "Open, no due date";
           }
       }
       if ($status == $res->PAST_DUE_ANSWER_LATER) {
           return "Answer open " . timeToHumanString($res->answerdate($part));
     }      }
     if ($status == $res->PAST_DUE) {      if ($status == $res->PAST_DUE_NO_ANSWER) {
         return "Answer: " . timeToHumanString($res->duedate($part));          return "Was due " . timeToHumanString($res->duedate($part));
     }      }
     if ($status == $res->ANSWER_OPEN) {      if ($status == $res->ANSWER_OPEN) {
         return "Answer available";          return "Answer available";
     }      }
       if ($status == $res->EXCUSED) {
           return "Excused by instructor";
       }
       if ($status == $res->ATTEMPTED) {
           return "Not yet graded.";
       }
       if ($status == $res->TRIES_LEFT) {
           my $tries = $res->tries($part);
           my $maxtries = $res->maxtries($part);
           my $triesString = "";
           if ($tries && $maxtries) {
               $triesString = "<font size=\"-1\"><i>($tries of $maxtries tries used)</i></font>";
               if ($maxtries > 1 && $maxtries - $tries == 1) {
                   $triesString = "<b>$triesString</b>";
               }
           }
           if ($res->duedate()) {
               return "Due " . timeToHumanString($res->duedate($part)) .
                   " $triesString";
           } else {
               return "No due date $triesString";
           }
       }
   }
   
   sub advancedUser {
       return $ENV{'user.adv'};
 }  }
   
 # I want to change this into something more human-friendly. For  
 # now, this is a simple call to localtime. The final function  # timeToHumanString takes a time number and converts it to a
 # probably belongs in loncommon.  # human-readable representation, meant to be used in the following
   # manner:
   # print "Due $timestring"
   # print "Open $timestring"
   # print "Answer available $timestring"
   # Very, very, very, VERY English-only... goodness help a localizer on
   # this func...
 sub timeToHumanString {  sub timeToHumanString {
     return localtime(shift);      my ($time) = @_;
       # zero, '0' and blank are bad times
       if (!$time) {
           return 'never';
       }
   
       my $now = time();
   
       my @time = localtime($time);
       my @now = localtime($now);
   
       # Positive = future
       my $delta = $time - $now;
   
       my $minute = 60;
       my $hour = 60 * $minute;
       my $day = 24 * $hour;
       my $week = 7 * $day;
       my $inPast = 0;
   
       # Logic in comments:
       # Is it now? (extremely unlikely)
       if ( $delta == 0 ) {
           return "this instant";
       }
   
       if ($delta < 0) {
           $inPast = 1;
           $delta = -$delta;
       }
   
       # Is it in the future?
       if ( $delta > 0 ) {
           # Is it less then a minute away?
           my $tense = $inPast ? " ago" : "";
           my $prefix = $inPast ? "" : "in ";
           if ( $delta < $minute ) {
               if ($delta == 1) { return "${prefix}1 second$tense"; }
               return "$prefix$delta seconds$tense";
           }
   
           # Is it less then an hour away?
           if ( $delta < $hour ) {
               # If so, use minutes
               my $minutes = floor($delta / 60);
               if ($minutes == 1) { return "${prefix}1 minute$tense"; }
               return "$prefix$minutes minutes$tense";
           }
           
           # Is it less then 24 hours away? If so,
           # display hours + minutes
           if ( $delta < $hour * 24) {
               my $hours = floor($delta / $hour);
               my $minutes = floor(($delta % $hour) / $minute);
               my $hourString = "$hours hours";
               my $minuteString = ", $minutes minutes";
               if ($hours == 1) {
                   $hourString = "1 hour";
               }
               if ($minutes == 1) {
                   $minuteString = ", 1 minute";
               }
               if ($minutes == 0) {
                   $minuteString = "";
               }
               return "$prefix$hourString$minuteString$tense";
           }
   
           # Less then 5 days away, display day of the week and
           # HH:MM
           if ( $delta < $day * 5 ) {
               my $timeStr = strftime("%A, %b %e at %I:%M %P", localtime($time));
               $timeStr =~ s/12:00 am/midnight/;
               $timeStr =~ s/12:00 pm/noon/;
               return ($inPast ? "last " : "next ") .
                   $timeStr;
           }
           
           # Is it this year?
           if ( $time[5] == $now[5]) {
               # Return on Month Day, HH:MM meridian
               my $timeStr = strftime("on %A, %b %e at %I:%M %P", localtime($time));
               $timeStr =~ s/12:00 am/midnight/;
               $timeStr =~ s/12:00 pm/noon/;
               return $timeStr;
           }
   
           # Not this year, so show the year
           my $timeStr = strftime("on %A, %b %e %G at %I:%M %P", localtime($time));
           $timeStr =~ s/12:00 am/midnight/;
           $timeStr =~ s/12:00 pm/noon/;
           return $timeStr;
       }
 }  }
   
 1;  1;
   
 package Apache::lonnavmaps::navmap;  package Apache::lonnavmaps::navmap;
   
 # LEFT:  
 # * Actual handler code (multi-part)  
 # * Branches (aieee!) (and conditionals)  
   
 =pod  =pod
   
 lonnavmaps provides functions and objects for dealing with the compiled course hashes generated when a user enters the course, and also provides the Apache handler for the "Navigation Map" button.  lonnavmaps provides functions and objects for dealing with the compiled course hashes generated when a user enters the course, and also provides the Apache handler for the "Navigation Map" button.
Line 1087  You must obtain resource objects through Line 1603  You must obtain resource objects through
   
 =over 4  =over 4
   
 =item * B<new>(filename, parmHashFile, genCourseAndUserOptions): Binds a new navmap object to the compiled course representation and parmHashFile. genCourseAndUserOptions is a flag saying whether the course options and user options hash should be generated. This is for when you are using the parameters of the resources that require them; see documentation in resource object documentation. Returns the navmap object if this is successful, or B<undef> if not. You must check for undef; errors will occur when you try to use the other methods otherwise.  =item * B<new>(navHashFile, parmHashFile, genCourseAndUserOptions, genMailDiscussStatus): Binds a new navmap object to the compiled nav map hash and parm hash given as filenames. genCourseAndUserOptions is a flag saying whether the course options and user options hash should be generated. This is for when you are using the parameters of the resources that require them; see documentation in resource object documentation. genMailDiscussStatus causes the nav map to retreive information about the email and discussion status of resources. Returns the navmap object if this is successful, or B<undef> if not. You must check for undef; errors will occur when you try to use the other methods otherwise.
   
 =item * B<getIterator>(first, finish, filter, condition): See iterator documentation below.  =item * B<getIterator>(first, finish, filter, condition): See iterator documentation below.
   
Line 1105  sub new { Line 1621  sub new {
     $self->{NAV_HASH_FILE} = shift;      $self->{NAV_HASH_FILE} = shift;
     $self->{PARM_HASH_FILE} = shift;      $self->{PARM_HASH_FILE} = shift;
     $self->{GENERATE_COURSE_USER_OPT} = shift;      $self->{GENERATE_COURSE_USER_OPT} = shift;
       $self->{GENERATE_EMAIL_DISCUSS_STATUS} = shift;
   
     # Resource cache stores navmapresource's as we reference them. We generate      # Resource cache stores navmapresource's as we reference them. We generate
     # them on-demand so we don't pay for creating resources unless we use them.      # them on-demand so we don't pay for creating resources unless we use them.
Line 1126  sub new { Line 1643  sub new {
     if (!(tie(%parmhash, 'GDBM_File', $self->{PARM_HASH_FILE},      if (!(tie(%parmhash, 'GDBM_File', $self->{PARM_HASH_FILE},
               &GDBM_READER(), 0640)))                &GDBM_READER(), 0640)))
     {      {
           untie $self->{PARM_HASH};
         return undef;          return undef;
     }      }
     $self->{PARM_HASH} = \%parmhash;      $self->{PARM_HASH} = \%parmhash;
     $self->{HASH_TIED} = 1;      $self->{HASH_TIED} = 1;
   
       bless($self);
           
       return $self;
   }
   
   sub init {
       my $self = shift;
   
     # If the course opt hash and the user opt hash should be generated,      # If the course opt hash and the user opt hash should be generated,
     # generate them      # generate them
     if ($self->{GENERATE_COURSE_USER_OPT}) {      if ($self->{GENERATE_COURSE_USER_OPT}) {
Line 1182  sub new { Line 1708  sub new {
                 $useropt{$userprefix.&Apache::lonnet::unescape($name)}=                  $useropt{$userprefix.&Apache::lonnet::unescape($name)}=
                     &Apache::lonnet::unescape($value);                      &Apache::lonnet::unescape($value);
             }              }
         $self->{COURSE_OPT} = \%courseopt;              $self->{COURSE_OPT} = \%courseopt;
         $self->{USER_OPT} = \%useropt;              $self->{USER_OPT} = \%useropt;
         }          }
     }         }   
   
     bless($self);      if ($self->{GENERATE_EMAIL_DISCUSS_STATUS}) {
           my $cid=$ENV{'request.course.id'};
           my ($cdom,$cnum)=split(/\_/,$cid);
           
           my %emailstatus = &Apache::lonnet::dump('email_status');
           my $logoutTime = $emailstatus{'logout'};
           my $courseLeaveTime = $emailstatus{'logout_'.$ENV{'request.course.id'}};
           $self->{LAST_CHECK} = ($courseLeaveTime > $logoutTime ?
                                  $courseLeaveTime : $logoutTime);
           my %discussiontime = &Apache::lonnet::dump('discussiontimes', 
                                                      $cdom, $cnum);
           my %feedback=();
           my %error=();
           my $keys = &Apache::lonnet::reply('keys:'.
                                             $ENV{'user.domain'}.':'.
                                             $ENV{'user.name'}.':nohist_email',
                                             $ENV{'user.home'});
   
           foreach my $msgid (split(/\&/, $keys)) {
               $msgid=&Apache::lonnet::unescape($msgid);
               my $plain=&Apache::lonnet::unescape(&Apache::lonnet::unescape($msgid));
               if ($plain=~/(Error|Feedback) \[([^\]]+)\]/) {
                   my ($what,$url)=($1,$2);
                   my %status=
                       &Apache::lonnet::get('email_status',[$msgid]);
                   if ($status{$msgid}=~/^error\:/) { 
                       $status{$msgid}=''; 
                   }
                   
                   if (($status{$msgid} eq 'new') || 
                       (!$status{$msgid})) { 
                       if ($what eq 'Error') {
                           $error{$url}.=','.$msgid; 
                       } else {
                           $feedback{$url}.=','.$msgid;
                       }
                   }
               }
           }
           
           $self->{FEEDBACK} = \%feedback;
           $self->{ERROR_MSG} = \%error; # what is this? JB
           $self->{DISCUSSION_TIME} = \%discussiontime;
           $self->{EMAIL_STATUS} = \%emailstatus;
           
       }    
   
     return $self;      $self->{PARM_CACHE} = {};
   }
   
   # Checks to see if coursemap is defined, matching test in old lonnavmaps
   sub courseMapDefined {
       my $self = shift;
       my $uri = &Apache::lonnet::clutter($ENV{'request.course.uri'});
   
       my $firstres = $self->{NAV_HASH}->{"map_start_$uri"};
       my $lastres = $self->{NAV_HASH}->{"map_finish_$uri"};
       return $firstres && $lastres;
 }  }
   
 sub getIterator {  sub getIterator {
     my $self = shift;      my $self = shift;
     my $iterator = Apache::lonnavmaps::iterator->new($self, shift, shift,      my $iterator = Apache::lonnavmaps::iterator->new($self, shift, shift,
                                                      shift, shift);                                                       shift, undef, shift, 
                                                        $ENV{'form.direction'});
     return $iterator;      return $iterator;
 }  }
   
 # unties the hash when done  # unties the hash when done
 sub untieHashes {  sub untieHashes {
     my $self = shift;      my $self = shift;
     untie $self->{NAV_HASH} if ($self->{HASH_TIED});      untie %{$self->{NAV_HASH}} if ($self->{HASH_TIED});
     untie $self->{PARM_HASH} if ($self->{HASH_TIED});      untie %{$self->{PARM_HASH}} if ($self->{HASH_TIED});
     $self->{HASH_TIED} = 0;      $self->{HASH_TIED} = 0;
 }  }
   
Line 1213  sub DESTROY { Line 1795  sub DESTROY {
     $self->untieHashes();      $self->untieHashes();
 }  }
   
   # Private function: Does the given resource (as a symb string) have
   # current discussion? Returns 0 if chat/mail data not extracted.
   sub hasDiscussion {
       my $self = shift;
       my $symb = shift;
       if (!defined($self->{DISCUSSION_TIME})) { return 0; }
   
       return $self->{DISCUSSION_TIME}->{$symb} >
              $self->{LAST_CHECK};
   }
   
   # Private function: Does the given resource (as a symb string) have
   # current feedback? Returns the string in the feedback hash, which
   # will be false if it does not exist.
   sub getFeedback { 
       my $self = shift;
       my $symb = shift;
   
       if (!defined($self->{FEEDBACK})) { return ""; }
       
       return $self->{FEEDBACK}->{$symb};
   }
   
 =pod  =pod
   
 =item * B<getById>(id): Based on the ID of the resource (1.1, 3.2, etc.), get a resource object for that resource. This method, or other methods that use it (as in the resource object) is the only proper way to obtain a resource object.  =item * B<getById>(id): Based on the ID of the resource (1.1, 3.2, etc.), get a resource object for that resource. This method, or other methods that use it (as in the resource object) is the only proper way to obtain a resource object.
Line 1274  sub finishResource { Line 1879  sub finishResource {
 sub parmval {  sub parmval {
     my $self = shift;      my $self = shift;
     my ($what,$symb)=@_;      my ($what,$symb)=@_;
       my $hashkey = $what."|||".$symb;
   
       if (defined($self->{PARM_CACHE}->{$hashkey})) {
           return $self->{PARM_CACHE}->{$hashkey};
       }
   
       my $result = $self->parmval_real($what, $symb);
       $self->{PARM_CACHE}->{$hashkey} = $result;
       return $result;
   }
   
   sub parmval_real {
       my $self = shift;
       my ($what,$symb) = @_;
   
     my $cid=$ENV{'request.course.id'};      my $cid=$ENV{'request.course.id'};
     my $csec=$ENV{'request.course.sec'};      my $csec=$ENV{'request.course.sec'};
     my $uname=$ENV{'user.name'};      my $uname=$ENV{'user.name'};
Line 1307  sub parmval { Line 1927  sub parmval {
   
 # ---------------------------------------------------------- first, check user  # ---------------------------------------------------------- first, check user
     if ($uname and defined($useropt)) {      if ($uname and defined($useropt)) {
         if ($$useropt{$courselevelr}) { return $$useropt{$courselevelr}; }          if (defined($$useropt{$courselevelr})) { return $$useropt{$courselevelr}; }
         if ($$useropt{$courselevelm}) { return $$useropt{$courselevelm}; }          if (defined($$useropt{$courselevelm})) { return $$useropt{$courselevelm}; }
         if ($$useropt{$courselevel}) { return $$useropt{$courselevel}; }          if (defined($$useropt{$courselevel})) { return $$useropt{$courselevel}; }
     }      }
   
 # ------------------------------------------------------- second, check course  # ------------------------------------------------------- second, check course
     if ($csec and defined($courseopt)) {      if ($csec and defined($courseopt)) {
         if ($$courseopt{$seclevelr}) { return $$courseopt{$seclevelr}; }          if (defined($$courseopt{$seclevelr})) { return $$courseopt{$seclevelr}; }
         if ($$courseopt{$seclevelm}) { return $$courseopt{$seclevelm}; }          if (defined($$courseopt{$seclevelm})) { return $$courseopt{$seclevelm}; }
         if ($$courseopt{$seclevel}) { return $$courseopt{$seclevel}; }          if (defined($$courseopt{$seclevel})) { return $$courseopt{$seclevel}; }
     }      }
   
     if (defined($courseopt)) {      if (defined($courseopt)) {
         if ($$courseopt{$courselevelr}) { return $$courseopt{$courselevelr}; }          if (defined($$courseopt{$courselevelr})) { return $$courseopt{$courselevelr}; }
         if ($$courseopt{$courselevelm}) { return $$courseopt{$courselevelm}; }          if (defined($$courseopt{$courselevelm})) { return $$courseopt{$courselevelm}; }
         if ($$courseopt{$courselevel}) { return $$courseopt{$courselevel}; }          if (defined($$courseopt{$courselevel})) { return $$courseopt{$courselevel}; }
     }      }
   
 # ----------------------------------------------------- third, check map parms  # ----------------------------------------------------- third, check map parms
   
     my $thisparm=$$parmhash{$symbparm};      my $thisparm=$$parmhash{$symbparm};
     if ($thisparm) { return $thisparm; }      if (defined($thisparm)) { return $thisparm; }
   
 # ----------------------------------------------------- fourth , check default  # ----------------------------------------------------- fourth , check default
   
     my $default=&Apache::lonnet::metadata($fn,$rwhat.'.default');      my $default=&Apache::lonnet::metadata($fn,$rwhat.'.default');
     if ($default) { return $default}      if (defined($default)) { return $default}
   
 # --------------------------------------------------- fifth , cascade up parts  # --------------------------------------------------- fifth , cascade up parts
   
Line 1343  sub parmval { Line 1963  sub parmval {
         my ($part,$id)=split(/\_/,$space);          my ($part,$id)=split(/\_/,$space);
         if ($id) {          if ($id) {
             my $partgeneral=$self->parmval($part.".$qualifier",$symb);              my $partgeneral=$self->parmval($part.".$qualifier",$symb);
             if ($partgeneral) { return $partgeneral; }              if (defined($partgeneral)) { return $partgeneral; }
         } else {          } else {
             my $resourcegeneral=$self->parmval("0.$qualifier",$symb);              my $resourcegeneral=$self->parmval("0.$qualifier",$symb);
             if ($resourcegeneral) { return $resourcegeneral; }              if (defined($resourcegeneral)) { return $resourcegeneral; }
         }          }
     }      }
     return '';      return '';
Line 1381  getIterator behaves as follows: Line 2001  getIterator behaves as follows:
   
 =over 4  =over 4
   
 =item B<getIterator>(nav_map, firstResource, finishResource, filterHash): All parameters are optional. firstResource is a resource reference corresponding to where the iterator should start. It defaults to navmap->firstResource() for the corresponding nav map. finishResource corresponds to where you want the iterator to end, defaulting to navmap->finishResource(). It is your responsibility to ensure that the iterator will actually get there. filterHash is a hash used as a set containing strings representing the resource IDs, defaulting to empty. Condition is a 1 or 0 that sets what to do with the filter hash: If a 1, then only resource that exist IN the filterHash will be recursed on. If it is a 0, only resources NOT in the filterHash will be recursed on. Defaults to 0.  =item B<getIterator>(firstResource, finishResource, filterHash, condition, direction): All parameters are optional. firstResource is a resource reference corresponding to where the iterator should start. It defaults to navmap->firstResource() for the corresponding nav map. finishResource corresponds to where you want the iterator to end, defaulting to navmap->finishResource(). filterHash is a hash used as a set containing strings representing the resource IDs, defaulting to empty. Condition is a 1 or 0 that sets what to do with the filter hash: If a 0, then only resource that exist IN the filterHash will be recursed on. If it is a 1, only resources NOT in the filterHash will be recursed on. Defaults to 0, which is to say, do not recurse unless explicitly asked to. Direction specifies which direction to recurse, either FORWARD or BACKWARD, with FORWARD being default.
   
 Thus, by default, all resources will be shown. Change the condition to a 1 without changing the hash, and only the top level of the map will be shown. Changing the condition to 1 and including some values in the hash will allow you to selectively examine parts of the navmap, while leaving it on 0 and adding things to the hash will allow you to selectively ignore parts of the nav map. See the handler code for examples.  Thus, by default, all resources will be shown. Change the condition to a 1 without changing the hash, and only the top level of the map will be shown. Changing the condition to 1 and including some values in the hash will allow you to selectively examine parts of the navmap, while leaving it on 0 and adding things to the hash will allow you to selectively ignore parts of the nav map. See the handler code for examples: By default, the condition is 0 and all folders are closed unless explicitly opened. Clicking "Show All Resources" will use a condition of 1 and an empty filterHash, resulting in all resources being shown.
   
 The iterator will return either a reference to a resource object, or a token representing something in the map, such as the beginning of a new branch. The possible tokens are:  The iterator will return either a reference to a resource object, or a token representing something in the map, such as the beginning of a new branch. The possible tokens are:
   
 =over 4  =over 4
   
 =item * some list of tokens here  =item * BEGIN_MAP: A new map is being recursed into. This is returned I<after> the map resource itself is returned.
   
   =item * END_MAP: The map is now done.
   
   =item * BEGIN_BRANCH: A branch is now starting. The next resource returned will be the first in that branch.
   
   =item * END_BRANCH: The branch is now done.
   
 =back  =back
   
 The tokens are retreivable via methods on the iterator object, i.e., $iterator->END_NAV_MAP. (Perl will automatically optimize these into constants.  The tokens are retreivable via methods on the iterator object, i.e., $iterator->END_MAP.
   
   =back
   
 =cut  =cut
   
 # Here are the tokens for the iterator:  # Here are the tokens for the iterator:
   
 sub END_NAV_MAP { return 0; }  # Represents end of entire nav map  
 sub BEGIN_MAP { return 1; }    # begining of a new map  sub BEGIN_MAP { return 1; }    # begining of a new map
 sub END_MAP { return 2; }      # end of the map  sub END_MAP { return 2; }      # end of the map
 sub BEGIN_BRANCH { return 3; } # beginning of a branch  sub BEGIN_BRANCH { return 3; } # beginning of a branch
 sub END_BRANCH { return 4; }   # end of a branch  sub END_BRANCH { return 4; }   # end of a branch
   sub FORWARD { return 1; }      # go forward
   sub BACKWARD { return 2; }
   
   sub min {
       (my $a, my $b) = @_;
       if ($a < $b) { return $a; } else { return $b; }
   }
   
   sub new {
       # magic invocation to create a class instance
       my $proto = shift;
       my $class = ref($proto) || $proto;
       my $self = {};
   
       $self->{NAV_MAP} = shift;
       return undef unless ($self->{NAV_MAP});
   
       # Handle the parameters
       $self->{FIRST_RESOURCE} = shift || $self->{NAV_MAP}->firstResource();
       $self->{FINISH_RESOURCE} = shift || $self->{NAV_MAP}->finishResource();
   
       # If the given resources are just the ID of the resource, get the
       # objects
       if (!ref($self->{FIRST_RESOURCE})) { $self->{FIRST_RESOURCE} = 
                $self->{NAV_MAP}->getById($self->{FIRST_RESOURCE}); }
       if (!ref($self->{FINISH_RESOURCE})) { $self->{FINISH_RESOURCE} = 
                $self->{NAV_MAP}->getById($self->{FINISH_RESOURCE}); }
   
       $self->{FILTER} = shift;
   
       # A hash, used as a set, of resource already seen
       $self->{ALREADY_SEEN} = shift;
       if (!defined($self->{ALREADY_SEEN})) { $self->{ALREADY_SEEN} = {} };
       $self->{CONDITION} = shift;
   
       # Now, we need to pre-process the map, by walking forward and backward
       # over the parts of the map we're going to look at.
   
       # The processing steps are exactly the same, except for a few small 
       # changes, so I bundle those up in the following list of two elements:
       # (direction_to_iterate, VAL_name, next_resource_method_to_call,
       # first_resource).
       # This prevents writing nearly-identical code twice.
       my @iterations = ( [FORWARD(), 'TOP_DOWN_VAL', 'getNext', 
                           'FIRST_RESOURCE'],
                          [BACKWARD(), 'BOT_UP_VAL', 'getPrevious', 
                           'FINISH_RESOURCE'] );
   
       my $maxDepth = 0; # tracks max depth
   
       foreach my $pass (@iterations) {
           my $direction = $pass->[0];
           my $valName = $pass->[1];
           my $nextResourceMethod = $pass->[2];
           my $firstResourceName = $pass->[3];
   
           my $iterator = Apache::lonnavmaps::DFSiterator->new($self->{NAV_MAP}, 
                                                               $self->{FIRST_RESOURCE},
                                                               $self->{FINISH_RESOURCE},
                                                               {}, undef, 0, $direction);
       
           # prime the recursion
           $self->{$firstResourceName}->{DATA}->{$valName} = 0;
           my $depth = 0;
           $iterator->next();
           my $curRes = $iterator->next();
           while ($depth > -1) {
               if ($curRes == $iterator->BEGIN_MAP()) { $depth++; }
               if ($curRes == $iterator->END_MAP()) { $depth--; }
           
               if (ref($curRes)) {
                   my $resultingVal = $curRes->{DATA}->{$valName};
                   my $nextResources = $curRes->$nextResourceMethod();
                   my $resourceCount = scalar(@{$nextResources});
               
                   if ($resourceCount == 1) {
                       my $current = $nextResources->[0]->{DATA}->{$valName} || 999999999;
                       $nextResources->[0]->{DATA}->{$valName} = min($resultingVal, $current);
                   }
                   
                   if ($resourceCount > 1) {
                       foreach my $res (@{$nextResources}) {
                           my $current = $res->{DATA}->{$valName} || 999999999;
                           $res->{DATA}->{$valName} = min($current, $resultingVal + 1);
                       }
                   }
               }
               if (ref($curRes) && $curRes->is_map() && $direction == FORWARD()) {
                   my $firstResource = $curRes->map_start();
                   my $finishResource = $curRes->map_finish();
                   my $newIterator = Apache::lonnavmaps::iterator->new($self->{NAV_MAP},
                                                                       $firstResource,
                                                                       $finishResource,
                                                                       $self->{FILTER},
                                                                       $self->{ALREADY_SEEN},
                                                                       $self->{CONDITION});
               }
               
               # Assign the final val
               if (ref($curRes) && $direction == BACKWARD()) {
                   my $finalDepth = min($curRes->{DATA}->{TOP_DOWN_VAL},
                                        $curRes->{DATA}->{BOT_UP_VAL});
                   
                   $curRes->{DATA}->{DISPLAY_DEPTH} = $finalDepth;
                   if ($finalDepth > $maxDepth) {$maxDepth = $finalDepth;}
                   }
               $curRes = $iterator->next();
           }
       }
   
       # Set up some bookkeeping information.
       $self->{CURRENT_DEPTH} = 0;
       $self->{MAX_DEPTH} = $maxDepth;
       $self->{STACK} = [];
       $self->{RECURSIVE_ITERATOR_FLAG} = 0;
   
       for (my $i = 0; $i <= $self->{MAX_DEPTH}; $i++) {
           push @{$self->{STACK}}, [];
       }
   
       # Prime the recursion w/ the first resource
       push @{$self->{STACK}->[0]}, $self->{FIRST_RESOURCE};
       $self->{ALREADY_SEEN}->{$self->{FIRST_RESOURCE}->{ID}} = 1;
   
       bless ($self);
   
       return $self;
   }
   
   sub next {
       my $self = shift;
   
       if ($self->{RECURSIVE_ITERATOR_FLAG}) {
           # grab the next from the recursive iterator 
           my $next = $self->{RECURSIVE_ITERATOR}->next();
   
           # is it a begin or end map? If so, update the depth
           if ($next == BEGIN_MAP() ) { $self->{RECURSIVE_DEPTH}++; }
           if ($next == END_MAP() ) { $self->{RECURSIVE_DEPTH}--; }
   
           # Are we back at depth 0? If so, stop recursing
           if ($self->{RECURSIVE_DEPTH} == 0) {
               $self->{RECURSIVE_ITERATOR_FLAG} = 0;
           }
   
           return $next;
       }
   
       if (defined($self->{FORCE_NEXT})) {
           my $tmp = $self->{FORCE_NEXT};
           $self->{FORCE_NEXT} = undef;
           return $tmp;
       }
   
       # Have we not yet begun? If not, return BEGIN_MAP and
       # remember we've started.
       if ( !$self->{STARTED} ) { 
           $self->{STARTED} = 1;
           return $self->BEGIN_MAP();
       }
   
       # Here's the guts of the iterator.
       
       # Find the next resource, if any.
       my $found = 0;
       my $i = $self->{MAX_DEPTH};
       my $newDepth;
       my $here;
       while ( $i >= 0 && !$found ) {
           if ( scalar(@{$self->{STACK}->[$i]}) > 0 ) {
               $here = $self->{HERE} = shift @{$self->{STACK}->[$i]};
               $found = 1;
               $newDepth = $i;
           }
           $i--;
       }
   
       # If we still didn't find anything, we're done.
       if ( !$found ) {
           # We need to get back down to the correct branch depth
           if ( $self->{CURRENT_DEPTH} > 0 ) {
               $self->{CURRENT_DEPTH}--;
               return END_BRANCH();
           } else {
               return END_MAP();
           }
       }
   
       # Get to the right level
       if ( $self->{CURRENT_DEPTH} > $newDepth ) {
           push @{$self->{STACK}->[$newDepth]}, $here;
           $self->{CURRENT_DEPTH}--;
           return END_BRANCH();
       }
       if ( $self->{CURRENT_DEPTH} < $newDepth) {
           push @{$self->{STACK}->[$newDepth]}, $here;
           $self->{CURRENT_DEPTH}++;
           return BEGIN_BRANCH();
       }
   
       # If we made it here, we have the next resource, and we're at the
       # right branch level. So let's examine the resource for where
       # we can get to from here.
   
       # So we need to look at all the resources we can get to from here,
       # categorize them if we haven't seen them, remember if we have a new
       my $nextUnfiltered = $here->getNext();
   
       for (@$nextUnfiltered) {
           if (!defined($self->{ALREADY_SEEN}->{$_->{ID}})) {
               push @{$self->{STACK}->[$_->{DATA}->{DISPLAY_DEPTH}]}, $_;
               $self->{ALREADY_SEEN}->{$_->{ID}} = 1;
           }
       }
       
       # That ends the main iterator logic. Now, do we want to recurse
       # down this map (if this resource is a map)?
       if ($self->{HERE}->is_map() &&
           (defined($self->{FILTER}->{$self->{HERE}->map_pc()}) xor $self->{CONDITION})) {
           $self->{RECURSIVE_ITERATOR_FLAG} = 1;
           my $firstResource = $self->{HERE}->map_start();
           my $finishResource = $self->{HERE}->map_finish();
   
           $self->{RECURSIVE_ITERATOR} = 
               Apache::lonnavmaps::iterator->new($self->{NAV_MAP}, $firstResource,
                                                 $finishResource, $self->{FILTER},
                                                 $self->{ALREADY_SEEN}, $self->{CONDITION});
       }
   
       return $self->{HERE};
   
   }
   
   =pod
   
   The other method available on the iterator is B<getStack>, which returns an array populated with the current 'stack' of maps, as references to the resource objects. Example: This is useful when making the navigation map, as we need to check whether we are under a page map to see if we need to link directly to the resource, or to the page. The first elements in the array will correspond to the top of the stack (most inclusive map).
   
   =cut
   
   sub getStack {
       my $self=shift;
   
       my @stack;
   
       $self->populateStack(\@stack);
   
       return \@stack;
   }
   
   # Private method: Calls the iterators recursively to populate the stack.
   sub populateStack {
       my $self=shift;
       my $stack = shift;
   
       push @$stack, $self->{HERE} if ($self->{HERE});
   
       if ($self->{RECURSIVE_ITERATOR_FLAG}) {
           $self->{RECURSIVE_ITERATOR}->populateStack($stack);
       }
   }
   
   1;
   
   package Apache::lonnavmaps::DFSiterator;
   
   # UNDOCUMENTED: This is a private library, it should not generally be used
   # by the outside world. What it does is walk through the nav map in a 
   # depth-first fashion. This is not appropriate for most uses, but it is
   # used by the main iterator for pre-processing. It also is able to isolate
   # much of the complexity of the main iterator, so the main iterator is much
   # simpler.
   # There is no real benefit in merging the main iterator and this one into one class...
   # all the logic in DFSiterator would need to be replicated, you gain no performance,
   # at best, you just make one massively complicated iterator in place of two 
   # somewhat complicated ones. ;-) - Jeremy
   
   # Here are the tokens for the iterator, replicated from iterator for convenience:
   
   sub BEGIN_MAP { return 1; }    # begining of a new map
   sub END_MAP { return 2; }      # end of the map
   sub BEGIN_BRANCH { return 3; } # beginning of a branch
   sub END_BRANCH { return 4; }   # end of a branch
   sub FORWARD { return 1; }      # go forward
   sub BACKWARD { return 2; }
   
 # Params: nav map, start resource, end resource, filter, condition,   # Params: nav map, start resource, end resource, filter, condition, 
 # already seen hash ref  # already seen hash ref
Line 1433  sub new { Line 2344  sub new {
     # A hash, used as a set, of resource already seen      # A hash, used as a set, of resource already seen
     $self->{ALREADY_SEEN} = shift;      $self->{ALREADY_SEEN} = shift;
     if (!defined($self->{ALREADY_SEEN})) { $self->{ALREADY_SEEN} = {} };      if (!defined($self->{ALREADY_SEEN})) { $self->{ALREADY_SEEN} = {} };
       $self->{CONDITION} = shift;
       $self->{DIRECTION} = shift || FORWARD();
   
     # Flag: Have we started yet? If not, the first action is to return BEGIN_MAP.      # Flag: Have we started yet? If not, the first action is to return BEGIN_MAP.
     $self->{STARTED} = 0;      $self->{STARTED} = 0;
Line 1457  sub new { Line 2370  sub new {
     $self->{FORCE_NEXT} = undef;      $self->{FORCE_NEXT} = undef;
   
     # Start with the first resource      # Start with the first resource
     push @{$self->{BRANCH_STACK}}, $self->{FIRST_RESOURCE};      if ($self->{DIRECTION} == FORWARD) {
           push @{$self->{BRANCH_STACK}}, $self->{FIRST_RESOURCE};
       } else {
           push @{$self->{BRANCH_STACK}}, $self->{FINISH_RESOURCE};
       }
     $self->{BRANCH_STACK_SIZE} = 1;      $self->{BRANCH_STACK_SIZE} = 1;
   
     bless($self);      bless($self);
Line 1472  sub next { Line 2389  sub next {
           
     # Iterator logic goes here      # Iterator logic goes here
   
     # Is this return value pre-determined?  
     if (defined($self->{FORCE_NEXT})) {  
         my $tmp = $self->{FORCE_NEXT};  
         $self->{FORCE_NEXT} = undef;  
         return $tmp;  
     }  
   
     # Are we using a recursive iterator? If so, pull from that and      # Are we using a recursive iterator? If so, pull from that and
     # watch the depth; we want to resume our level at the correct time.      # watch the depth; we want to resume our level at the correct time.
     if ($self->{RECURSIVE_ITERATOR_FLAG})      if ($self->{RECURSIVE_ITERATOR_FLAG}) {
     {  
         # grab the next from the recursive iterator          # grab the next from the recursive iterator
         my $next = $self->{RECURSIVE_ITERATOR}->next();          my $next = $self->{RECURSIVE_ITERATOR}->next();
                   
Line 1498  sub next { Line 2407  sub next {
         return $next;          return $next;
     }      }
   
       # Is this return value pre-determined?
       if (defined($self->{FORCE_NEXT})) {
           my $tmp = $self->{FORCE_NEXT};
           $self->{FORCE_NEXT} = undef;
           return $tmp;
       }
   
     # Is there a current resource to grab? If not, then return      # Is there a current resource to grab? If not, then return
     # END_BRANCH and END_MAP in succession.      # END_BRANCH and END_MAP in succession.
     if (scalar(@{$self->{BRANCH_STACK}}) == 0) {      if (scalar(@{$self->{BRANCH_STACK}}) == 0) {
Line 1539  sub next { Line 2455  sub next {
   
     # Are we at the right depth? If not, close a branch and return      # Are we at the right depth? If not, close a branch and return
     # the current resource onto the branch stack      # the current resource onto the branch stack
       # Note: There seems to be some bugs here, so don't rely
       # on this, use the real iterator instead.
     if (defined($self->{HERE}->{DATA}->{ITERATOR_DEPTH})      if (defined($self->{HERE}->{DATA}->{ITERATOR_DEPTH})
         && $self->{HERE}->{DATA}->{ITERATOR_DEPTH} <          && $self->{HERE}->{DATA}->{ITERATOR_DEPTH} <
         $self->{BRANCH_DEPTH} ) {          $self->{BRANCH_DEPTH} ) {
Line 1553  sub next { Line 2471  sub next {
     # remember that we've seen this.      # remember that we've seen this.
     $self->{ALREADY_SEEN}->{$self->{HERE}->{ID}} = 1;      $self->{ALREADY_SEEN}->{$self->{HERE}->{ID}} = 1;
           
     # Are we at the utter end? If so, return the END_NAV_MAP marker.  
     if ($self->{HERE} == $self->{NAV_MAP}->finishResource() ) {  
         $self->{FORCE_NEXT} = $self->END_NAV_MAP;  
         return $self->{HERE};  
     }  
       
     # Get the next possible resources      # Get the next possible resources
     my $nextUnfiltered = $self->{HERE}->getNext();      my $nextUnfiltered;
       if ($self->{DIRECTION} == FORWARD()) {
           $nextUnfiltered = $self->{HERE}->getNext();
       } else {
           $nextUnfiltered = $self->{HERE}->getPrevious();
       }
     my $next = [];      my $next = [];
   
     # filter the next possibilities to remove things we've       # filter the next possibilities to remove things we've 
Line 1586  sub next { Line 2503  sub next {
             $self->{FORCE_NEXT} = $self->END_BRANCH();              $self->{FORCE_NEXT} = $self->END_BRANCH();
             $self->{BRANCH_DEPTH}--;              $self->{BRANCH_DEPTH}--;
         }          }
         return $self->{HERE};  
     }      }
           
     while (@$next) {      while (@$next) {
Line 1603  sub next { Line 2519  sub next {
   
     # If this is a map and we want to recurse down it... (not filtered out)      # If this is a map and we want to recurse down it... (not filtered out)
     if ($self->{HERE}->is_map() &&       if ($self->{HERE}->is_map() && 
          !defined($self->{FILTER}->{$self->{HERE}->map_pc()})) {            (defined($self->{FILTER}->{$self->{HERE}->map_pc()}) xor $self->{CONDITION})) { 
         $self->{RECURSIVE_ITERATOR_FLAG} = 1;          $self->{RECURSIVE_ITERATOR_FLAG} = 1;
         my $firstResource = $self->{HERE}->map_start();          my $firstResource = $self->{HERE}->map_start();
         my $finishResource = $self->{HERE}->map_finish();          my $finishResource = $self->{HERE}->map_finish();
   
         # Odd perl syntax here; $self->new allows one to create a new iterator  
         # can't figure out how to ref this package directly correctly  
         # isn't MAIN::new, __PACKAGE__::new or Apache::lonnavmaps::iterator->new  
         $self->{RECURSIVE_ITERATOR} =          $self->{RECURSIVE_ITERATOR} =
           Apache::lonnavmaps::iterator->new ($self->{NAV_MAP}, $firstResource,             Apache::lonnavmaps::DFSiterator->new ($self->{NAV_MAP}, $firstResource, 
                      $finishResource, $self->{FILTER}, $self->{ALREADY_SEEN});                       $finishResource, $self->{FILTER}, $self->{ALREADY_SEEN},
         # prime the new iterator with the first resource                                               $self->{CONDITION}, $self->{DIRECTION});
         #push @{$self->{RECURSIVE_ITERATOR}->{BRANCH_STACK}}, $firstResource;  
     }      }
   
     return $self->{HERE};      return $self->{HERE};
 }  }
   
 =pod  
   
 The other method available on the iterator is B<getStack>, which returns an array populated with the current 'stack' of maps, as references to the resource objects. Example: This is useful when making the navigation map, as we need to check whether we are under a page map to see if we need to link directly to the resource, or to the page. The first elements in the array will correspond to the top of the stack (most inclusive map).  
   
 =cut  
   
 sub getStack {  sub getStack {
     my $self=shift;      my $self=shift;
   
Line 1642  sub populateStack { Line 2548  sub populateStack {
     my $self=shift;      my $self=shift;
     my $stack = shift;      my $stack = shift;
   
     push @$stack, $self->{HERE};      push @$stack, $self->{HERE} if ($self->{HERE});
   
     if ($self->{RECURSIVE_ITERATOR_FLAG}) {      if ($self->{RECURSIVE_ITERATOR_FLAG}) {
         $self->{RECURSIVE_ITERATOR}->populateStack($stack);          $self->{RECURSIVE_ITERATOR}->populateStack($stack);
Line 1673  resource objects have a hash called DATA Line 2579  resource objects have a hash called DATA
   
 =over 4  =over 4
   
 =item * B<new>($navmapRef, $idString): The first arg is a reference to the parent navmap object. The second is the idString of the resource itself.   =item * B<new>($navmapRef, $idString): The first arg is a reference to the parent navmap object. The second is the idString of the resource itself. Very rarely, if ever, called directly. Use the nav map->getByID() method.
   
   =back
   
 =cut  =cut
   
Line 1688  sub new { Line 2596  sub new {
   
     # Store this new resource in the parent nav map's cache.      # Store this new resource in the parent nav map's cache.
     $self->{NAV_MAP}->{RESOURCE_CACHE}->{$self->{ID}} = $self;      $self->{NAV_MAP}->{RESOURCE_CACHE}->{$self->{ID}} = $self;
       $self->{RESOURCE_ERROR} = 0;
   
     # A hash that can be used by two-pass algorithms to store data      # A hash that can be used by two-pass algorithms to store data
     # about this resource in. Not used by the resource object      # about this resource in. Not used by the resource object
Line 1699  sub new { Line 2608  sub new {
     return $self;      return $self;
 }  }
   
 =pod  
   
 =item * B<is_map>: Returns true if this is a map, false otherwise.  
   
 =item * B<title>: Returns title.  
   
 =item * B<type>: Returns the type of the resource, "start", "normal", or "finish".   
   
 =item * B<problem>: Returns true if the resource is a problem type, false otherwise. (Looks at the extension on the src field.)  
   
 =back  
   
 =cut  
   
 # private function: simplify the NAV_HASH lookups we keep doing  # private function: simplify the NAV_HASH lookups we keep doing
 # pass the name, and to automatically append my ID, pass a true val on the  # pass the name, and to automatically append my ID, pass a true val on the
 # second param  # second param
Line 1723  sub navHash { Line 2618  sub navHash {
     return $self->{NAV_MAP}->{NAV_HASH}->{$param . ($id?$self->{ID}:"")};      return $self->{NAV_MAP}->{NAV_HASH}->{$param . ($id?$self->{ID}:"")};
 }  }
   
   =pod
   
   B<Metadata Retreival>
   
   These are methods that help you retrieve metadata about the resource:
   
   =over 4
   
   =item * B<ext>: Returns true if the resource is external.
   
   =item * B<goesto>: Returns the "goesto" value from the compiled nav map. (It is likely you want to use B<getNext> instead.)
   
   =item * B<kind>: Returns the kind of the resource from the compiled nav map.
   
   =item * B<randomout>: Returns true if this resource was chosen to NOT be shown to the user by the random map selection feature.
   
   =item * B<randompick>: Returns true for a map if the randompick feature is being used on the map. (?)
   
   =item * B<src>: Returns the source for the resource.
   
   =item * B<symb>: Returns the symb for the resource.
   
   =item * B<title>: Returns the title of the resource.
   
   =item * B<to>: Returns the "to" value from the compiled nav map. (It is likely you want to use B<getNext> instead.)
   
   =back
   
   =cut
   
 # These info functions can be used directly, as they don't return  # These info functions can be used directly, as they don't return
 # resource information.  # resource information.
 sub title { my $self=shift; return $self->navHash("title_", 1); }  sub comesfrom { my $self=shift; return $self->navHash("comesfrom_", 1); }
 sub type { my $self=shift; return $self->navHash("type_", 1); }  sub ext { my $self=shift; return $self->navHash("ext_", 1) eq 'true:'; }
   sub from { my $self=shift; return $self->navHash("from_", 1); }
 sub goesto { my $self=shift; return $self->navHash("goesto_", 1); }  sub goesto { my $self=shift; return $self->navHash("goesto_", 1); }
 # "to" can return a comma seperated list for branches  
 sub to { my $self=shift; return $self->navHash("to_", 1); }  
 sub kind { my $self=shift; return $self->navHash("kind_", 1); }  sub kind { my $self=shift; return $self->navHash("kind_", 1); }
   sub randomout { my $self=shift; return $self->navHash("randomout_", 1); }
   sub randompick { 
       my $self = shift;
       return $self->{NAV_MAP}->{PARM_HASH}->{$self->symb .
                                                  '.0.parameter_randompick'};
   }
 sub src {   sub src { 
     my $self=shift;      my $self=shift;
     return $self->navHash("src_", 1);      return $self->navHash("src_", 1);
Line 1743  sub symb { Line 2673  sub symb {
          $self->navHash('map_id_'.$first))            $self->navHash('map_id_'.$first)) 
         . '___' . $second . '___' . $symbSrc;          . '___' . $second . '___' . $symbSrc;
 }  }
 sub is_problem {  sub title { my $self=shift; return $self->navHash("title_", 1); }
   sub to { my $self=shift; return $self->navHash("to_", 1); }
   
   =pod
   
   B<Predicate Testing the Resource>
   
   These methods are shortcuts to deciding if a given resource has a given property.
   
   =over 4
   
   =item * B<is_map>: Returns true if the resource is a map type.
   
   =item * B<is_problem>: Returns true if the resource is a problem type, false otherwise. (Looks at the extension on the src field; might need more to work correctly.)
   
   =item * B<is_page>: Returns true if the resource is a page.
   
   =item * B<is_problem>: Returns true if the resource is a problem.
   
   =item * B<is_sequence>: Returns true if the resource sequence.
   
   =back
   
   =cut
   
   
   sub is_html {
     my $self=shift;      my $self=shift;
     my $src = $self->src();      my $src = $self->src();
     return ($src =~ /problem$/);      return ($src =~ /html$/);
 }  }
 sub is_html {  sub is_map { my $self=shift; return defined($self->navHash("is_map_", 1)); }
   sub is_page {
     my $self=shift;      my $self=shift;
     my $src = $self->src();      my $src = $self->src();
     return ($src =~ /html$/);      return ($src =~ /page$/);
 }  }
 sub is_sequence {  sub is_problem {
     my $self=shift;      my $self=shift;
     my $src = $self->src();      my $src = $self->src();
     return ($src =~ /sequence$/);      return ($src =~ /problem$/);
 }  }
 sub is_page {  sub is_sequence {
     my $self=shift;      my $self=shift;
     my $src = $self->src();      my $src = $self->src();
     return ($src =~ /page$/);      return ($src =~ /sequence$/);
 }  }
   
   
   
   
   
 # Move this into POD: In order to use these correctly, courseopt  # Move this into POD: In order to use these correctly, courseopt
 # and useropt need to be generated  # and useropt need to be generated
 sub parmval {  sub parmval {
Line 1776  sub parmval { Line 2734  sub parmval {
     return $self->{NAV_MAP}->parmval($part.'.'.$what, $self->symb());      return $self->{NAV_MAP}->parmval($part.'.'.$what, $self->symb());
 }  }
   
 #####  =pod
 # Map Queries  
 #####  
   
 # These methods relate to whether or not the resource is a map, and the   B<Map Methods>
 # attributes of that map.  
   These methods are useful for getting information about the map properties of the resource, if the resource is a map (B<is_map>).
   
   =over 4
   
   =item * B<map_finish>: Returns a reference to a resource object corresponding to the finish resource of the map.
   
   =item * B<map_pc>: Returns the pc value of the map, which is the first number that appears in the resource ID of the resources in the map, and is the number that appears around the middle of the symbs of the resources in that map.
   
   =item * B<map_start>: Returns a reference to a resource object corresponding to the start resource of the map.
   
   =item * B<map_type>: Returns a string with the type of the map in it.
   
   =back
   
   =cut
   
 sub is_map { my $self=shift; return defined($self->navHash("is_map_", 1)); }  
 sub map_finish {  sub map_finish {
     my $self = shift;      my $self = shift;
     my $src = $self->src();      my $src = $self->src();
Line 1791  sub map_finish { Line 2761  sub map_finish {
     $res = $self->{NAV_MAP}->getById($res);      $res = $self->{NAV_MAP}->getById($res);
     return $res;      return $res;
 }  }
   sub map_pc {
       my $self = shift;
       my $src = $self->src();
       return $self->navHash("map_pc_$src", 0);
   }
 sub map_start {  sub map_start {
     my $self = shift;      my $self = shift;
     my $src = $self->src();      my $src = $self->src();
Line 1798  sub map_start { Line 2773  sub map_start {
     $res = $self->{NAV_MAP}->getById($res);      $res = $self->{NAV_MAP}->getById($res);
     return $res;      return $res;
 }  }
 sub map_pc {  
     my $self = shift;  
     my $src = $self->src();  
     return $self->navHash("map_pc_$src", 0);  
 }  
 sub map_type {  sub map_type {
     my $self = shift;      my $self = shift;
     my $pc = $self->map_pc();      my $pc = $self->map_pc();
Line 1825  sub map_type { Line 2795  sub map_type {
   
 =head2 Resource Parameters  =head2 Resource Parameters
   
 In order to use the resource parameters correctly, the nav map must have been instantiated with genCourseAndUserOptions set to true, so the courseopt and useropt is read correctly. Then, you can call these functions to get the relevant parameters for the resource. Each function defaults to "part 0", but can be directed to another part by passing the part as the second parameter.  In order to use the resource parameters correctly, the nav map must have been instantiated with genCourseAndUserOptions set to true, so the courseopt and useropt is read correctly. Then, you can call these functions to get the relevant parameters for the resource. Each function defaults to part "0", but can be directed to another part by passing the part as the parameter.
   
 These methods are responsible for getting the parameter correct, not merely reflecting the contents of the GDBM hashes. As we move towards dates relative to other dates, these methods should be updated to reflect that. (Then, anybody using these methods won't have to update their code.)  These methods are responsible for getting the parameter correct, not merely reflecting the contents of the GDBM hashes. As we move towards dates relative to other dates, these methods should be updated to reflect that. (Then, anybody using these methods won't have to update their code.)
   
Line 1847  These methods are responsible for gettin Line 2817  These methods are responsible for gettin
   
 =item * B<tol>: Get the tolerance for the problem.  =item * B<tol>: Get the tolerance for the problem.
   
   =item * B<tries>: Get the number of tries the user has already used on the problem.
   
 =item * B<type>: Get the question type for the problem.  =item * B<type>: Get the question type for the problem.
   
 =item * B<weight>: Get the weight for the problem.  =item * B<weight>: Get the weight for the problem.
Line 1892  sub tol { Line 2864  sub tol {
     (my $self, my $part) = @_;      (my $self, my $part) = @_;
     return $self->parmval("tol", $part);      return $self->parmval("tol", $part);
 }  }
 sub type {  
     (my $self, my $part) = @_;  
     return $self->parmval("type", $part);  
 }  
 sub weight {  
     (my $self, my $part) = @_;  
     return $self->parmval("weight", $part);  
 }  
 sub tries {  sub tries {
     my $self = shift;      my $self = shift;
     my $part = shift;      my $part = shift;
Line 1912  sub tries { Line 2876  sub tries {
     if (!defined($tries)) {return '0';}      if (!defined($tries)) {return '0';}
     return $tries;      return $tries;
 }  }
   sub type {
       (my $self, my $part) = @_;
       return $self->parmval("type", $part);
   }
   sub weight {
       (my $self, my $part) = @_;
       return $self->parmval("weight", $part);
   }
   
 # Multiple things need this  # Multiple things need this
 sub getReturnHash {  sub getReturnHash {
     my $self = shift;      my $self = shift;
           
     if (!defined($self->{RETURN_HASH})) {      if (!defined($self->{RETURN_HASH})) {
         my %tmpHash = &Apache::lonnet::restore($self->symb());          my %tmpHash  = &Apache::lonnet::restore($self->symb());
         $self->{RETURN_HASH} = \%tmpHash;          $self->{RETURN_HASH} = \%tmpHash;
     }      }
 }         }       
Line 1945  Misc. functions for the resource. Line 2917  Misc. functions for the resource.
   
 =over 4  =over 4
   
 =item * B<parts>(): Returns a list reference containing sorted strings corresponding to each part of the problem. To count the number of parts, use the list in a scalar context, and subtract one if greater then two. (One part problems have a part 0. Multi-parts have a part 0, plus a part for each part. You may or may not wish to filter out part 0.)  =item * B<hasDiscussion>: Returns a false value if there has been discussion since the user last logged in, true if there has. Always returns false if the discussion data was not extracted when the nav map was constructed.
   
 =item * B<countParts>(): Returns the number of parts of the problem a student can answer. Thus, for single part problems, returns 1. For multipart, it returns the number of parts in the problem, not including psuedo-part 0.  =item * B<getFeedback>: Gets the feedback for the resource and returns the raw feedback string for the resource, or the null string if there is no feedback or the email data was not extracted when the nav map was constructed. Usually used like this:
   
    for (split(/\,/, $res->getFeedback())) {
       my $link = &Apache::lonnet::escape($_);
       ...
   
   and use the link as appropriate.
   
   =cut
   
   sub hasDiscussion {
       my $self = shift;
       return $self->{NAV_MAP}->hasDiscussion($self->symb());
   }
   
   sub getFeedback {
       my $self = shift;
       return $self->{NAV_MAP}->getFeedback($self->src());
   }
   
   =pod
   
   =item * B<parts>(): Returns a list reference containing sorted strings corresponding to each part of the problem. To count the number of parts, use the list in a scalar context, and subtract one if greater then two. (One part problems have a part 0. Multi-parts have a part 0, plus a part for each part. Filtering part 0 if you want it is up to you.)
   
   =item * B<countParts>(): Returns the number of parts of the problem a student can answer. Thus, for single part problems, returns 1. For multipart, it returns the number of parts in the problem, not including psuedo-part 0. Thus, B<parts> may return an array with fewer parts in it then countParts might lead you to believe.
   
 =back  =back
   
Line 1956  Misc. functions for the resource. Line 2952  Misc. functions for the resource.
 sub parts {  sub parts {
     my $self = shift;      my $self = shift;
   
       if ($self->ext) { return ['0']; }
   
     $self->extractParts();      $self->extractParts();
     return $self->{PARTS};      return $self->{PARTS};
 }  }
Line 1964  sub countParts { Line 2962  sub countParts {
     my $self = shift;      my $self = shift;
           
     my $parts = $self->parts();      my $parts = $self->parts();
       
     if (scalar(@{$parts}) == 1) { return 1;}      if ($self->{RESOURCE_ERROR}) {
           return 0;
       }
   
       if (scalar(@{$parts}) < 2) { return 1;}
   
     return scalar(@{$parts}) - 1;      return scalar(@{$parts}) - 1;
 }  }
Line 1975  sub extractParts { Line 2977  sub extractParts {
     my $self = shift;      my $self = shift;
           
     return if ($self->{PARTS});      return if ($self->{PARTS});
       return if ($self->ext);
   
     $self->{PARTS} = [];      $self->{PARTS} = [];
   
     # Retrieve part count      # Retrieve part count, if this is a problem
     foreach (split(/\,/,&Apache::lonnet::metadata($self->src(),       if ($self->is_problem()) {
                                                   'allpossiblekeys'))) {          my $metadata = &Apache::lonnet::metadata($self->src(), 'allpossiblekeys');
         if ($_ =~ /^parameter\_(.*)\_opendate$/) {          if (!$metadata) {
             push @{$self->{PARTS}}, $1;              $self->{RESOURCE_ERROR} = 1;
               $self->{PARTS} = [];
               return;
           }
           
           foreach (split(/\,/,$metadata)) {
               if ($_ =~ /^parameter\_(.*)\_opendate$/) {
                   push @{$self->{PARTS}}, $1;
               }
         }          }
           
           
           # Is this possible to do in one line? - Jeremy
           my @sortedParts = sort @{$self->{PARTS}};
           $self->{PARTS} = \@sortedParts;
     }      }
       
     # Is this possible to do in one line? - Jeremy  
     my @sortedParts = sort @{$self->{PARTS}};  
     $self->{PARTS} = \@sortedParts;  
   
     return;      return;
 }  }
Line 2007  Idiomatic usage of these two methods wou Line 3019  Idiomatic usage of these two methods wou
     my $dateStatus = $resource->getDateStatus($_);      my $dateStatus = $resource->getDateStatus($_);
     my $completionStatus = $resource->getCompletionStatus($_);      my $completionStatus = $resource->getCompletionStatus($_);
   
       or
   
       my $status = $resource->status($_);
   
     ... use it here ...      ... use it here ...
  }   }
   
 =over 4  =over 4
   
 =item * B<getDateStatus>($part): ($part defaults to 0). A convenience function that returns a symbolic constant telling you about the date status of the part, with the following possible results:  =item * B<getDateStatus>($part): ($part defaults to 0). A convenience function that returns a symbolic constant telling you about the date status of the part. The possible return values are:
   
 =back  =back
   
Line 2024  B<Date Codes> Line 3040  B<Date Codes>
   
 =item * B<OPEN>: Open and not yet due.  =item * B<OPEN>: Open and not yet due.
   
 =item * B<PAST_DUE>: The due date has passed, but the answer date has not yet arrived.  
   =item * B<PAST_DUE_ANSWER_LATER>: The due date has passed, but the answer date has not yet arrived.
   
   =item * B<PAST_DUE_NO_ANSWER>: The due date has passed and there is no answer opening date set.
   
 =item * B<ANSWER_OPEN>: The answer date is here.  =item * B<ANSWER_OPEN>: The answer date is here.
   
Line 2035  B<Date Codes> Line 3054  B<Date Codes>
 =cut  =cut
   
 # Apparently the compiler optimizes these into constants automatically  # Apparently the compiler optimizes these into constants automatically
 sub OPEN_LATER      { return 0; }  sub OPEN_LATER             { return 0; }
 sub OPEN            { return 1; }  sub OPEN                   { return 1; }
 sub PAST_DUE        { return 2; }  sub PAST_DUE_NO_ANSWER     { return 2; }
 sub ANSWER_OPEN     { return 3; }  sub PAST_DUE_ANSWER_LATER  { return 3; }
 sub NOTHING_SET     { return 4; }   sub ANSWER_OPEN            { return 4; }
 sub NETWORK_FAILURE { return 100; }  sub NOTHING_SET            { return 5; } 
   sub NETWORK_FAILURE        { return 100; }
   
   # getDateStatus gets the date status for a given problem part. 
   # Because answer date, due date, and open date are fully independent
   # (i.e., it is perfectly possible to *only* have an answer date), 
   # we have to completely cover the 3x3 maxtrix of (answer, due, open) x
   # (past, future, none given). This function handles this with a decision
   # tree. Read the comments to follow the decision tree.
   
 sub getDateStatus {  sub getDateStatus {
     my $self = shift;      my $self = shift;
     my $part = shift;      my $part = shift;
     $part = "0" if (!defined($part));      $part = "0" if (!defined($part));
   
       # Always return network failure if there was one.
     return $self->NETWORK_FAILURE if ($self->{NAV_MAP}->{NETWORK_FAILURE});      return $self->NETWORK_FAILURE if ($self->{NAV_MAP}->{NETWORK_FAILURE});
   
     my $now = time();      my $now = time();
Line 2054  sub getDateStatus { Line 3083  sub getDateStatus {
     my $due = $self->duedate($part);      my $due = $self->duedate($part);
     my $answer = $self->answerdate($part);      my $answer = $self->answerdate($part);
   
     if ($open && $now < $open) {return $self->OPEN_LATER};  
     if ($due && $now < $due) {return $self->OPEN};  
     if ($answer && $now < $answer) {return $self->PAST_DUE};  
     if (!$open && !$due && !$answer) {      if (!$open && !$due && !$answer) {
         # no data on the problem at all          # no data on the problem at all
         # should this be the same as "open later"? think multipart.          # should this be the same as "open later"? think multipart.
         return $self->NOTHING_SET;          return $self->NOTHING_SET;
     }      }
     return $self->ANSWER_OPEN;      if (!$open || $now < $open) {return $self->OPEN_LATER}
       if (!$due || $now < $due) {return $self->OPEN}
       if ($answer && $now < $answer) {return $self->PAST_DUE_ANSWER_LATER}
       if ($answer) { return $self->ANSWER_OPEN; }
       return PAST_DUE_NO_ANSWER;
 }  }
   
 =pod  =pod
Line 2093  B<Completion Codes> Line 3123  B<Completion Codes>
   
 =item * B<NETWORK_FAILURE>: Information not available due to network failure.  =item * B<NETWORK_FAILURE>: Information not available due to network failure.
   
   =item * B<ATTEMPTED>: Attempted, and not yet graded.
   
 =back  =back
   
 =cut  =cut
Line 2103  sub INCORRECT_BY_OVERRIDE { return 12; } Line 3135  sub INCORRECT_BY_OVERRIDE { return 12; }
 sub CORRECT               { return 13; }  sub CORRECT               { return 13; }
 sub CORRECT_BY_OVERRIDE   { return 14; }  sub CORRECT_BY_OVERRIDE   { return 14; }
 sub EXCUSED               { return 15; }  sub EXCUSED               { return 15; }
   sub ATTEMPTED             { return 16; }
   
 sub getCompletionStatus {  sub getCompletionStatus {
     my $self = shift;      my $self = shift;
Line 2121  sub getCompletionStatus { Line 3154  sub getCompletionStatus {
     if ($status eq 'incorrect_attempted') {return $self->INCORRECT; }      if ($status eq 'incorrect_attempted') {return $self->INCORRECT; }
     if ($status eq 'incorrect_by_override') {return $self->INCORRECT_BY_OVERRIDE; }      if ($status eq 'incorrect_by_override') {return $self->INCORRECT_BY_OVERRIDE; }
     if ($status eq 'excused') {return $self->EXCUSED; }      if ($status eq 'excused') {return $self->EXCUSED; }
       if ($status eq 'ungraded_attempted') {return $self->ATTEMPTED; }
     return $self->NOT_ATTEMPTED;      return $self->NOT_ATTEMPTED;
 }  }
   
Line 2132  Along with directly returning the date o Line 3166  Along with directly returning the date o
   
 =over 4  =over 4
   
 =item * NETWORK_FAILURE: The network has failed and the information is not available.  =item * B<NETWORK_FAILURE>: The network has failed and the information is not available.
   
   =item * B<NOTHING_SET>: No dates have been set for this problem (part) at all. (Because only certain parts of a multi-part problem may be assigned, this can not be collapsed into "open later", as we don't know a given part will EVER be opened. For single part, this is the same as "OPEN_LATER".)
   
   =item * B<CORRECT>: For any reason at all, the part is considered correct.
   
 =item * NOTHING_SET: No dates have been set for this problem (part) at all. (Because only certain parts of a multi-part problem may be assigned, this can not be collapsed into "open later", as we don't know a given part will EVER be opened.)  =item * B<EXCUSED>: For any reason at all, the problem is excused.
   
 =item * CORRECT: For any reason at all, the part is considered correct.  =item * B<PAST_DUE_NO_ANSWER>: The problem is past due, not considered correct, and no answer date is set.
   
 =item * EXCUSED: For any reason at all, the problem is excused.  =item * B<PAST_DUE_ANSWER_LATER>: The problem is past due, not considered correct, and an answer date in the future is set.
   
 =item * PAST_DUE: The problem is past due, and not considered correct.  =item * B<ANSWER_OPEN>: The problem is past due, not correct, and the answer is now available.
   
 =item * ANSWER_OPEN: The problem is past due, not correct, and the answer is now available.  =item * B<OPEN_LATER>: The problem is not yet open.
   
 =item * OPEN_LATER: The problem is not yet open.  =item * B<TRIES_LEFT>: The problem is open, has been tried, is not correct, but there are tries left.
   
 =item * TRIES_LEFT: The problem is open, has been tried, is not correct, but there are tries left.  =item * B<INCORRECT>: The problem is open, and all tries have been used without getting the correct answer.
   
 =item * INCORRECT: The problem is open, and all tries have been used without getting the correct answer.  =item * B<OPEN>: The item is open and not yet tried.
   
 =item * OPEN: The item is open and not yet tried.  =item * B<ATTEMPTED>: The problem has been attempted.
   
 =back  =back
   
Line 2167  sub status { Line 3205  sub status {
   
     # What we have is a two-dimensional matrix with 4 entries on one      # What we have is a two-dimensional matrix with 4 entries on one
     # dimension and 5 entries on the other, which we want to colorize,      # dimension and 5 entries on the other, which we want to colorize,
     # plus network failure and "no date data".      # plus network failure and "no date data at all".
   
     if ($completionStatus == NETWORK_FAILURE) { return NETWORK_FAILURE; }      if ($completionStatus == NETWORK_FAILURE) { return NETWORK_FAILURE; }
   
     # There are a few whole rows we can dispose of:      # There are a few whole rows we can dispose of:
     if ($completionStatus == CORRECT ||      if ($completionStatus == CORRECT ||
         $completionStatus == CORRECT_BY_OVERRIDE ) {          $completionStatus == CORRECT_BY_OVERRIDE ) {
         return CORRECT();           return CORRECT; 
       }
   
       if ($completionStatus == ATTEMPTED) {
           return ATTEMPTED;
     }      }
   
     # If it's EXCUSED, then return that no matter what      # If it's EXCUSED, then return that no matter what
Line 2186  sub status { Line 3228  sub status {
         return NOTHING_SET;          return NOTHING_SET;
     }      }
   
     # Now we're down to a 3 (incorrect, incorrect_override, not_attempted)      # Now we're down to a 4 (incorrect, incorrect_override, not_attempted)
     # by 4 matrix (date status).      # by 4 matrix (date statuses).
   
     if ($dateStatus == PAST_DUE) {      if ($dateStatus == PAST_DUE_ANSWER_LATER ||
         return PAST_DUE;           $dateStatus == PAST_DUE_NO_ANSWER ) {
           return $dateStatus; 
     }      }
   
     if ($dateStatus == ANSWER_OPEN) {      if ($dateStatus == ANSWER_OPEN) {
Line 2207  sub status { Line 3250  sub status {
     # If it's WRONG...      # If it's WRONG...
     if ($completionStatus == INCORRECT || $completionStatus == INCORRECT_BY_OVERRIDE) {      if ($completionStatus == INCORRECT || $completionStatus == INCORRECT_BY_OVERRIDE) {
         # and there are TRIES LEFT:          # and there are TRIES LEFT:
         if ($self->tries() < $self->maxtries()) {          if ($self->tries($part) < $self->maxtries($part) || !$self->maxtries($part)) {
             return TRIES_LEFT;              return TRIES_LEFT;
         }          }
         return INCORRECT; # otherwise, return orange; student can't fix this          return INCORRECT; # otherwise, return orange; student can't fix this
Line 2223  sub status { Line 3266  sub status {
   
 =over 4  =over 4
   
 =item * B<getNext>(): Gets the next resource in the navmap after this one.  =item * B<getNext>($alreadySeenHashRef): Retreive an array of the possible next resources after this one. Always returns an array, even in the one- or zero-element case. The "alreadySeenHashRef" is an optional parameter that can be passed in to the method. If $$alreadySeenHashRef{$res->id()} is true in that hash, getNext will not return it in the list. In other words, you can use it to suppress resources you've already seen in the getNext method directly.
   
 =cut  =item * B<getPrevious>($alreadySeenHashRef): Retreive an array of the possible previous resources from this one. Always returns an array, even in the one- or zero-element case. $alreadySeenHashRef is the same as in getNext.
   
 # For the simple single-link case, to get from a resource to the next  =cut
 # resource, you need to look up the "to_" link in the nav hash, then  
 # follow that with the "goesto_" link.  
   
 sub getNext {  sub getNext {
     my $self = shift;      my $self = shift;
     my $alreadySeenHash = shift;      my $alreadySeenHash = shift;
     my @branches;      my @branches;
     my $to = $self->to();      my $to = $self->to();
     foreach my $branch ( split(/\,/, $to) ) {      foreach my $branch ( split(/,/, $to) ) {
         my $choice = $self->{NAV_MAP}->getById($branch);          my $choice = $self->{NAV_MAP}->getById($branch);
         my $next = $choice->goesto();          my $next = $choice->goesto();
         $next = $self->{NAV_MAP}->getById($next);          $next = $self->{NAV_MAP}->getById($next);
   
         # Don't remember it if we've already seen it          # Don't remember it if we've already seen it or if
           # the student doesn't have browse priviledges
           my $browsePriv = &Apache::lonnet::allowed('bre', $self->src);
         if (!defined($alreadySeenHash) ||          if (!defined($alreadySeenHash) ||
             !defined($alreadySeenHash->{$next->{ID}})) {              !defined($alreadySeenHash->{$next->{ID}}) ||
               ($browsePriv ne '2' && $browsePriv ne 'F')) {
                 push @branches, $next;                  push @branches, $next;
             }              }
     }      }
     return \@branches;      return \@branches;
 }  }
   
   sub getPrevious {
       my $self = shift;
       my $alreadySeenHash = shift;
       my @branches;
       my $from = $self->from();
       foreach my $branch ( split /,/, $from) {
           my $choice = $self->{NAV_MAP}->getById($branch);
           my $prev = $choice->comesfrom();
           $prev = $self->{NAV_MAP}->getById($prev);
   
           # Skip it if we've already seen it or the user doesn't have
           # browse privs
           my $browsePriv = &Apache::lonnet::allowed('bre', $self->src);
           if (!defined($alreadySeenHash) ||
               !defined($alreadySeenHash->{$prev->{ID}}) ||
               ($browsePriv ne '2' && $browsePriv ne 'F')) {
               push @branches, $prev;
           }
       }
       return \@branches;
   }
   
 =pod  =pod
   

Removed from v.1.53  
changed lines
  Added in v.1.98


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