# The LearningOnline Network with CAPA
# Search Catalog
#
# $Id: lonsearchcat.pm,v 1.125 2002/06/20 19:43:50 matthew Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
# YEAR=2001
# 3/8, 3/12, 3/13, 3/14, 3/15, 3/19 Scott Harrison
# 3/20, 3/21, 3/22, 3/26, 3/27, 4/2, 8/15, 8/24, 8/25 Scott Harrison
# 10/12,10/14,10/15,10/16,11/28,11/29,12/10,12/12,12/16 Scott Harrison
# YEAR=2002
# 1/17 Scott Harrison
# 6/17 Matthew Hall
#
###############################################################################
###############################################################################

=pod 

=head1 NAME

lonsearchcat

=head1 SYNOPSIS

Search interface to LON-CAPAs digital library

=head1 DESCRIPTION

This module enables searching for a distributed browseable catalog.

This is part of the LearningOnline Network with CAPA project
described at http://www.lon-capa.org.

lonsearchcat presents the user with an interface to search the LON-CAPA
digital library.  lonsearchcat also initiates the execution of a search
by sending the search parameters to LON-CAPA servers.  The progress of 
search (on a server basis) is displayed to the user in a seperate window.

=head1 Internals

=over 4

=cut

###############################################################################
###############################################################################

##                                                                           ##
## ORGANIZATION OF THIS PERL MODULE                                          ##
##                                                                           ##
## 1. Modules used by this module                                            ##
## 2. Choices for different output views (detailed, summary, xml, etc)       ##
## 3. BEGIN block (to be run once after compilation)                         ##
## 4. Handling routine called via Apache and mod_perl                        ##
## 5. Other subroutines                                                      ##
##                                                                           ##
###############################################################################

package Apache::lonsearchcat;

# ------------------------------------------------- modules used by this module
use strict;
use Apache::Constants qw(:common);
use Apache::lonnet();
use Apache::File();
use CGI qw(:standard);
use Text::Query;
use GDBM_File;
use Apache::loncommon();

# ---------------------------------------- variables used throughout the module

######################################################################
######################################################################

=pod 

=item Global variables

=over 4

=item %hostdomains

matches host name to host domain

=item %hostips

matches host name to host ip

=item %hitcount

stores number of hits per host

=item $closebutton

button that closes the search window

=item $importbutton

button to take the selecte results and go to group sorting

=item %hash   

The ubiquitous database hash

=item $diropendb 

The full path to the (temporary) search database file.  This is set and
used in &handler() and is also used in &output_results().

=back 

=cut

######################################################################
######################################################################

# -- information holders
my %hostdomains; # matches host name to host domain
my %hostips;     # matches host name to host ip
my %hitcount;    # stores number of hits per host

# -- dynamically rendered interface components
my $closebutton;  # button that closes the search window
my $importbutton; # button to take the selected results and go to group sorting

# -- miscellaneous variables
my $yourself; # allows for quickly limiting to oneself
my %hash;     # database hash

# ------------------------------------------ choices for different output views
# Detailed Citation View ---> sub detailed_citation_view
# Summary View ---> sub summary_view
# Fielded Format ---> sub fielded_format_view
# XML/SGML ---> sub xml_sgml_view

#------------------------------------------------------------- global variables
my $diropendb = "";
my $domain = "";

# ----------------------------------------------------------------------- BEGIN

=pod

=item BEGIN block

Load %hostdomains and %hostips with data from lonnet.pm.  Only library
servers are considered.

=cut

BEGIN {
    foreach (keys (%Apache::lonnet::libserv)) {
        $hostdomains{$_}=$Apache::lonnet::hostdom{$_};
        $hostips{$_}=$Apache::lonnet::hostip{$_};
    }
}

######################################################################
######################################################################

=pod 

=item &handler() - main handler invoked by httpd child

=item Variables

=over 4

=item $hidden

holds 'hidden' html forms

=item $scrout

string that holds portions of the screen output

=back 

=cut

######################################################################
######################################################################
sub handler {
    my $r = shift;
    untie %hash;

    $r->content_type('text/html');
    $r->send_http_header;
    return OK if $r->header_only;

    my $domain  = $r->dir_config('lonDefDomain');
    $diropendb= "/home/httpd/perl/tmp/".&Apache::lonnet::escape($domain).
            "\_".&Apache::lonnet::escape($ENV{'user.name'})."_searchcat.db";

    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
             ['catalogmode','launch','acts','mode','form','element',
              'reqinterface']);
    ##
    ## Clear out old values from database
    ##
    if ($ENV{'form.launch'} eq '1') {
	if (tie(%hash,'GDBM_File',$diropendb,&GDBM_WRCREAT,0640)) {
	    &start_fresh_session();
	    untie %hash;
	} else {
	    $r->print('<html><head></head><body>Unable to tie hash to db '.
		      'file</body></html>');
	    return OK;
	}
    }
    ##
    ## Produce some output, so people know it is working
    ##
    $r->print("\n");
    $r->rflush;
    ##
    ## Configure dynamic components of interface
    ##
    my $hidden;       # Holds 'hidden' html forms
    if ($ENV{'form.catalogmode'} eq 'interactive') {
	$hidden="<input type='hidden' name='catalogmode' value='interactive'>".
	    "\n";
        $closebutton="<input type='button' name='close' value='CLOSE' ".
	    "onClick='self.close()'>"."\n";
    } elsif ($ENV{'form.catalogmode'} eq 'groupsearch') {
	$hidden=<<END;
<input type='hidden' name='catalogmode' value='groupsearch'>
END
        $closebutton=<<END;
<input type='button' name='close' value='CLOSE' onClick='self.close()'>
END
        $importbutton=<<END;
<input type='button' name='import' value='IMPORT'
onClick='javascript:select_group()'>
END
    }
    $hidden .= <<END;
<input type='hidden' name='mode'    value='$ENV{'form.mode'}'>
<input type='hidden' name='form'    value='$ENV{'form.form'}'>
<input type='hidden' name='element' value='$ENV{'form.element'}'>
<input type='hidden' name='date' value='2'>
END
    ##
    ##  What are we doing?
    ##
    if ($ENV{'form.basicsubmit'} eq 'SEARCH') {
        # Perform basic search and give results
	return &basicsearch($r,\%ENV,$hidden);
    } elsif ($ENV{'form.advancedsubmit'} eq 'SEARCH') {
        # Perform advanced search and give results
	return &advancedsearch($r,\%ENV,$hidden);
    } elsif ($ENV{'form.reqinterface'} eq 'advanced') {
        # Output the advanced interface
        $r->print(&advanced_search_form($closebutton,$hidden));
        return OK;
    } else { 
        # Output normal search interface
        $r->print(&basic_search_form($closebutton,$hidden));
    }
    return OK;
} 

######################################################################
######################################################################

=pod 

=item &basic_search_form() 

Returns a scalar which holds html for the basic search form.

=cut

######################################################################
######################################################################

sub basic_search_form{
    my ($closebutton,$hidden) = @_;
    my $scrout=<<"ENDDOCUMENT";
<html>
<head>
<title>The LearningOnline Network with CAPA</title>
<script type="text/javascript">
    function openhelp(val) {
	openhelpwin=open('/adm/help/searchcat.html','helpscreen',
	     'scrollbars=1,width=600,height=300');
	openhelpwin.focus();
    }
</script>
</head>
<body bgcolor="#FFFFFF">
<img align='right' src='/adm/lonIcons/lonlogos.gif' />
<h1>Search Catalog</h1>
<form method="post" action="/adm/searchcat">
$hidden
<h3>Basic Search</h3>
<p>
Enter terms or phrases separated by AND, OR, or NOT then press SEARCH below.
</p>
<p>
<table>
<tr><td>
ENDDOCUMENT
    $scrout.='&nbsp;'.&simpletextfield('basicexp',$ENV{'form.basicexp'},40).
        '&nbsp;';
#    $scrout.=&simplecheckbox('allversions',$ENV{'form.allversions'});
#    $scrout.='<font color="#800000">Search historic archives</font>';
    $scrout.=<<ENDDOCUMENT;
</td><td><a href="/adm/searchcat?reqinterface=advanced">Advanced Search</a></td></tr></table>
</p>
<p>
&nbsp;<input type="submit" name="basicsubmit" value='SEARCH' />&nbsp;
$closebutton
<!-- basic view selection -->
<select name='basicviewselect'>
<option value='Detailed Citation View' selected="true">
Detailed Citation View</option>
<option value='Summary View'>Summary View</option>
<option value='Fielded Format'>Fielded Format</option>
<option value='XML/SGML'>XML/SGML</option>
</select>
<!-- end of basic view selection -->
<input type="button" value="HELP" onClick="openhelp()" />
</p>
</form>
</body>
</html>
ENDDOCUMENT
    return $scrout;
}
######################################################################
######################################################################

=pod 

=item &advanced_search_form() 

Returns a scalar which holds html for the advanced search form.

=cut

######################################################################
######################################################################

sub advanced_search_form{
    my ($closebutton,$hidden) = @_;
    my $scrout=<<"ENDHEADER";
<html>
<head>
<title>The LearningOnline Network with CAPA</title>
<script type="text/javascript">
    function openhelp(val) {
	openhelpwin=open('/adm/help/searchcat.html','helpscreen',
	     'scrollbars=1,width=600,height=300');
	openhelpwin.focus();
    }
</script>
</head>
<body bgcolor="#FFFFFF">
<img align='right' src='/adm/lonIcons/lonlogos.gif' />
<h1>Search Catalog</h1>
<form method="post" action="/adm/searchcat">
$hidden
<hr />
<h3>Advanced Search</h3>
ENDHEADER
    $scrout.=&searchphrasefield('Limit by title','title',
			$ENV{'form.title'});
    $scrout.=&searchphrasefield('Limit by author','author',
			$ENV{'form.author'});
    $scrout.=&searchphrasefield('Limit by subject','subject',
			$ENV{'form.subject'});
    $scrout.=&searchphrasefield('Limit by keywords','keywords',
			$ENV{'form.keywords'});
    $scrout.=&searchphrasefield('Limit by URL','url',
			$ENV{'form.url'});
#    $scrout.=&searchphrasefield('Limit by version','version',
#			$ENV{'form.version'});
    $scrout.=&searchphrasefield('Limit by notes','notes',
			$ENV{'form.notes'});
    $scrout.=&searchphrasefield('Limit by abstract','abstract',
			$ENV{'form.abstract'});
    $ENV{'form.mime'}='any' unless length($ENV{'form.mime'});
    $scrout.=&selectbox('Limit by MIME type','mime',
			$ENV{'form.mime'},
			'any','Any type',
			\&{Apache::loncommon::filedescriptionex},
			(&Apache::loncommon::fileextensions));
    $ENV{'form.language'}='any' unless length($ENV{'form.language'});
    $scrout.=&selectbox('Limit by language','language',
			$ENV{'form.language'},'any','Any Language',
			\&{Apache::loncommon::languagedescription},
			(&Apache::loncommon::languageids),
			);
# ------------------------------------------------ Compute date selection boxes
    $scrout.=<<CREATIONDATESTART;
<p>
<font color="#800000" face="helvetica"><b>LIMIT BY CREATION DATE RANGE:</b>
</font>
<br />
between:
CREATIONDATESTART
    $scrout.=&dateboxes('creationdatestart',1,1,1976,
			$ENV{'form.creationdatestart_month'},
			$ENV{'form.creationdatestart_day'},
			$ENV{'form.creationdatestart_year'},
			);
    $scrout.="and:\n";
    $scrout.=&dateboxes('creationdateend',12,31,2051,
			$ENV{'form.creationdateend_month'},
			$ENV{'form.creationdateend_day'},
			$ENV{'form.creationdateend_year'},
			);
    $scrout.="</p>";
    $scrout.=<<LASTREVISIONDATESTART;
<p>
<font color="#800000" face="helvetica"><b>LIMIT BY LAST REVISION DATE RANGE:
</b></font>
<br />between:
LASTREVISIONDATESTART
    $scrout.=&dateboxes('lastrevisiondatestart',1,1,1976,
			$ENV{'form.lastrevisiondatestart_month'},
			$ENV{'form.lastrevisiondatestart_day'},
			$ENV{'form.lastrevisiondatestart_year'},
			);
    $scrout.=<<LASTREVISIONDATEEND;
and:
LASTREVISIONDATEEND
    $scrout.=&dateboxes('lastrevisiondateend',12,31,2051,
			$ENV{'form.lastrevisiondateend_month'},
			$ENV{'form.lastrevisiondateend_day'},
			$ENV{'form.lastrevisiondateend_year'},
			);
    $scrout.='</p>';
    $scrout.=&searchphrasefield('Limit by publisher/owner','owner',
				$ENV{'form.owner'});
    $ENV{'form.copyright'}='any' unless length($ENV{'form.copyright'});
    $scrout.=&selectbox('Limit by copyright/distribution','copyright',
			 $ENV{'form.copyright'},
			 'any','Any copyright/distribution',
			 \&{Apache::loncommon::copyrightdescription},
			 (&Apache::loncommon::copyrightids),
			 );
# ------------------------------------------- Compute customized metadata field
    $scrout.=<<CUSTOMMETADATA;
<p>
<font color="#800000" face="helvetica"><b>LIMIT BY SPECIAL METADATA FIELDS:</b>
</font>
For resource-specific metadata, enter in an expression in the form of 
<i>key</i>=<i>value</i> separated by operators such as AND, OR or NOT.<br />
<b>Example:</b> grandmother=75 OR grandfather=85
<br />
CUSTOMMETADATA
    $scrout.=&simpletextfield('custommetadata',$ENV{'form.custommetadata'});
    $scrout.=<<CUSTOMSHOW;
<p>
<font color="#800000" face="helvetica"><b>SHOW SPECIAL METADATA FIELDS:</b>
</font>
Enter in a space-separated list of special metadata fields to show
in a fielded listing for each record result.
<br />
CUSTOMSHOW
    $scrout.=&simpletextfield('customshow',$ENV{'form.customshow'});
    $scrout.=<<ENDDOCUMENT;
<p>
<input type="submit" name="advancedsubmit" value='SEARCH' />
<input type="reset" name="reset" value='RESET' />
$closebutton
<!-- advance view select -->
<select name='advancedviewselect'>
<option value='Detailed Citation View' selected="true">
Detailed Citation View</option>
<option value='Summary View'>Summary View</option>
<option value='Fielded Format'>Fielded Format</option>
<option value='XML/SGML'>XML/SGML</option>
</select>
<!-- end of advanced view select -->
<input type="button" value="HELP" onClick="openhelp()" />
</p>
</form>
</body>
</html>
ENDDOCUMENT
    return $scrout;
}

######################################################################
######################################################################

=pod 

=item &make_persistent() 

Returns a scalar which holds the current ENV{'form.*'} values in
a 'hidden' html input tag.  

=cut

######################################################################
######################################################################

sub make_persistent {
    my $persistent='';
    foreach (keys %ENV) {
	if (/^form\./ && !/submit/) {
	    my $name=$_;
	    my $key=$name;
	    $ENV{$key}=~s/\'//g; # do not mess with html field syntax
	    $name=~s/^form\.//;
	    $persistent.=<<END;
<input type="hidden" name="$name" value="$ENV{$key}" />
END
        }
    }
    return $persistent;
}


######################################################################
######################################################################

=pod 

=item HTML form building functions

=over 4

=item &simpletextfield() 

Inputs: $name,$value,$size

Returns a text input field with the given name, value, and size.  
If size is not specified, a value of 20 is used.

=item &simplecheckbox()

Inputs: $name,$value

Returns a simple check box with the given $name.
If $value eq 'on' the box is checked.

=item &searchphrasefield()

Inputs: $title,$name,$value

Returns html for a title line and an input field for entering search terms.
the instructions "Enter terms or phrases separated by search operators such 
as AND, OR, or NOT." are given following the title.  The entry field (which
is where the $name and $value are used) is an 80 column simpletextfield.

=item &dateboxes()

=item &selectbox()

=back 

=cut

######################################################################
######################################################################

sub simpletextfield {
    my ($name,$value,$size)=@_;
    $size = 20 if (! defined($size));
    return '<input type="text" name="'.$name.
        '" size="'.$size.'" value="'.$value.'" />';
}

sub simplecheckbox {
    my ($name,$value)=@_;
    my $checked='';
    $checked="CHECKED" if $value eq 'on';
    return '<input type="checkbox" name="'.$name.'" '. $checked . ' />';
}

sub searchphrasefield {
    my ($title,$name,$value)=@_;
    my $instruction=<<END;
Enter terms or phrases separated by search operators such as AND, OR, or NOT.
END
    my $uctitle=uc($title);
    return "\n".
        '<p><font color="#800000" face="helvetica"><b>'.$uctitle.':</b>'.
        "</FONT> $instruction<br />".&simpletextfield($name,$value,80);
}

sub dateboxes {
    my ($name,$defaultmonth,$defaultday,$defaultyear,
	$currentmonth,$currentday,$currentyear)=@_;
    ($defaultmonth,$defaultday,$defaultyear)=('','','');
    #
    # Day
    my $day=<<END;
<select name="${name}_day">
<option value='$defaultday'> </option>
END
    for (my $i = 1; $i<=31; $i++) {
	$day.="<option value=\"$i\">$i</option>\n";
    }
    $day.="</select>\n";
    $day=~s/(\"$currentday\")/$1 SELECTED/ if length($currentday);
    #
    # Month
    my $month=<<END;
<select name="${name}_month">
<option value='$defaultmonth'> </option>
END
    my $i = 1;
    foreach (qw/January February March April May June 
	     July August September October November December /){
	$month .="<option value=\"$i\">$_</option>\n";
	$i++;
    }
    $month.="</select>\n";
    $month=~s/(\"$currentmonth\")/$1 SELECTED/ if length($currentmonth);
    #
    # Year (obviously)
    my $year=<<END;
<select name="${name}_year">
<option value='$defaultyear'> </option>
END
    my $maxyear = 2051; 
    for (my $i = 1976; $i<=$maxyear; $i++) {
	$year.="<option value=\"$i\">$i</option>\n";
    }
    $year.="</select>\n";
    $year=~s/(\"$currentyear\")/$1 SELECTED/ if length($currentyear);
    return "$month$day$year";
}

sub selectbox {
    my ($title,$name,$value,$anyvalue,$anytag,$functionref,@idlist)=@_;
    my $uctitle=uc($title);
    my $selout="\n".'<p><font color="#800000" face="helvetica">'.
        '<b>'.$uctitle.':</b></font><br /><select name="'.$name.'">';
    foreach ($anyvalue,@idlist) {
        $selout.='<option value="'.$_.'"';
        if ($_ eq $value and !/^any$/) {
	    $selout.=' selected >'.&{$functionref}($_).'</option>';
	}
	elsif ($_ eq $value and /^$anyvalue$/) {
	    $selout.=' selected >'.$anytag.'</option>';
	}
        else {$selout.='>'.&{$functionref}($_).'</option>';}
    }
    return $selout.'</select>';
}

######################################################################
######################################################################

=pod 

=item &advancedsearch() 

=cut

######################################################################
######################################################################
sub advancedsearch {
    my ($r,$envhash,$hidden)=@_;
    my %ENV=%{$envhash};
    my $fillflag=0;
    # Clean up fields for safety
    for my $field ('title','author','subject','keywords','url','version',
		   'creationdatestart_month','creationdatestart_day',
		   'creationdatestart_year','creationdateend_month',
		   'creationdateend_day','creationdateend_year',
		   'lastrevisiondatestart_month','lastrevisiondatestart_day',
		   'lastrevisiondatestart_year','lastrevisiondateend_month',
		   'lastrevisiondateend_day','lastrevisiondateend_year',
		   'notes','abstract','mime','language','owner',
		   'custommetadata','customshow') {
	$ENV{"form.$field"}=~s/[^\w\/\s\(\)\=\-\"\']//g;
    }
    foreach ('mode','form','element') {
	# is this required?  Hmmm.
	next unless (exists($ENV{"form.$_"}));
	$ENV{"form.$_"}=&Apache::lonnet::unescape($ENV{"form.$_"});
	$ENV{"form.$_"}=~s/[^\w\/\s\(\)\=\-\"\']//g;
    }
    # Check to see if enough information was filled in
    for my $field ('title','author','subject','keywords','url','version',
		   'notes','abstract','mime','language','owner',
		   'custommetadata') {
	if (&filled($ENV{"form.$field"})) {
	    $fillflag++;
	}
    }
    unless ($fillflag) {
	&output_blank_field_error($r);
	return OK;
    }
    # Turn the form input into a SQL-based query
    my $query='';
    my @queries;
    # Evaluate logical expression AND/OR/NOT phrase fields.
    foreach my $field ('title','author','subject','notes','abstract','url',
		       'keywords','version','owner') {
	if ($ENV{'form.'.$field}) {
	    push @queries,&build_SQL_query($field,$ENV{'form.'.$field});
	}
    }
    # Evaluate option lists
    if ($ENV{'form.language'} and $ENV{'form.language'} ne 'any') {
	push @queries,"(language like \"$ENV{'form.language'}\")";
    }
    if ($ENV{'form.mime'} and $ENV{'form.mime'} ne 'any') {
	push @queries,"(mime like \"$ENV{'form.mime'}\")";
    }
    if ($ENV{'form.copyright'} and $ENV{'form.copyright'} ne 'any') {
	push @queries,"(copyright like \"$ENV{'form.copyright'}\")";
    }
    # Evaluate date windows
    my $datequery=&build_date_queries(
			$ENV{'form.creationdatestart_month'},
			$ENV{'form.creationdatestart_day'},
			$ENV{'form.creationdatestart_year'},
			$ENV{'form.creationdateend_month'},
			$ENV{'form.creationdateend_day'},
			$ENV{'form.creationdateend_year'},
			$ENV{'form.lastrevisiondatestart_month'},
			$ENV{'form.lastrevisiondatestart_day'},
			$ENV{'form.lastrevisiondatestart_year'},
			$ENV{'form.lastrevisiondateend_month'},
			$ENV{'form.lastrevisiondateend_day'},
			$ENV{'form.lastrevisiondateend_year'},
			);
    # Test to see if date windows are legitimate
    if ($datequery=~/^Incorrect/) {
	&output_date_error($r,$datequery);
	return OK;
    }
    elsif ($datequery) {
	push @queries,$datequery;
    }
    # Process form information for custom metadata querying
    my $customquery='';
    if ($ENV{'form.custommetadata'}) {
	$customquery=&build_custommetadata_query('custommetadata',
				      $ENV{'form.custommetadata'});
    }
    my $customshow='';
    if ($ENV{'form.customshow'}) {
	$customshow=$ENV{'form.customshow'};
	$customshow=~s/[^\w\s]//g;
	my @fields=split(/\s+/,$customshow);
	$customshow=join(" ",@fields);
    }
    # Send query statements over the network to be processed by either the SQL
    # database or a recursive scheme of 'grep'-like actions (for custom
    # metadata).
    if (@queries) {
	$query=join(" AND ",@queries);
	$query="select * from metadata where $query";
	my $reply; # reply hash reference
	unless ($customquery or $customshow) {
	    $reply=&Apache::lonnet::metadata_query($query);
	}
	else {
	    $reply=&Apache::lonnet::metadata_query($query,
						   $customquery,$customshow);
	}
	&output_results('Advanced',$r,$envhash,$customquery,$reply,$hidden);
    }
    elsif ($customquery) {
	my $reply; # reply hash reference
	$reply=&Apache::lonnet::metadata_query('',
					       $customquery,$customshow);
	&output_results('Advanced',$r,$envhash,$customquery,$reply,$hidden);
    }
    # should not get to this point
    return 'Error.  Should not have gone to this point.';
}

######################################################################
######################################################################

=pod 

=item &basicsearch() 

=cut

######################################################################
######################################################################
sub basicsearch {
    my ($r,$envhash,$hidden)=@_;
    my %ENV=%{$envhash};
    # Clean up fields for safety
    for my $field ('basicexp') {
	$ENV{"form.$field"}=~s/[^\w\s\(\)\-]//g;
    }
    foreach ('mode','form','element') {
	# is this required?  Hmmm.
	next unless (exists($ENV{"form.$_"}));
	$ENV{"form.$_"}=&Apache::lonnet::unescape($ENV{"form.$_"});
	$ENV{"form.$_"}=~s/[^\w\/\s\(\)\=\-\"\']//g;
    }

    # Check to see if enough is filled in
    unless (&filled($ENV{'form.basicexp'})) {
	&output_blank_field_error($r);
	return OK;
    }

    # Build SQL query string based on form page
    my $query='';
    my $concatarg=join(',"    ",',
		       ('title', 'author', 'subject', 'notes', 'abstract',
                        'keywords'));
    $concatarg='title' if $ENV{'form.titleonly'};

    $query=&build_SQL_query('concat('.$concatarg.')',$ENV{'form.'.'basicexp'});

    # Get reply (either a hash reference to filehandles or bad connection)
    my $reply=&Apache::lonnet::metadata_query('select * from metadata where '.$query);

    # Output search results

    &output_results('Basic',$r,$envhash,$query,$reply,$hidden);

    return OK;
}


######################################################################
######################################################################

=pod 

=item &build_SQL_query() 

=cut

######################################################################
######################################################################
sub build_SQL_query {
    my ($field_name,$logic_statement)=@_;
    my $q=new Text::Query('abc',
			  -parse => 'Text::Query::ParseAdvanced',
			  -build => 'Text::Query::Build');
    $q->prepare($logic_statement);
    my $matchexp=${$q}{'matchexp'}; chomp $matchexp;
    my $sql_query=&recursive_SQL_query_build($field_name,$matchexp);
    return $sql_query;
}

######################################################################
######################################################################

=pod 

=item &build_custommetadata_query() 

=cut

######################################################################
######################################################################
sub build_custommetadata_query {
    my ($field_name,$logic_statement)=@_;
    &Apache::lonnet::logthis("Entered build_custommetadata_query:".
                             $field_name.':'.$logic_statement);
    my $q=new Text::Query('abc',
			  -parse => 'Text::Query::ParseAdvanced',
			  -build => 'Text::Query::BuildAdvancedString');
    $q->prepare($logic_statement);
    my $matchexp=${$q}{'-parse'}{'-build'}{'matchstring'};
    # quick fix to change literal into xml tag-matching
    # will eventually have to write a separate builder module
    # wordone=wordtwo becomes\<wordone\>[^\<] *wordtwo[^\<]*\<\/wordone\>
    $matchexp =~ s/(\w+)\\=([\w\\\+]+)?# wordone=wordtwo is changed to 
                 /\\<$1\\>?#           \<wordone\>
                   \[\^\\<\]?#        [^\<]         
                   \*$2\[\^\\<\]?#           *wordtwo[^\<]
                   \*\\<\\\/$1\\>?#                        *\<\/wordone\>
                   /g;
    &Apache::lonnet::logthis("match expression: ".$matchexp);
    return $matchexp;
}

######################################################################
######################################################################

=pod 

=item &recursive_SQL_query_build() 

=cut

######################################################################
######################################################################
sub recursive_SQL_query_build {
    my ($dkey,$pattern)=@_;
    my @matches=($pattern=~/(\[[^\]|\[]*\])/g);
    return $pattern unless @matches;
    foreach my $match (@matches) {
	$match=~/\[ (\w+)\s(.*) \]/;
	my ($key,$value)=($1,$2);
	my $replacement='';
	if ($key eq 'literal') {
	    $replacement="($dkey like \"\%$value\%\")";
	}
	elsif ($key eq 'not') {
	    $value=~s/like/not like/;
#	    $replacement="($dkey not like $value)";
	    $replacement="$value";
	}
	elsif ($key eq 'and') {
	    $value=~/(.*[\"|\)]) ([|\(|\^].*)/;
	    $replacement="($1 AND $2)";
	}
	elsif ($key eq 'or') {
	    $value=~/(.*[\"|\)]) ([|\(|\^].*)/;
	    $replacement="($1 OR $2)";
	}
	substr($pattern,
	       index($pattern,$match),
	       length($match),
	       $replacement
	       );
    }
    &recursive_SQL_query_build($dkey,$pattern);
}

######################################################################
######################################################################

=pod 

=item &build_date_queries() 

=cut

######################################################################
######################################################################
sub build_date_queries {
    my ($cmonth1,$cday1,$cyear1,$cmonth2,$cday2,$cyear2,
	$lmonth1,$lday1,$lyear1,$lmonth2,$lday2,$lyear2)=@_;
    my @queries;
    if ($cmonth1 or $cday1 or $cyear1 or $cmonth2 or $cday2 or $cyear2) {
	unless ($cmonth1 and $cday1 and $cyear1 and
		$cmonth2 and $cday2 and $cyear2) {
	    return "Incorrect entry for the creation date.  You must specify ".
		   "a starting month, day, and year and an ending month, ".
		   "day, and year.";
	}
	my $cnumeric1=sprintf("%d%2d%2d",$cyear1,$cmonth1,$cday1);
	$cnumeric1+=0;
	my $cnumeric2=sprintf("%d%2d%2d",$cyear2,$cmonth2,$cday2);
	$cnumeric2+=0;
	if ($cnumeric1>$cnumeric2) {
	    return "Incorrect entry for the creation date.  The starting ".
		   "date must occur before the ending date.";
	}
	my $cquery="(creationdate BETWEEN '$cyear1-$cmonth1-$cday1' AND '".
	           "$cyear2-$cmonth2-$cday2 23:59:59')";
	push @queries,$cquery;
    }
    if ($lmonth1 or $lday1 or $lyear1 or $lmonth2 or $lday2 or $lyear2) {
	unless ($lmonth1 and $lday1 and $lyear1 and
		$lmonth2 and $lday2 and $lyear2) {
	    return "Incorrect entry for the last revision date.  You must ".
		   "specify a starting month, day, and year and an ending ".
		   "month, day, and year.";
	}
	my $lnumeric1=sprintf("%d%2d%2d",$lyear1,$lmonth1,$lday1);
	$lnumeric1+=0;
	my $lnumeric2=sprintf("%d%2d%2d",$lyear2,$lmonth2,$lday2);
	$lnumeric2+=0;
	if ($lnumeric1>$lnumeric2) {
	    return "Incorrect entry for the last revision date.  The ".
		   "starting date must occur before the ending date.";
	}
	my $lquery="(lastrevisiondate BETWEEN '$lyear1-$lmonth1-$lday1' AND '".
	           "$lyear2-$lmonth2-$lday2 23:59:59')";
	push @queries,$lquery;
    }
    if (@queries) {
	return join(" AND ",@queries);
    }
    return '';
}

######################################################################
######################################################################

=pod 

=item &output_results() 

Format and output results based on a reply list.
There are two windows that this function writes to.  The main search
window ("srch") has a listing of the results.  A secondary window ("popwin")
gives the status of the network search (time elapsed, number of machines
contacted, etc.)

=cut

######################################################################
######################################################################
sub output_results {
    my $fnum; # search result counter
    my ($mode,$r,$envhash,$query,$replyref,$hidden)=@_;
    my %ENV=%{$envhash};
    my %rhash=%{$replyref};
    my $compiledresult='';
    my $timeremain=300; # (seconds)
    my $elapsetime=0;
    my $resultflag=0;
    my $tflag=1;
    #
    # make query information persistent to allow for subsequent revision
    my $persistent=&make_persistent();
    # spit out the generic header
    $r->print(&search_results_header());
    $r->rflush();
    # begin showing the cataloged results
    $r->print(<<CATALOGBEGIN);
</head>
<body bgcolor="#ffffff">
<img align=right src=/adm/lonIcons/lonlogos.gif>
<h1>Search Catalog</h1>
CATALOGBEGIN
        $r->print(<<CATALOGCONTROLS);
<form name='results' method="post" action="/adm/searchcat">
$hidden
<input type='hidden' name='acts' value='' />
<input type='button' value='Revise search request'
onClick='this.form.submit();' />
$importbutton
$closebutton
$persistent
<hr />
<h3>Search Query</h3>
CATALOGCONTROLS
    #
    # Remind them what they searched for
    #
    if ($mode eq 'Basic') {
	$r->print('<p><b>Basic search:</b> '.$ENV{'form.basicexp'}.'</p>');
    } elsif ($mode eq 'Advanced') {
	$r->print('<p><b>Advanced search</b> '.$query.'</p>');
    }
    $r->print('<h3>Search Results</h3>');
    $r->rflush();
    #
    # make the pop-up window for status
    #
    $r->print(&make_popwin(%rhash));
    $r->rflush();
    ##
    ## Prepare for the main loop below
    ##
    my $servercount=0;
    my $hitcountsum=0;
    my $servernum=(keys %rhash);
    my $serversleft=$servernum;
    ##
    ## Run until we run out of time or we run out of servers
    ##
    while($serversleft && $timeremain) {
      ##
      ## %rhash has servers deleted from it as results come in 
      ## (within the foreach loop below).
      ##
      foreach my $rkey (sort keys %rhash) {
	$servercount++;
	$tflag=1;
	$compiledresult='';
	my $hostname=$rkey;
	my $reply=$rhash{$rkey};
	my @results;
	if ($reply eq 'con_lost') {
	    &popwin_imgupdate($r,$rkey,"srvbad.gif");
	    $serversleft--;
            delete $rhash{$rkey};
	} else {
            # must do since 'use strict' checks for tainting
	    $reply=~/^([\.\w]+)$/; 
	    my $replyfile=$r->dir_config('lonDaemons').'/tmp/'.$1;
	    $reply=~/(.*?)\_/;
	    {
		my $temp=0;
	      WLOOP: while (1) {
		  if (-e $replyfile && $tflag) {
		      &popwin_imgupdate($r,$rkey,"srvhalf.gif");
		      &popwin_js($r,'popwin.hc["'.$rkey.'"]='.
				 '"still transferring..."'.';');
		      $tflag=0;
		  }
		  if (-e "$replyfile.end") {
		      $serversleft--;
                      delete $rhash{$rkey};
		      if (-s $replyfile) {
			  &popwin_imgupdate($r,$rkey,"srvgood.gif");
			  my $fh=Apache::File->new($replyfile) or 
			      ($r->print('ERROR: file '.
					 $replyfile.' cannot be opened') and
			       return OK);
			  @results=<$fh> if $fh;
			  $hitcount{$rkey}=@results+0;
			  &popwin_js($r,'popwin.hc["'.$rkey.'"]='.
				    $hitcount{$rkey}.';');
			  $hitcountsum+=$hitcount{$rkey};
			  &popwin_js($r,'popwin.document.forms.popremain.'.
				    'numhits.value='.$hitcountsum.';');
		      }
		      else {
			  &popwin_imgupdate($r,$rkey,"srvempty.gif");
			  &popwin_js($r,'popwin.hc["'.$rkey.'"]=0;');
		      }
		      last WLOOP;
		  } # end of if ( -e "$replyfile.end")
		  last WLOOP unless $timeremain;
		  sleep 1;    # wait for daemons to write files?
		  $timeremain--;
		  $elapsetime++;
		  last WLOOP if ($temp>1);
		  &popwin_js($r,"popwin.document.popremain.".
			       "elapsetime.value=$elapsetime;");
		  $temp++;
	      }
	    }
	    &popwin_js($r,'popwin.document.whirly.'.
		       'src="/adm/lonIcons/lonanimend.gif";');
	} # end of if ($reply eq 'con_lost') else statement
	my $customshow='';
	my $extrashow='';
	my @customfields;
	if ($ENV{'form.customshow'}) {
	    $customshow=$ENV{'form.customshow'};
	    $customshow=~s/[^\w\s]//g;
	    my @fields=map {"<font color=\"#008000\">$_:</font><!-- $_ -->"} 
	    split(/\s+/,$customshow);
	    @customfields=split(/\s+/,$customshow);
	    if ($customshow) {
		$extrashow="<ul><li>".join("</li><li>",@fields)."</li></ul>\n";
	    }
	}
	my $customdata='';
	my %customhash;
	foreach my $result (@results) {
	    if ($result=~/^(custom\=.*)$/) { # grab all custom metadata
		my $tmp=$result;
		$tmp=~s/^custom\=//;
		my ($k,$v)=map {&Apache::lonnet::unescape($_);
			    } split(/\,/,$tmp);
		$customhash{$k}=$v;
	    }
	}
	if (keys %hash) {
	    untie %hash;
	}
	if (tie(%hash,'GDBM_File',$diropendb,&GDBM_WRCREAT,0640)) {
	    if ($ENV{'form.launch'} eq '1') {
		&start_fresh_session();
	    }
	    foreach my $result (@results) {
		next if $result=~/^custom\=/;
		chomp $result;
		next unless $result;
		my @fields=map
		{&Apache::lonnet::unescape($_)}
		(split(/\,/,$result));
		my ($title,$author,$subject,$url,$keywords,$version,
		    $notes,$abstract,$mime,$lang,
		    $creationdate,$lastrevisiondate,$owner,$copyright)=@fields;
                unless ($title =~ /^\s*$/ ) { $title='<i>Untitled</i>'; }
		unless ($ENV{'user.adv'}) {
		    $keywords='<i>- not displayed -</i>';
		    $fields[4]=$keywords;
		    $notes='<i>- not displayed -</i>';
		    $fields[6]=$notes;
		    $abstract='<i>- not displayed -</i>';
		    $fields[7]=$abstract;
		    $subject='<i>- not displayed -</i>';
		    $fields[2]=$subject;
		}

		my $shortabstract=$abstract;
		$shortabstract=substr($abstract,0,200).'...' if length($abstract)>200;
		$fields[7]=$shortabstract;
		my $shortkeywords=$keywords;
		$shortkeywords=substr($keywords,0,200).'...' if length($keywords)>200;
		$fields[4]=$shortkeywords;

		my $extrashow2=$extrashow;
		if ($extrashow) {
		    foreach my $field (@customfields) {
			my $value='';
			if ($customhash{$url}=~/\<${field}[^\>]*\>(.*?)\<\/${field}[^\>]*\>/s) {
		            $value=$1;
			}
		        $extrashow2=~s/\<\!\-\- $field \-\-\>/ $value/g;
	            }
                }
	
	        $compiledresult.=<<END if $compiledresult or $servercount!=$servernum;
<hr align='left' width='200' noshade />
END
                $compiledresult.=<<END;
<p>
END
               if ($ENV{'form.catalogmode'} eq 'interactive') {
		   my $titleesc=$title;
		   $titleesc=~s/\'/\\'/; # '

                   $compiledresult.=<<END if ($ENV{'form.catalogmode'} eq 'interactive');
<font size='-1'><INPUT TYPE="button" NAME="returnvalues" VALUE="SELECT"
onClick="javascript:select_data('$titleesc','$url')">
</font>
<br />
END
                }
                if ($ENV{'form.catalogmode'} eq 'groupsearch') {
		    $fnum+=0;
		    $hash{"pre_${fnum}_link"}=$url;
		    $hash{"pre_${fnum}_title"}=$title;
		    $compiledresult.=<<END;
<font size='-1'>
<input type="checkbox" name="returnvalues" value="SELECT"
onClick="javascript:queue($fnum)" />
</font>
<br />
END
# <input type="hidden" name="title$fnum" value="$title" />
# <input type="hidden" name="url$fnum" value="$url" />
                    $fnum++;
		}
	        my $httphost=$ENV{'HTTP_HOST'};

	        my $viewselect;
	        if ($mode eq 'Basic') {
		    $viewselect=$ENV{'form.basicviewselect'};
		}
	        elsif ($mode eq 'Advanced') {
		    $viewselect=$ENV{'form.advancedviewselect'};
		}

	        if ($viewselect eq 'Detailed Citation View') {
		    $compiledresult.=&detailed_citation_view(@fields,
						 $hostname,$httphost,
						 $extrashow2);
		}
                elsif ($viewselect eq 'Summary View') {
		    $compiledresult.=&summary_view(@fields,$hostname,$httphost,
				       $extrashow2);
	        }
                elsif ($viewselect eq 'Fielded Format') {
		    $compiledresult.=&fielded_format_view(@fields,$hostname,
					      $httphost,$extrashow2);
	        }
                elsif ($viewselect eq 'XML/SGML') {
		    $compiledresult.=&xml_sgml_view(@fields,$hostname,$httphost,
					$extrashow2);
		}
    
            }

            untie %hash;
        }
        else {
	    $r->print('<html><head></head><body>Unable to tie hash to db '.
		  'file</body></html>');
	}
	if ($compiledresult) {
	    $resultflag=1;
	}

	$r->print(<<RESULTS);
$compiledresult
RESULTS
        my $percent=sprintf('%3.0f',($servercount/$servernum*100));
    }
  }
    unless ($resultflag) {
        $r->print("\nThere were no results that matched your query\n");
    }
#    $r->print('<script type="text/javascript">'.'popwin.close()</script>'."\n"); $r->rflush(); 
    $r->print(<<RESULTS);
</body>
</html>
RESULTS
}

######################################################################
######################################################################

=pod

=item &search_results_header

=cut

######################################################################
######################################################################
sub search_results_header {
    my $result = '';
    # output beginning of search page
    $result.=<<BEGINNING;
<html>
<head>
<title>The LearningOnline Network with CAPA</title>
BEGINNING
    # conditional output of script functions dependent on the mode in
    # which the search was invoked
    if ($ENV{'form.catalogmode'} eq 'interactive'){
	if (! exists($ENV{'form.mode'}) || $ENV{'form.mode'} ne 'edit') {
            $result.=<<SCRIPT;
<script type="text/javascript">
    function select_data(title,url) {
	changeTitle(title);
	changeURL(url);
	self.close();
    }
    function changeTitle(val) {
	if (opener.inf.document.forms.resinfo.elements.t) {
	    opener.inf.document.forms.resinfo.elements.t.value=val;
	}
    }
    function changeURL(val) {
	if (opener.inf.document.forms.resinfo.elements.u) {
	    opener.inf.document.forms.resinfo.elements.u.value=val;
	}
    }
</script>
SCRIPT
        } elsif ($ENV{'form.mode'} eq 'edit') {
            my $form = $ENV{'form.form'};
            my $element = $ENV{'form.element'};
            $result.=<<SCRIPT;
<script type="text/javascript">
function select_data(title,url) {
    changeURL(url);
    self.close();
}
function changeTitle(val) {
}
function changeURL(val) {
    if (window.opener.document) {
        window.opener.document.forms["$form"].elements["$element"].value=val;
    } else {
	var url = 'forms[\"$form\"].elements[\"$element\"].value';
        alert("Unable to transfer data to "+url);
    }
}
</script>
SCRIPT
        }
    }
    $result.=<<SCRIPT if $ENV{'form.catalogmode'} eq 'groupsearch';
<script type="text/javascript">
    function select_data(title,url) {
//	alert('DEBUG: Should be storing '+title+' and '+url);
    }
    function queue(val) {
	if (eval("document.forms.results.returnvalues["+val+"].checked")) {
	    document.forms.results.acts.value+='1a'+val+'b';
	}
	else {
	    document.forms.results.acts.value+='0a'+val+'b';
	}
    }
    function select_group() {
	window.location=
    "/adm/groupsort?mode=$ENV{'form.mode'}&catalogmode=groupsearch&acts="+
	    document.forms.results.acts.value;
    }
</script>
SCRIPT
    $result.=<<SCRIPT;
<script type="text/javascript">
    function displayinfo(val) {
	popwin.document.forms.popremain.sdetails.value=val;
    }
    function openhelp(val) {
	openhelpwin=open('/adm/help/searchcat.html','helpscreen',
	     'scrollbars=1,width=400,height=300');
	openhelpwin.focus();
    }
    function abortsearch(val) {
	popwin.close();
    }
</script>
SCRIPT
    return $result;
}

######################################################################
######################################################################

=pod

=item &make_popwin()

Returns html with javascript in it to open up the status window.

=cut

######################################################################
######################################################################
sub make_popwin {
    my %rhash = @_;
    my $servernum=(keys %rhash);
    my $hcinit;
    my $grid="'<br />'+\n";
    # $sn is the server number, used ONLY to make sure we have
    # rows of 10 each.  No longer used to index images.
    my $sn=1;
    foreach my $sk (sort keys %rhash) {
	# '<a href="
	$grid.="'<a href=\"";
	# javascript:displayinfo('+
	$grid.="javascript:opener.displayinfo('+";
	# "'"+'key
	$grid.="\"'\"+'";
	$grid.=$sk;
	my $hc;
	if ($rhash{$sk} eq 'con_lost') {
	    $hc="BAD CONNECTION, CONTACT SYSTEM ADMINISTRATOR ";
	}
	else {
	    $hc="'+\"'\"+\"+hc['$sk']+\"+\"'\"+'";
	    $hcinit.="hc[\"$sk\"]=\"not yet connected...\";";
	}
	$grid.=" hitcount=".$hc;
	$grid.=" domain=".$hostdomains{$sk};
	$grid.=" IP=".$hostips{$sk};
	# '+"'"+'">'+
	$grid.="'+\"'\"+')\">'+";
	$grid.="\n";
	$grid.="'<img border=\"0\" name=\"img_".$hostdomains{$sk}.'_'.$sk."\"".
	    " src=\"/adm/lonIcons/srvnull.gif\" alt=\"".$sk."\" /></a>'+\n";
	$grid.="'<br />'+\n" unless $sn%10;
        $sn++;
    }
    my $result.=<<ENDPOP;
<script type="text/javascript">
    popwin=open('','popwin','scrollbars=1,width=400,height=220');
    popwin.focus();
    popwin.document.writeln('<'+'html>');
    popwin.document.writeln('<'+'head>');
    popwin.document.writeln('<'+'script>');
    popwin.document.writeln('hc=new Array();$hcinit');
    popwin.document.writeln('<'+'/script>');
    popwin.document.writeln('<'+'/head>'+
        '<'+'body bgcolor="#FFFFFF">'+
	'<'+'image name="whirly" align="right" src="/adm/lonIcons/'+
	'lonanim.gif" '+
	'alt="animated logo" />'+
	'<'+'h3>Search Results Progress<'+'/h3>'+
        '<'+'form name="popremain">'+
        '<'+'tt>'+
	'<'+'br clear="all"/><i>PLEASE BE PATIENT</i>'+
	'<'+'br />SCANNING $servernum SERVERS'+
	'<'+'br clear="all" />Number of record hits found '+
	'<'+'input type="text" size="10" name="numhits"'+
	' value="0" />'+
	'<'+'br clear="all" />Time elapsed '+
	'<'+'input type="text" size="10" name="elapsetime"'+
	' value="0" />'+
	'<'+'br />'+
	'SERVER GRID (click on any cell for details)'+
        $grid
        '<'+'br />'+
	'Server details '+
	'<'+'input type="text" size="35" name="sdetails"'+
	' value="" />'+
	'<'+'br />'+
	' <'+'input type="button" name="button"'+
	' value="close this window" '+
	' onClick="javascript:opener.abortsearch()" />'+
	' <'+'input type="button" name="button"'+
	' value="help" onClick="javascript:opener.openhelp()" />'+
	'<'+'/tt>'+
        '<'+'/form>'+
        '<'+'/body><'+'/html>');
    popwin.document.close();
</script>
ENDPOP
    return $result;
}

######################################################################
######################################################################

=pod 

=item Metadata Viewing Functions

Output is a HTML-ified string.
Input arguments are title, author, subject, url, keywords, version,
notes, short abstract, mime, language, creation date,
last revision date, owner, copyright, hostname, httphost, and
extra custom metadata to show.

=over 4

=item &detailed_citation_view() 

=cut

######################################################################
######################################################################
sub detailed_citation_view {
    my ($title,$author,$subject,$url,$keywords,$version,
	$notes,$shortabstract,$mime,$lang,
	$creationdate,$lastrevisiondate,$owner,$copyright,
	$hostname,$httphost,$extrashow)=@_;
    my $result=<<END;
<i>$owner</i>, last revised $lastrevisiondate
<h3><A HREF="http://$httphost$url" TARGET='search_preview'>$title</A></h3>
<h3>$author</h3>
</p>
<p>
<b>Subject:</b> $subject<br />
<b>Keyword(s):</b> $keywords<br />
<b>Notes:</b> $notes<br />
<b>MIME Type:</b>
END
    $result.=&Apache::loncommon::filedescription($mime);
    $result.=<<END;
<br />
<b>Language:</b> 
END
    $result.=&Apache::loncommon::languagedescription($lang);
    $result.=<<END;
<br />
<b>Copyright/Distribution:</b> 
END
    $result.=&Apache::loncommon::copyrightdescription($copyright);
    $result.=<<END;
<br />
</p>
$extrashow
<p>
$shortabstract
</p>
END
    return $result;
}

######################################################################
######################################################################

=pod 

=item &summary_view() 

=cut

######################################################################
######################################################################
sub summary_view {
    my ($title,$author,$subject,$url,$keywords,$version,
	$notes,$shortabstract,$mime,$lang,
	$creationdate,$lastrevisiondate,$owner,$copyright,
	$hostname,$httphost,$extrashow)=@_;
    my $cprtag=&Apache::loncommon::copyrightdescription($copyright);
    my $result=<<END;
<a href="http://$httphost$url" TARGET='search_preview'>$author</a><br />
$title<br />
$owner -- $lastrevisiondate<br />
$cprtag<br />
$extrashow
</p>
END
    return $result;
}

######################################################################
######################################################################

=pod 

=item &fielded_format_view() 

=cut

######################################################################
######################################################################
sub fielded_format_view {
    my ($title,$author,$subject,$url,$keywords,$version,
	$notes,$shortabstract,$mime,$lang,
	$creationdate,$lastrevisiondate,$owner,$copyright,
	$hostname,$httphost,$extrashow)=@_;
    my $mimetag=&Apache::loncommon::filedescription($mime);
    my $language=&Apache::loncommon::languagedescription($lang);
    my $cprtag=&Apache::loncommon::copyrightdescription($copyright);
    my $result=<<END;
<b>URL: </b> <A HREF="http://$httphost$url" TARGET='search_preview'>$url</A>
<br />
<b>Title:</b> $title<br />
<b>Author(s):</b> $author<br />
<b>Subject:</b> $subject<br />
<b>Keyword(s):</b> $keywords<br />
<b>Notes:</b> $notes<br />
<b>MIME Type:</b> $mimetag<br />
<b>Language:</b> $language<br />
<b>Creation Date:</b> $creationdate<br />
<b>Last Revision Date:</b> $lastrevisiondate<br />
<b>Publisher/Owner:</b> $owner<br />
<b>Copyright/Distribution:</b> $cprtag<br />
<b>Repository Location:</b> $hostname<br />
<b>Abstract:</b> $shortabstract<br />
$extrashow
</p>
END
    return $result;
}

######################################################################
######################################################################

=pod 

=item &xml_sgml_view() 

=back 

=cut

######################################################################
######################################################################
sub xml_sgml_view {
    my ($title,$author,$subject,$url,$keywords,$version,
	$notes,$shortabstract,$mime,$lang,
	$creationdate,$lastrevisiondate,$owner,$copyright,
	$hostname,$httphost,$extrashow)=@_;
    my $cprtag=&Apache::loncommon::copyrightdescription($copyright);
    my $mimetag=&Apache::loncommon::filedescription($mime);
    my $language=&Apache::loncommon::languagedescription($lang);
    my $result=<<END;
<pre>
&lt;LonCapaResource&gt;
&lt;url&gt;$url&lt;/url&gt;
&lt;title&gt;$title&lt;/title&gt;
&lt;author&gt;$author&lt;/author&gt;
&lt;subject&gt;$subject&lt;/subject&gt;
&lt;keywords&gt;$keywords&lt;/keywords&gt;
&lt;notes&gt;$notes&lt;/notes&gt;
&lt;mimeInfo&gt;
&lt;mime&gt;$mime&lt;/mime&gt;
&lt;mimetag&gt;$mimetag&lt;/mimetag&gt;
&lt;/mimeInfo&gt;
&lt;languageInfo&gt;
&lt;language&gt;$lang&lt;/language&gt;
&lt;languagetag&gt;$language&lt;/languagetag&gt;
&lt;/languageInfo&gt;
&lt;creationdate&gt;$creationdate&lt;/creationdate&gt;
&lt;lastrevisiondate&gt;$lastrevisiondate&lt;/lastrevisiondate&gt;
&lt;owner&gt;$owner&lt;/owner&gt;
&lt;copyrightInfo&gt;
&lt;copyright&gt;$copyright&lt;/copyright&gt;
&lt;copyrighttag&gt;$cprtag&lt;/copyrighttag&gt;
&lt;/copyrightInfo&gt;
&lt;repositoryLocation&gt;$hostname&lt;/repositoryLocation&gt;
&lt;shortabstract&gt;$shortabstract&lt;/shortabstract&gt;
&lt;/LonCapaResource&gt;
</pre>
$extrashow
END
    return $result;
}

######################################################################
######################################################################

=pod 

=item &filled() see if field is filled.

=cut

######################################################################
######################################################################
sub filled {
    my ($field)=@_;
    if ($field=~/\S/ && $field ne 'any') {
	return 1;
    }
    else {
	return 0;
    }
}

######################################################################
######################################################################

=pod 

=item &output_blank_field_error()

=cut

######################################################################
######################################################################
sub output_blank_field_error {
    my ($r)=@_;
    # make query information persistent to allow for subsequent revision
    my $persistent=&make_persistent();

    $r->print(<<BEGINNING);
<html>
<head>
<title>The LearningOnline Network with CAPA</title>
BEGINNING
    $r->print(<<RESULTS);
</head>
<body bgcolor="#ffffff">
<img align='right' src='/adm/lonIcons/lonlogos.gif' />
<h1>Search Catalog</h1>
<form method="post" action="/adm/searchcat">
$persistent
<input type='button' value='Revise search request'
onClick='this.form.submit();' />
$closebutton
<hr />
<h3>Helpful Message</h3>
<p>
Incorrect search query due to blank entry fields.
You need to fill in the relevant
fields on the search page in order for a query to be
processed.
</p>
</body>
</html>
RESULTS
}

######################################################################
######################################################################

=pod 

=item &output_date_error()

Output a full html page with an error message.

=cut

######################################################################
######################################################################
sub output_date_error {
    my ($r,$message)=@_;
    # make query information persistent to allow for subsequent revision
    my $persistent=&make_persistent();

    $r->print(<<RESULTS);
<html>
<head>
<title>The LearningOnline Network with CAPA</title>
</head>
<body bgcolor="#ffffff">
<img align='right' src='/adm/lonIcons/lonlogos.gif' />
<h1>Search Catalog</h1>
<form method="post" action="/adm/searchcat">
$persistent
<input type='button' value='Revise search request'
onClick='this.form.submit();' />
$closebutton
<hr />
<h3>Helpful Message</h3>
<p>
$message
</p>
</body>
</html>
RESULTS
}

######################################################################
######################################################################

=pod 

=item &start_fresh_session()

Cleans the global %hash by removing all fields which begin with
'pre_' or 'store'.

=cut

######################################################################
######################################################################
sub start_fresh_session {
    delete $hash{'mode_catalog'};
    foreach (keys %hash) {
        if ($_ =~ /^pre_/) {
            delete $hash{$_};
        }
        if ($_ =~ /^store/) {
	    delete $hash{$_};
	}
    }
}

######################################################################
######################################################################

=pod 

=item &popwin_js() send javascript to popwin

=cut

######################################################################
######################################################################
sub popwin_js {
    # Print javascript out to popwin, but make sure we dont generate
    # any javascript errors in doing so.
    my ($r,$text) = @_;
    $r->print(<<"END");
<script type="text/javascript">
    if (! popwin.closed) {
	$text
    }
</script>
END
    $r->rflush();
}

######################################################################
######################################################################

=pod 

=item &popwin_imgupdate()

Send a given image (and its location) out to the browser.  Takes as 
input $r, loncapa server id, and an icon URL.

=cut

######################################################################
######################################################################
sub popwin_imgupdate {
    my ($r,$server,$icon) = @_;
    &popwin_js($r,'popwin.document.img_'.$hostdomains{$server}.'_'.$server.'.'.
	       'src="/adm/lonIcons/'.$icon.'";');
}    

1;

__END__

=pod

=back 

=over 4

=head1 HANDLER SUBROUTINE

This routine is called by Apache and mod_perl.

=over 4

=item *

configure dynamic components of interface

=item *

determine current user

=item *

see if a search invocation should be done

=item *

else, begin building search interface to output

=item *

compute date selection boxes

=item *

compute customized metadata field

=item *

print screen

=back

=head1 OTHER SUBROUTINES

=over 4

=item *

get_unprocessed_cgi() : reads in critical name/value pairs that may have not
been processed and passed into %ENV by the web server

=item *

make_persistent() : makes a set of hidden HTML fields to make
SQL search interface information to be persistent

=back

WEB INTERFACE COMPONENT FUNCTIONS

=over 4

=item *

simpletextfield(name,value) : returns HTML formatted string for simple text
field

=item *

simplecheckbox(name,value) : returns HTML formatted string for simple
checkbox

=item *

searchphrasefield(title,name,value) : returns HTML formatted string for
a search expression phrase field

=item *

dateboxes(name, defaultmonth, defaultday, defaultyear) : returns HTML
formatted string for a calendar date

=item *

selectbox(title,name,value,%HASH=options) : returns HTML formatted string for
a selection box field

=back

SEARCH FUNCTIONS

=over 4

=item *

advancedsearch(server reference, environment reference) : perform a complex
multi-field logical query

=item *

basicsearch(server reference, environment reference) : perform a simple
single-field logical query

=item *

build_SQL_query(field name, logic) : builds a SQL query string from a
logical expression with AND/OR keywords

=item *

build_custommetadata_query(field_name, logic_statement) : builds a perl
regular expression from a logical expression with AND/OR keywords

=item *

recursive_SQL_query_build(field name, reverse notation expression) : 
builds a SQL query string from a reverse notation expression
logical expression with AND/OR keywords

=item *

build_date_queries(cmonth1, cday1, cyear1, cmonth2, cday2, cyear2,
lmonth1, lday1, lyear1, lmonth2, lday2, lyear2) :
Builds a SQL logic query to check time/date entries.

=back

OUTPUTTING RESULTS FUNCTION

=over 4

=item *

output_results(output mode, server reference, environment reference,
reply list reference) : outputs results from search

=back

DIFFERENT WAYS TO VIEW METADATA RECORDS

=over 4

=item *

detailed_citation_view(ORDERED METADATA LIST FOR A RESULT OBJECT INSTANCE) :
see metadata viewing notes below 

=item *

summary_view(ORDERED METADATA LIST FOR A RESULT OBJECT INSTANCE) :
see metadata viewing notes below 

=item *

fielded_format_view(ORDERED METADATA LIST FOR A RESULT OBJECT INSTANCE) :
see metadata viewing notes below 

=item *

xml_sgml_view(ORDERED METADATA LIST FOR A RESULT OBJECT INSTANCE) :
see metadata viewing notes below 

=back

  _____________________________________________________________________
 | * Metadata viewing notes                                            |
 | Output is a HTML-ified string.                                      |
 | Input arguments are title, author, subject, url, keywords, version, |
 | notes, short abstract, mime, language, creation date,               |
 | last revision date, owner, copyright, hostname, httphost, and       |
 | extra custom metadata to show.                                      |
  ---------------------------------------------------------------------

TEST CONDITIONAL FUNCTIONS

=over 4

=item *

filled(field) : determines whether a given field has been filled

=back

ERROR FUNCTIONS

=over 4

=item *

output_blank_field_error(server reference) : outputs a message saying that
more fields need to be filled in

=item *

output_date_error(server reference, error message) : 


=back

=cut