Diff for /loncom/interface/loncommon.pm between versions 1.25 and 1.169

version 1.25, 2002/02/26 20:59:28 version 1.169, 2004/01/02 19:23:47
Line 25 Line 25
 #  #
 # http://www.lon-capa.org/  # http://www.lon-capa.org/
 #  #
 # YEAR=2001  
 # 2/13-12/7 Guy Albertelli  
 # 12/11,12/12,12/17 Scott Harrison  
 # 12/21 Gerd Kortemeyer  
 # 12/21 Scott Harrison  
 # 12/25,12/28 Gerd Kortemeyer  
 # YEAR=2002  
 # 1/4 Gerd Kortemeyer  
   
 # Makes a table out of the previous attempts  # Makes a table out of the previous attempts
 # Inputs result_from_symbread, user, domain, course_id  # Inputs result_from_symbread, user, domain, course_id
 # Reads in non-network-related .tab files  # Reads in non-network-related .tab files
   
   # POD header:
   
   =pod
   
   =head1 NAME
   
   Apache::loncommon - pile of common routines
   
   =head1 SYNOPSIS
   
   Common routines for manipulating connections, student answers,
       domains, common Javascript fragments, etc.
   
   =head1 OVERVIEW
   
   A collection of commonly used subroutines that don't have a natural
   home anywhere else. This collection helps remove
   redundancy from other modules and increase efficiency of memory usage.
   
   =cut 
   
   # End of POD header
 package Apache::loncommon;  package Apache::loncommon;
   
 use strict;  use strict;
 use Apache::lonnet();  use Apache::lonnet();
 use POSIX qw(strftime);  use GDBM_File;
 use Apache::Constants qw(:common);  use POSIX qw(strftime mktime);
   use Apache::Constants qw(:common :http :methods);
 use Apache::lonmsg();  use Apache::lonmsg();
   use Apache::lonmenu();
   use Apache::lonlocal;
   use HTML::Entities;
   
 my $readit;  my $readit;
   
   ##
   ## Global Variables
   ##
   
 # ----------------------------------------------- Filetypes/Languages/Copyright  # ----------------------------------------------- Filetypes/Languages/Copyright
 my %language;  my %language;
   my %supported_language;
 my %cprtag;  my %cprtag;
 my %fe; my %fd;  my %fe; my %fd;
 my %fc;  my %category_extensions;
   
 # -------------------------------------------------------------- Thesaurus data  # ---------------------------------------------- Designs
 my @therelated;  
 my @theword;  
 my @thecount;  
 my %theindex;  
 my $thetotalcount;  
 my $thefuzzy=2;  
 my $thethreshold=0.1/$thefuzzy;  
 my $theavecount;  
   
 # ----------------------------------------------------------------------- BEGIN  my %designhash;
 BEGIN {  
   
   # ---------------------------------------------- Thesaurus variables
   #
   # %Keywords:
   #      A hash used by &keyword to determine if a word is considered a keyword.
   # $thesaurus_db_file 
   #      Scalar containing the full path to the thesaurus database.
   
   my %Keywords;
   my $thesaurus_db_file;
   
   #
   # Initialize values from language.tab, copyright.tab, filetypes.tab,
   # thesaurus.tab, and filecategories.tab.
   #
   BEGIN {
       # Variable initialization
       $thesaurus_db_file = $Apache::lonnet::perlvar{'lonTabDir'}."/thesaurus.db";
       #
     unless ($readit) {      unless ($readit) {
 # ------------------------------------------------------------------- languages  # ------------------------------------------------------------------- languages
     {      {
  my $fh=Apache::File->new($Apache::lonnet::perlvar{'lonTabDir'}.          my $langtabfile = $Apache::lonnet::perlvar{'lonTabDir'}.
  '/language.tab');                                     '/language.tab';
  if ($fh) {          if ( open(my $fh,"<$langtabfile") ) {
     while (<$fh>) {              while (<$fh>) {
  next if /^\#/;                  next if /^\#/;
  chomp;                  chomp;
  my ($key,$val)=(split(/\s+/,$_,2));                  my ($key,$two,$country,$three,$enc,$val,$sup)=(split(/\t/,$_));
  $language{$key}=$val;                  $language{$key}=$val.' - '.$enc;
     }                  if ($sup) {
  }                      $supported_language{$key}=$sup;
                   }
               }
               close($fh);
           }
     }      }
 # ------------------------------------------------------------------ copyrights  # ------------------------------------------------------------------ copyrights
     {      {
  my $fh=Apache::File->new($Apache::lonnet::perlvar{'lonIncludes'}.          my $copyrightfile = $Apache::lonnet::perlvar{'lonIncludes'}.
   '/copyright.tab');                                    '/copyright.tab';
  if ($fh) {          if ( open (my $fh,"<$copyrightfile") ) {
     while (<$fh>) {              while (<$fh>) {
  next if /^\#/;                  next if /^\#/;
  chomp;                  chomp;
  my ($key,$val)=(split(/\s+/,$_,2));                  my ($key,$val)=(split(/\s+/,$_,2));
  $cprtag{$key}=$val;                  $cprtag{$key}=$val;
     }              }
  }              close($fh);
           }
     }      }
 # ------------------------------------------------------------- file categories  
   # -------------------------------------------------------------- domain designs
   
       my $filename;
       my $designdir=$Apache::lonnet::perlvar{'lonTabDir'}.'/lonDomColors';
       opendir(DIR,$designdir);
       while ($filename=readdir(DIR)) {
    my ($domain)=($filename=~/^(\w+)\./);
     {      {
  my $fh=Apache::File->new($Apache::lonnet::perlvar{'lonTabDir'}.          my $designfile = $designdir.'/'.$filename;
   '/filecategories.tab');          if ( open (my $fh,"<$designfile") ) {
  if ($fh) {              while (<$fh>) {
     while (<$fh>) {                  next if /^\#/;
  next if /^\#/;                  chomp;
  chomp;                  my ($key,$val)=(split(/\=/,$_));
  my ($key,$val)=(split(/\s+/,$_,2));                  if ($val) { $designhash{$domain.'.'.$key}=$val; }
  push @{$fc{$key}},$val;              }
     }              close($fh);
  }          }
     }      }
 # ------------------------------------------------------------------ file types  
       }
       closedir(DIR);
   
   
   # ------------------------------------------------------------- file categories
     {      {
  my $fh=Apache::File->new($Apache::lonnet::perlvar{'lonTabDir'}.          my $categoryfile = $Apache::lonnet::perlvar{'lonTabDir'}.
        '/filetypes.tab');                                    '/filecategories.tab';
  if ($fh) {          if ( open (my $fh,"<$categoryfile") ) {
             while (<$fh>) {              while (<$fh>) {
  next if (/^\#/);                  next if /^\#/;
  chomp;                  chomp;
  my ($ending,$emb,$descr)=split(/\s+/,$_,3);                  my ($extension,$category)=(split(/\s+/,$_,2));
  if ($descr ne '') {                   push @{$category_extensions{lc($category)}},$extension;
     $fe{$ending}=lc($emb);              }
     $fd{$ending}=$descr;              close($fh);
  }          }
     }  
  }  
     }      }
 # -------------------------------------------------------------- Thesaurus data  # ------------------------------------------------------------------ file types
     {      {
  my $fh=Apache::File->new($Apache::lonnet::perlvar{'lonTabDir'}.          my $typesfile = $Apache::lonnet::perlvar{'lonTabDir'}.
        '/thesaurus.dat');                 '/filetypes.tab';
  if ($fh) {          if ( open (my $fh,"<$typesfile") ) {
             while (<$fh>) {              while (<$fh>) {
                my ($tword,$tindex,$tcount,$trelated)=split(/\@/,$_);                  next if (/^\#/);
                $theindex{$tword}=$tindex;                  chomp;
                $theword[$tindex]=$tword;                  my ($ending,$emb,$descr)=split(/\s+/,$_,3);
                $thecount[$tindex]=$tcount;                  if ($descr ne '') {
                $thetotalcount+=$tcount;                      $fe{$ending}=lc($emb);
                $therelated[$tindex]=$trelated;                      $fd{$ending}=$descr;
    }                  }
               }
               close($fh);
         }          }
         $theavecount=$thetotalcount/$#thecount;  
     }      }
     &Apache::lonnet::logthis(      &Apache::lonnet::logthis(
               "<font color=yellow>INFO: Read file types and thesaurus</font>");                "<font color=yellow>INFO: Read file types</font>");
     $readit=1;      $readit=1;
       }  # end of unless($readit) 
       
 }  }
   
   ###############################################################
   ##           HTML and Javascript Helper Functions            ##
   ###############################################################
   
   =pod 
   
   =head1 HTML and Javascript Functions
   
   =over 4
   
   =item * browser_and_searcher_javascript ()
   
   X<browsing, javascript>X<searching, javascript>Returns a string
   containing javascript with two functions, C<openbrowser> and
   C<opensearcher>. Returned string does not contain E<lt>scriptE<gt>
   tags.
   
   =item * openbrowser(formname,elementname,only,omit) [javascript]
   
   inputs: formname, elementname, only, omit
   
   formname and elementname indicate the name of the html form and name of
   the element that the results of the browsing selection are to be placed in. 
   
   Specifying 'only' will restrict the browser to displaying only files
   with the given extension.  Can be a comma seperated list.
   
   Specifying 'omit' will restrict the browser to NOT displaying files
   with the given extension.  Can be a comma seperated list.
   
   =item * opensearcher(formname, elementname) [javascript]
   
   Inputs: formname, elementname
   
   formname and elementname specify the name of the html form and the name
   of the element the selection from the search results will be placed in.
   
   =cut
   
   sub browser_and_searcher_javascript {
       return <<END;
       var editbrowser = null;
       function openbrowser(formname,elementname,only,omit,titleelement) {
           var url = '/res/?';
           if (editbrowser == null) {
               url += 'launch=1&';
           }
           url += 'catalogmode=interactive&';
           url += 'mode=edit&';
           url += 'form=' + formname + '&';
           if (only != null) {
               url += 'only=' + only + '&';
           } 
           if (omit != null) {
               url += 'omit=' + omit + '&';
           }
           if (titleelement != null) {
               url += 'titleelement=' + titleelement + '&';
           }
           url += 'element=' + elementname + '';
           var title = 'Browser';
           var options = 'scrollbars=1,resizable=1,menubar=0';
           options += ',width=700,height=600';
           editbrowser = open(url,title,options,'1');
           editbrowser.focus();
       }
       var editsearcher;
       function opensearcher(formname,elementname,titleelement) {
           var url = '/adm/searchcat?';
           if (editsearcher == null) {
               url += 'launch=1&';
           }
           url += 'catalogmode=interactive&';
           url += 'mode=edit&';
           url += 'form=' + formname + '&';
           if (titleelement != null) {
               url += 'titleelement=' + titleelement + '&';
           }
           url += 'element=' + elementname + '';
           var title = 'Search';
           var options = 'scrollbars=1,resizable=1,menubar=0';
           options += ',width=700,height=600';
           editsearcher = open(url,title,options,'1');
           editsearcher.focus();
       }
   END
 }  }
 # ============================================================= END BEGIN BLOCK  
   
   sub studentbrowser_javascript {
      unless (
               (($ENV{'request.course.id'}) && 
                (&Apache::lonnet::allowed('srm',$ENV{'request.course.id'})))
            || ($ENV{'request.role'}=~/^(au|dc|su)/)
             ) { return ''; }  
      return (<<'ENDSTDBRW');
   <script type="text/javascript" language="Javascript" >
       var stdeditbrowser;
       function openstdbrowser(formname,uname,udom,roleflag) {
           var url = '/adm/pickstudent?';
           var filter;
           eval('filter=document.'+formname+'.'+uname+'.value;');
           if (filter != null) {
              if (filter != '') {
                  url += 'filter='+filter+'&';
      }
           }
           url += 'form=' + formname + '&unameelement='+uname+
                                       '&udomelement='+udom;
    if (roleflag) { url+="&roles=1"; }
           var title = 'Student_Browser';
           var options = 'scrollbars=1,resizable=1,menubar=0';
           options += ',width=700,height=600';
           stdeditbrowser = open(url,title,options,'1');
           stdeditbrowser.focus();
       }
   </script>
   ENDSTDBRW
   }
   
 # ---------------------------------------------------------- Is this a keyword?  sub selectstudent_link {
      my ($form,$unameele,$udomele)=@_;
      if ($ENV{'request.course.id'}) {  
          unless (&Apache::lonnet::allowed('srm',$ENV{'request.course.id'})) {
      return '';
          }
          return "<a href='".'javascript:openstdbrowser("'.$form.'","'.$unameele.
           '","'.$udomele.'");'."'>".&mt('Select User')."</a>";
      }
      if ($ENV{'request.role'}=~/^(au|dc|su)/) {
          return "<a href='".'javascript:openstdbrowser("'.$form.'","'.$unameele.
           '","'.$udomele.'",1);'."'>".&mt('Select User')."</a>";
      }
      return '';
   }
   
   sub coursebrowser_javascript {
       my ($domainfilter)=@_;
      return (<<ENDSTDBRW);
   <script type="text/javascript" language="Javascript" >
       var stdeditbrowser;
       function opencrsbrowser(formname,uname,udom) {
           var url = '/adm/pickcourse?';
           var filter;
           if (filter != null) {
              if (filter != '') {
                  url += 'filter='+filter+'&';
      }
           }
           var domainfilter='$domainfilter';
           if (domainfilter != null) {
              if (domainfilter != '') {
                  url += 'domainfilter='+domainfilter+'&';
      }
           }
           url += 'form=' + formname + '&cnumelement='+uname+
                                       '&cdomelement='+udom;
           var title = 'Course_Browser';
           var options = 'scrollbars=1,resizable=1,menubar=0';
           options += ',width=700,height=600';
           stdeditbrowser = open(url,title,options,'1');
           stdeditbrowser.focus();
       }
   </script>
   ENDSTDBRW
   }
   
 sub keyword {  sub selectcourse_link {
     my $newword=shift;     my ($form,$unameele,$udomele)=@_;
     $newword=~s/\W//g;      return "<a href='".'javascript:opencrsbrowser("'.$form.'","'.$unameele.
     $newword=~tr/A-Z/a-z/;          '","'.$udomele.'");'."'>".&mt('Select Course')."</a>";
     my $tindex=$theindex{$newword};  }
     if ($tindex) {  
         if ($thecount[$tindex]>$theavecount) {  =pod
            return 1;  
         }  =item * linked_select_forms(...)
     }  
     return 0;  linked_select_forms returns a string containing a <script></script> block
 }  and html for two <select> menus.  The select menus will be linked in that
 # -------------------------------------------------------- Return related words  changing the value of the first menu will result in new values being placed
   in the second menu.  The values in the select menu will appear in alphabetical
 sub related {  order.
     my $newword=shift;  
     $newword=~s/\W//g;  linked_select_forms takes the following ordered inputs:
     $newword=~tr/A-Z/a-z/;  
     my $tindex=$theindex{$newword};  =over 4
     if ($tindex) {  
         my %found=();  =item * $formname, the name of the <form> tag
         foreach (split(/\,/,$therelated[$tindex])) {  
 # - Related word found  =item * $middletext, the text which appears between the <select> tags
             my ($ridx,$rcount)=split(/\:/,$_);  
 # - Direct relation index  =item * $firstdefault, the default value for the first menu
             my $directrel=$rcount/$thecount[$tindex];  
             if ($directrel>$thethreshold) {  =item * $firstselectname, the name of the first <select> tag
                foreach (split(/\,/,$therelated[$ridx])) {  
                   my ($rridx,$rrcount)=split(/\:/,$_);  =item * $secondselectname, the name of the second <select> tag
                   if ($rridx==$tindex) {  
 # - Determine reverse relation index  =item * $hashref, a reference to a hash containing the data for the menus.
                      my $revrel=$rrcount/$thecount[$ridx];  
 # - Calculate full index  =back 
                      $found{$ridx}=$directrel*$revrel;  
                      if ($found{$ridx}>$thethreshold) {  Below is an example of such a hash.  Only the 'text', 'default', and 
                         foreach (split(/\,/,$therelated[$ridx])) {  'select2' keys must appear as stated.  keys(%menu) are the possible 
                             my ($rrridx,$rrrcount)=split(/\:/,$_);  values for the first select menu.  The text that coincides with the 
                             unless ($found{$rrridx}) {  first menu value is given in $menu{$choice1}->{'text'}.  The values 
                                my $revrevrel=$rrrcount/$thecount[$ridx];  and text for the second menu are given in the hash pointed to by 
                                if (  $menu{$choice1}->{'select2'}.  
                           $directrel*$revrel*$revrevrel>$thethreshold  
                                ) {   my %menu = ( A1 => { text =>"Choice A1" ,
                                   $found{$rrridx}=                         default => "B3",
                                        $directrel*$revrel*$revrevrel;                         select2 => { 
                                }                             B1 => "Choice B1",
                             }                             B2 => "Choice B2",
                         }                             B3 => "Choice B3",
                      }                             B4 => "Choice B4"
                   }                             }
                }                     },
                  A2 => { text =>"Choice A2" ,
                          default => "C2",
                          select2 => { 
                              C1 => "Choice C1",
                              C2 => "Choice C2",
                              C3 => "Choice C3"
                              }
                      },
                  A3 => { text =>"Choice A3" ,
                          default => "D6",
                          select2 => { 
                              D1 => "Choice D1",
                              D2 => "Choice D2",
                              D3 => "Choice D3",
                              D4 => "Choice D4",
                              D5 => "Choice D5",
                              D6 => "Choice D6",
                              D7 => "Choice D7"
                              }
                      }
                  );
   
   =cut
   
   sub linked_select_forms {
       my ($formname,
           $middletext,
           $firstdefault,
           $firstselectname,
           $secondselectname, 
           $hashref
           ) = @_;
       my $second = "document.$formname.$secondselectname";
       my $first = "document.$formname.$firstselectname";
       # output the javascript to do the changing
       my $result = '';
       $result.="<script>\n";
       $result.="var select2data = new Object();\n";
       $" = '","';
       my $debug = '';
       foreach my $s1 (sort(keys(%$hashref))) {
           $result.="select2data.d_$s1 = new Object();\n";        
           $result.="select2data.d_$s1.def = new String('".
               $hashref->{$s1}->{'default'}."');\n";
           $result.="select2data.d_$s1.values = new Array(";        
           my @s2values = sort(keys( %{ $hashref->{$s1}->{'select2'} } ));
           $result.="\"@s2values\");\n";
           $result.="select2data.d_$s1.texts = new Array(";        
           my @s2texts;
           foreach my $value (@s2values) {
               push @s2texts, $hashref->{$s1}->{'select2'}->{$value};
           }
           $result.="\"@s2texts\");\n";
       }
       $"=' ';
       $result.= <<"END";
   
   function select1_changed() {
       // Determine new choice
       var newvalue = "d_" + $first.value;
       // update select2
       var values     = select2data[newvalue].values;
       var texts      = select2data[newvalue].texts;
       var select2def = select2data[newvalue].def;
       var i;
       // out with the old
       for (i = 0; i < $second.options.length; i++) {
           $second.options[i] = null;
       }
       // in with the nuclear
       for (i=0;i<values.length; i++) {
           $second.options[i] = new Option(values[i]);
           $second.options[i].value = values[i];
           $second.options[i].text = texts[i];
           if (values[i] == select2def) {
               $second.options[i].selected = true;
           }
       }
   }
   </script>
   END
       # output the initial values for the selection lists
       $result .= "<select size=\"1\" name=\"$firstselectname\" onchange=\"select1_changed()\">\n";
       foreach my $value (sort(keys(%$hashref))) {
           $result.="    <option value=\"$value\" ";
           $result.=" selected=\"true\" " if ($value eq $firstdefault);
           $result.=">".&mt($hashref->{$value}->{'text'})."</option>\n";
       }
       $result .= "</select>\n";
       my %select2 = %{$hashref->{$firstdefault}->{'select2'}};
       $result .= $middletext;
       $result .= "<select size=\"1\" name=\"$secondselectname\">\n";
       my $seconddefault = $hashref->{$firstdefault}->{'default'};
       foreach my $value (sort(keys(%select2))) {
           $result.="    <option value=\"$value\" ";        
           $result.=" selected=\"true\" " if ($value eq $seconddefault);
           $result.=">".&mt($select2{$value})."</option>\n";
       }
       $result .= "</select>\n";
       #    return $debug;
       return $result;
   }   #  end of sub linked_select_forms {
   
   =pod
   
   =item * help_open_topic($topic, $text, $stayOnPage, $width, $height)
   
   Returns a string corresponding to an HTML link to the given help
   $topic, where $topic corresponds to the name of a .tex file in
   /home/httpd/html/adm/help/tex, with underscores replaced by
   spaces. 
   
   $text will optionally be linked to the same topic, allowing you to
   link text in addition to the graphic. If you do not want to link
   text, but wish to specify one of the later parameters, pass an
   empty string. 
   
   $stayOnPage is a value that will be interpreted as a boolean. If true,
   the link will not open a new window. If false, the link will open
   a new window using Javascript. (Default is false.) 
   
   $width and $height are optional numerical parameters that will
   override the width and height of the popped up window, which may
   be useful for certain help topics with big pictures included. 
   
   =cut
   
   sub help_open_topic {
       my ($topic, $text, $stayOnPage, $width, $height) = @_;
       $text = "" if (not defined $text);
       $stayOnPage = 0 if (not defined $stayOnPage);
       if ($ENV{'browser.interface'} eq 'textual' ||
    $ENV{'environment.remote'} eq 'off' ) {
    $stayOnPage=1;
       }
       $width = 350 if (not defined $width);
       $height = 400 if (not defined $height);
       my $filename = $topic;
       $filename =~ s/ /_/g;
   
       my $template = "";
       my $link;
   
       $topic=~s/\W/\_/g;
   
       if (!$stayOnPage)
       {
    $link = "javascript:void(open('/adm/help/${filename}.hlp', 'Help_for_$topic', 'menubar=0,toolbar=1,scrollbars=1,width=$width,height=$height,resizable=yes'))";
       }
       else
       {
    $link = "/adm/help/${filename}.hlp";
       }
   
       # Add the text
       if ($text ne "")
       {
    $template .= 
     "<table bgcolor='#3333AA' cellspacing='1' cellpadding='1' border='0'><tr>".
     "<td bgcolor='#5555FF'><a href=\"$link\"><font color='#FFFFFF' size='2'>$text</font></a>";
       }
   
       # Add the graphic
       $template .= <<"ENDTEMPLATE";
    <a href="$link"><image src="/adm/help/gif/smallHelp.gif" border="0" alt="(Help: $topic)" /></a>
   ENDTEMPLATE
       if ($text ne '') { $template.='</td></tr></table>' };
       return $template;
   
   }
   
   # This is a quicky function for Latex cheatsheet editing, since it 
   # appears in at least four places
   sub helpLatexCheatsheet {
       my $other = shift;
       my $addOther = '';
       if ($other) {
    $addOther = Apache::loncommon::help_open_topic($other, shift,
          undef, undef, 600) .
      '</td><td>';
       }
       return '<table><tr><td>'.
    $addOther .
    &Apache::loncommon::help_open_topic("Greek_Symbols",'Greek Symbols',
       undef,undef,600)
    .'</td><td>'.
    &Apache::loncommon::help_open_topic("Other_Symbols",'Other Symbols',
       undef,undef,600)
    .'</td></tr></table>';
   }
   
   =pod
   
   =item * csv_translate($text) 
   
   Translate $text to allow it to be output as a 'comma seperated values' 
   format.
   
   =cut
   
   sub csv_translate {
       my $text = shift;
       $text =~ s/\"/\"\"/g;
       $text =~ s/\n//g;
       return $text;
   }
   
   =pod
   
   =item * change_content_javascript():
   
   This and the next function allow you to create small sections of an
   otherwise static HTML page that you can update on the fly with
   Javascript, even in Netscape 4.
   
   The Javascript fragment returned by this function (no E<lt>scriptE<gt> tag)
   must be written to the HTML page once. It will prove the Javascript
   function "change(name, content)". Calling the change function with the
   name of the section 
   you want to update, matching the name passed to C<changable_area>, and
   the new content you want to put in there, will put the content into
   that area.
   
   B<Note>: Netscape 4 only reserves enough space for the changable area
   to contain room for the original contents. You need to "make space"
   for whatever changes you wish to make, and be B<sure> to check your
   code in Netscape 4. This feature in Netscape 4 is B<not> powerful;
   it's adequate for updating a one-line status display, but little more.
   This script will set the space to 100% width, so you only need to
   worry about height in Netscape 4.
   
   Modern browsers are much less limiting, and if you can commit to the
   user not using Netscape 4, this feature may be used freely with
   pretty much any HTML.
   
   =cut
   
   sub change_content_javascript {
       # If we're on Netscape 4, we need to use Layer-based code
       if ($ENV{'browser.type'} eq 'netscape' &&
    $ENV{'browser.version'} =~ /^4\./) {
    return (<<NETSCAPE4);
    function change(name, content) {
       doc = document.layers[name+"___escape"].layers[0].document;
       doc.open();
       doc.write(content);
       doc.close();
    }
   NETSCAPE4
       } else {
    # Otherwise, we need to use semi-standards-compliant code
    # (technically, "innerHTML" isn't standard but the equivalent
    # is really scary, and every useful browser supports it
    return (<<DOMBASED);
    function change(name, content) {
       element = document.getElementById(name);
       element.innerHTML = content;
    }
   DOMBASED
       }
   }
   
   =pod
   
   =item * changable_area($name, $origContent):
   
   This provides a "changable area" that can be modified on the fly via
   the Javascript code provided in C<change_content_javascript>. $name is
   the name you will use to reference the area later; do not repeat the
   same name on a given HTML page more then once. $origContent is what
   the area will originally contain, which can be left blank.
   
   =cut
   
   sub changable_area {
       my ($name, $origContent) = @_;
   
       if ($ENV{'browser.type'} eq 'netscape' &&
    $ENV{'browser.version'} =~ /^4\./) {
    # If this is netscape 4, we need to use the Layer tag
    return "<ilayer width='100%' id='${name}___escape' overflow='none'><layer width='100%' id='$name' overflow='none'>$origContent</layer></ilayer>";
       } else {
    return "<span id='$name'>$origContent</span>";
       }
   }
   
   =pod
   
   =back
   
   =cut
   
   ###############################################################
   ##        Home server <option> list generating code          ##
   ###############################################################
   
   =pod
   
   =head1 Home Server option list generating code
   
   =over 4
   
   =item * get_domains()
   
   Returns an array containing each of the domains listed in the hosts.tab
   file.
   
   =cut
   
   #-------------------------------------------
   sub get_domains {
       # The code below was stolen from "The Perl Cookbook", p 102, 1st ed.
       my @domains;
       my %seen;
       foreach (sort values(%Apache::lonnet::hostdom)) {
    push (@domains,$_) unless $seen{$_}++;
       }
       return @domains;
   }
   
   # ------------------------------------------
   
   sub domain_select {
       my ($name,$value,$multiple)=@_;
       my %domains=map { 
    $_ => $_.' '.$Apache::lonnet::domaindescription{$_} 
       } &get_domains;
       if ($multiple) {
    $domains{''}=&mt('Any domain');
    return &multiple_select_form($name,$value,%domains);
       } else {
    return &select_form($name,$value,%domains);
       }
   }
   
   sub multiple_select_form {
       my ($name,$value,%hash)=@_;
       my %selected = map { $_ => 1 } ref($value)?@{$value}:($value);
       my $output='';
       my $size =(scalar keys %hash<4?scalar keys %hash:4);
       $output.="\n<select name='$name' size='$size' multiple='1'>";
       foreach (sort keys %hash) {
           $output.="<option name='$_'".
               ($selected{$_}?' selected="1"' :'').">$hash{$_}</option>\n";
       }
       $output.="</select>\n";
       return $output;
   }
   
   #-------------------------------------------
   
   =pod
   
   =item * select_form($defdom,$name,%hash)
   
   Returns a string containing a <select name='$name' size='1'> form to 
   allow a user to select options from a hash option_name => displayed text.  
   See lonrights.pm for an example invocation and use.
   
   =cut
   
   #-------------------------------------------
   sub select_form {
       my ($def,$name,%hash) = @_;
       my $selectform = "<select name=\"$name\" size=\"1\">\n";
       my @keys;
       if (exists($hash{'select_form_order'})) {
    @keys=@{$hash{'select_form_order'}};
       } else {
    @keys=sort(keys(%hash));
       }
       foreach (@keys) {
           $selectform.="<option value=\"$_\" ".
               ($_ eq $def ? 'selected' : '').
                   ">".&mt($hash{$_})."</option>\n";
       }
       $selectform.="</select>";
       return $selectform;
   }
   
   sub gradeleveldescription {
       my $gradelevel=shift;
       my %gradelevels=(0 => 'Not specified',
        1 => 'Grade 1',
        2 => 'Grade 2',
        3 => 'Grade 3',
        4 => 'Grade 4',
        5 => 'Grade 5',
        6 => 'Grade 6',
        7 => 'Grade 7',
        8 => 'Grade 8',
        9 => 'Grade 9',
        10 => 'Grade 10',
        11 => 'Grade 11',
        12 => 'Grade 12',
        13 => 'Grade 13',
        14 => '100 Level',
        15 => '200 Level',
        16 => '300 Level',
        17 => '400 Level',
        18 => 'Graduate Level');
       return &mt($gradelevels{$gradelevel});
   }
   
   sub select_level_form {
       my ($deflevel,$name)=@_;
       unless ($deflevel) { $deflevel=0; }
       my $selectform = "<select name=\"$name\" size=\"1\">\n";
       for (my $i=0; $i<=18; $i++) {
           $selectform.="<option value=\"$i\" ".
               ($i==$deflevel ? 'selected' : '').
                   ">".&gradeleveldescription($i)."</option>\n";
       }
       $selectform.="</select>";
       return $selectform;
   }
   
   #-------------------------------------------
   
   =pod
   
   =item * select_dom_form($defdom,$name,$includeempty)
   
   Returns a string containing a <select name='$name' size='1'> form to 
   allow a user to select the domain to preform an operation in.  
   See loncreateuser.pm for an example invocation and use.
   
   If the $includeempty flag is set, it also includes an empty choice ("no domain
   selected");
   
   =cut
   
   #-------------------------------------------
   sub select_dom_form {
       my ($defdom,$name,$includeempty) = @_;
       my @domains = get_domains();
       if ($includeempty) { @domains=('',@domains); }
       my $selectdomain = "<select name=\"$name\" size=\"1\">\n";
       foreach (@domains) {
           $selectdomain.="<option value=\"$_\" ".
               ($_ eq $defdom ? 'selected' : '').
                   ">$_</option>\n";
       }
       $selectdomain.="</select>";
       return $selectdomain;
   }
   
   #-------------------------------------------
   
   =pod
   
   =item * get_library_servers($domain)
   
   Returns a hash which contains keys like '103l3' and values like 
   'kirk.lite.msu.edu'.  All of the keys will be for machines in the
   given $domain.
   
   =cut
   
   #-------------------------------------------
   sub get_library_servers {
       my $domain = shift;
       my %library_servers;
       foreach (keys(%Apache::lonnet::libserv)) {
           if ($Apache::lonnet::hostdom{$_} eq $domain) {
               $library_servers{$_} = $Apache::lonnet::hostname{$_};
           }
       }
       return %library_servers;
   }
   
   #-------------------------------------------
   
   =pod
   
   =item * home_server_option_list($domain)
   
   returns a string which contains an <option> list to be used in a 
   <select> form input.  See loncreateuser.pm for an example.
   
   =cut
   
   #-------------------------------------------
   sub home_server_option_list {
       my $domain = shift;
       my %servers = &get_library_servers($domain);
       my $result = '';
       foreach (sort keys(%servers)) {
           $result.=
               '<option value="'.$_.'">'.$_.' '.$servers{$_}."</option>\n";
       }
       return $result;
   }
   
   =pod
   
   =back
   
   =cut
   
   ###############################################################
   ##                  Decoding User Agent                      ##
   ###############################################################
   
   =pod
   
   =head1 Decoding the User Agent
   
   =over 4
   
   =item * &decode_user_agent()
   
   Inputs: $r
   
   Outputs:
   
   =over 4
   
   =item * $httpbrowser
   
   =item * $clientbrowser
   
   =item * $clientversion
   
   =item * $clientmathml
   
   =item * $clientunicode
   
   =item * $clientos
   
   =back
   
   =back 
   
   =cut
   
   ###############################################################
   ###############################################################
   sub decode_user_agent {
       my @browsertype=split(/\&/,$Apache::lonnet::perlvar{"lonBrowsDet"});
       my %mathcap=split(/\&/,$$Apache::lonnet::perlvar{"lonMathML"});
       my $httpbrowser=$ENV{"HTTP_USER_AGENT"};
       my $clientbrowser='unknown';
       my $clientversion='0';
       my $clientmathml='';
       my $clientunicode='0';
       for (my $i=0;$i<=$#browsertype;$i++) {
           my ($bname,$match,$notmatch,$vreg,$minv,$univ)=split(/\:/,$browsertype[$i]);
    if (($httpbrowser=~/$match/i)  && ($httpbrowser!~/$notmatch/i)) {
       $clientbrowser=$bname;
               $httpbrowser=~/$vreg/i;
       $clientversion=$1;
               $clientmathml=($clientversion>=$minv);
               $clientunicode=($clientversion>=$univ);
    }
       }
       my $clientos='unknown';
       if (($httpbrowser=~/linux/i) ||
           ($httpbrowser=~/unix/i) ||
           ($httpbrowser=~/ux/i) ||
           ($httpbrowser=~/solaris/i)) { $clientos='unix'; }
       if (($httpbrowser=~/vax/i) ||
           ($httpbrowser=~/vms/i)) { $clientos='vms'; }
       if ($httpbrowser=~/next/i) { $clientos='next'; }
       if (($httpbrowser=~/mac/i) ||
           ($httpbrowser=~/powerpc/i)) { $clientos='mac'; }
       if ($httpbrowser=~/win/i) { $clientos='win'; }
       if ($httpbrowser=~/embed/i) { $clientos='pda'; }
       return ($httpbrowser,$clientbrowser,$clientversion,$clientmathml,
               $clientunicode,$clientos,);
   }
   
   ###############################################################
   ##    Authentication changing form generation subroutines    ##
   ###############################################################
   ##
   ## All of the authform_xxxxxxx subroutines take their inputs in a
   ## hash, and have reasonable default values.
   ##
   ##    formname = the name given in the <form> tag.
   #-------------------------------------------
   
   =pod
   
   =head1 Authentication Routines
   
   =over 4
   
   =item * authform_xxxxxx
   
   The authform_xxxxxx subroutines provide javascript and html forms which 
   handle some of the conveniences required for authentication forms.  
   This is not an optimal method, but it works.  
   
   See loncreateuser.pm for invocation and use examples.
   
   =over 4
   
   =item * authform_header
   
   =item * authform_authorwarning
   
   =item * authform_nochange
   
   =item * authform_kerberos
   
   =item * authform_internal
   
   =item * authform_filesystem
   
   =back
   
   =back 
   
   =cut
   
   #-------------------------------------------
   sub authform_header{  
       my %in = (
           formname => 'cu',
           kerb_def_dom => '',
           @_,
       );
       $in{'formname'} = 'document.' . $in{'formname'};
       my $result='';
   
   #---------------------------------------------- Code for upper case translation
       my $Javascript_toUpperCase;
       unless ($in{kerb_def_dom}) {
           $Javascript_toUpperCase =<<"END";
           switch (choice) {
              case 'krb': currentform.elements[choicearg].value =
                  currentform.elements[choicearg].value.toUpperCase();
                  break;
              default:
           }
   END
       } else {
           $Javascript_toUpperCase = "";
       }
   
       my $radioval = "'nochange'";
       my $argfield = 'null';
       if ( grep/^mode$/,(keys %in) ) {
           if ($in{'mode'} eq 'modifycourse')  {
               if ( grep/^curr_authtype$/,(keys %in) ) {
                   $radioval = "'$in{'curr_authtype'}'";
               }
               if ( grep/^curr_autharg$/,(keys %in) ) {
                   unless ($in{'curr_autharg'} eq '') {
                       $argfield = "'$in{'curr_autharg'}'";
                   }
               }
           }
       }
   
       $result.=<<"END";
   var current = new Object();
   current.radiovalue = $radioval;
   current.argfield = $argfield;
   
   function changed_radio(choice,currentform) {
       var choicearg = choice + 'arg';
       // If a radio button in changed, we need to change the argfield
       if (current.radiovalue != choice) {
           current.radiovalue = choice;
           if (current.argfield != null) {
               currentform.elements[current.argfield].value = '';
           }
           if (choice == 'nochange') {
               current.argfield = null;
           } else {
               current.argfield = choicearg;
               switch(choice) {
                   case 'krb': 
                       currentform.elements[current.argfield].value = 
                           "$in{'kerb_def_dom'}";
                   break;
                 default:
                   break;
               }
           }
       }
       return;
   }
   
   function changed_text(choice,currentform) {
       var choicearg = choice + 'arg';
       if (currentform.elements[choicearg].value !='') {
           $Javascript_toUpperCase
           // clear old field
           if ((current.argfield != choicearg) && (current.argfield != null)) {
               currentform.elements[current.argfield].value = '';
           }
           current.argfield = choicearg;
       }
       set_auth_radio_buttons(choice,currentform);
       return;
   }
   
   function set_auth_radio_buttons(newvalue,currentform) {
       var i=0;
       while (i < currentform.login.length) {
           if (currentform.login[i].value == newvalue) { break; }
           i++;
       }
       if (i == currentform.login.length) {
           return;
       }
       current.radiovalue = newvalue;
       currentform.login[i].checked = true;
       return;
   }
   END
       return $result;
   }
   
   sub authform_authorwarning{
       my $result='';
       $result='<i>'.
           &mt('As a general rule, only authors or co-authors should be '.
               'filesystem authenticated '.
               '(which allows access to the server filesystem).')."</i>\n";
       return $result;
   }
   
   sub authform_nochange{  
       my %in = (
                 formname => 'document.cu',
                 kerb_def_dom => 'MSU.EDU',
                 @_,
             );
       my $result = &mt('[_1] Do not change login data',
                        '<input type="radio" name="login" value="nochange" '.
                        'checked="checked" onclick="'.
               "javascript:changed_radio('nochange',$in{'formname'});".'" />');
       return $result;
   }
   
   sub authform_kerberos{  
       my %in = (
                 formname => 'document.cu',
                 kerb_def_dom => 'MSU.EDU',
                 kerb_def_auth => 'krb4',
                 @_,
                 );
       my ($check4,$check5,$krbarg);
       if ($in{'kerb_def_auth'} eq 'krb5') {
          $check5 = " checked=\"on\"";
       } else {
          $check4 = " checked=\"on\"";
       }
       $krbarg = $in{'kerb_def_dom'};
   
       my $krbcheck = "";
       if ( grep/^curr_authtype$/,(keys %in) ) {
           if ($in{'curr_authtype'} =~ m/^krb/) {
               $krbcheck = " checked=\"on\"";
               if ( grep/^curr_autharg$/,(keys %in) ) {
                   $krbarg = $in{'curr_autharg'};
             }              }
         }          }
     }      }
     return ();  
       my $jscall = "javascript:changed_radio('krb',$in{'formname'});";
       my $result .= &mt
           ('[_1] Kerberos authenticated with domain [_2] '.
            '[_3] Version 4 [_4] Version 5',
            '<input type="radio" name="login" value="krb" '.
                'onclick="'.$jscall.'" onchange="'.$jscall.'"'.$krbcheck.' />',
            '<input type="text" size="10" name="krbarg" '.
                'value="'.$krbarg.'" '.
                'onchange="'.$jscall.'" />',
            '<input type="radio" name="krbver" value="4" '.$check4.' />',
            '<input type="radio" name="krbver" value="5" '.$check5.' />');
       return $result;
   }
   
   sub authform_internal{  
       my %args = (
                   formname => 'document.cu',
                   kerb_def_dom => 'MSU.EDU',
                   @_,
                   );
   
       my $intcheck = "";
       my $intarg = 'value=""';
       if ( grep/^curr_authtype$/,(keys %args) ) {
           if ($args{'curr_authtype'} eq 'int') {
               $intcheck = " checked=\"on\"";
               if ( grep/^curr_autharg$/,(keys %args) ) {
                   $intarg = "value=\"$args{'curr_autharg'}\"";
               }
           }
       }
   
       my $jscall = "javascript:changed_radio('int',$args{'formname'});";
       my $result.=&mt
           ('[_1] Internally authenticated (with initial password [_2])',
            '<input type="radio" name="login" value="int" '.$intcheck.
                ' onchange="'.$jscall.'" onclick="'.$jscall.'" />',
            '<input type="text" size="10" name="intarg" '.$intarg.
                ' onchange="'.$jscall.'" />');
       return $result;
   }
   
   sub authform_local{  
       my %in = (
                 formname => 'document.cu',
                 kerb_def_dom => 'MSU.EDU',
                 @_,
                 );
   
       my $loccheck = "";
       my $locarg = 'value=""';
       if ( grep/^curr_authtype$/,(keys %in) ) {
           if ($in{'curr_authtype'} eq 'loc') {
               $loccheck = " checked=\"on\"";
               if ( grep/^curr_autharg$/,(keys %in) ) {
                   $locarg = "value=\"$in{'curr_autharg'}\"";
               }
           }
       }
   
       my $jscall = "javascript:changed_radio('loc',$in{'formname'});";
       my $result.=&mt('[_1] Local Authentication with argument [_2]',
                       '<input type="radio" name="login" value="loc" '.$loccheck.
                           ' onchange="'.$jscall.'" onclick="'.$jscall.'" />',
                       '<input type="text" size="10" name="locarg" '.$locarg.
                           ' onchange="'.$jscall.'" />');
       return $result;
   }
   
   sub authform_filesystem{  
       my %in = (
                 formname => 'document.cu',
                 kerb_def_dom => 'MSU.EDU',
                 @_,
                 );
       my $jscall = "javascript:changed_radio('fsys',$in{'formname'});";
       my $result.= &mt
           ('[_1] Filesystem Authenticated (with initial password [_2])',
            '<input type="radio" name="login" value="fsys" '.
            'onchange="'.$jscall.'" onclick="'.$jscall.'" />',
            '<input type="text" size="10" name="fsysarg" value="" '.
                     'onchange="'.$jscall.'" />');
       return $result;
   }
   
   ###############################################################
   ##    Get Authentication Defaults for Domain                 ##
   ###############################################################
   
   =pod
   
   =head1 Domains and Authentication
   
   Returns default authentication type and an associated argument as
   listed in file 'domain.tab'.
   
   =over 4
   
   =item * get_auth_defaults
   
   get_auth_defaults($target_domain) returns the default authentication
   type and an associated argument (initial password or a kerberos domain).
   These values are stored in lonTabs/domain.tab
   
   ($def_auth, $def_arg) = &get_auth_defaults($target_domain);
   
   If target_domain is not found in domain.tab, returns nothing ('').
   
   =cut
   
   #-------------------------------------------
   sub get_auth_defaults {
       my $domain=shift;
       return ($Apache::lonnet::domain_auth_def{$domain},$Apache::lonnet::domain_auth_arg_def{$domain});
   }
   ###############################################################
   ##   End Get Authentication Defaults for Domain              ##
   ###############################################################
   
   ###############################################################
   ##    Get Kerberos Defaults for Domain                 ##
   ###############################################################
   ##
   ## Returns default kerberos version and an associated argument
   ## as listed in file domain.tab. If not listed, provides
   ## appropriate default domain and kerberos version.
   ##
   #-------------------------------------------
   
   =pod
   
   =item * get_kerberos_defaults
   
   get_kerberos_defaults($target_domain) returns the default kerberos
   version and domain. If not found in domain.tabs, it defaults to
   version 4 and the domain of the server.
   
   ($def_version, $def_krb_domain) = &get_kerberos_defaults($target_domain);
   
   =cut
   
   #-------------------------------------------
   sub get_kerberos_defaults {
       my $domain=shift;
       my ($krbdef,$krbdefdom) =
           &Apache::loncommon::get_auth_defaults($domain);
       unless ($krbdef =~/^krb/ && $krbdefdom) {
           $ENV{'SERVER_NAME'}=~/(\w+\.\w+)$/;
           my $krbdefdom=$1;
           $krbdefdom=~tr/a-z/A-Z/;
           $krbdef = "krb4";
       }
       return ($krbdef,$krbdefdom);
   }
   
   =pod
   
   =back
   
   =cut
   
   ###############################################################
   ##                Thesaurus Functions                        ##
   ###############################################################
   
   =pod
   
   =head1 Thesaurus Functions
   
   =over 4
   
   =item * initialize_keywords
   
   Initializes the package variable %Keywords if it is empty.  Uses the
   package variable $thesaurus_db_file.
   
   =cut
   
   ###################################################
   
   sub initialize_keywords {
       return 1 if (scalar keys(%Keywords));
       # If we are here, %Keywords is empty, so fill it up
       #   Make sure the file we need exists...
       if (! -e $thesaurus_db_file) {
           &Apache::lonnet::logthis("Attempt to access $thesaurus_db_file".
                                    " failed because it does not exist");
           return 0;
       }
       #   Set up the hash as a database
       my %thesaurus_db;
       if (! tie(%thesaurus_db,'GDBM_File',
                 $thesaurus_db_file,&GDBM_READER(),0640)){
           &Apache::lonnet::logthis("Could not tie \%thesaurus_db to ".
                                    $thesaurus_db_file);
           return 0;
       } 
       #  Get the average number of appearances of a word.
       my $avecount = $thesaurus_db{'average.count'};
       #  Put keywords (those that appear > average) into %Keywords
       while (my ($word,$data)=each (%thesaurus_db)) {
           my ($count,undef) = split /:/,$data;
           $Keywords{$word}++ if ($count > $avecount);
       }
       untie %thesaurus_db;
       # Remove special values from %Keywords.
       foreach ('total.count','average.count') {
           delete($Keywords{$_}) if (exists($Keywords{$_}));
       }
       return 1;
   }
   
   ###################################################
   
   =pod
   
   =item * keyword($word)
   
   Returns true if $word is a keyword.  A keyword is a word that appears more 
   than the average number of times in the thesaurus database.  Calls 
   &initialize_keywords
   
   =cut
   
   ###################################################
   
   sub keyword {
       return if (!&initialize_keywords());
       my $word=lc(shift());
       $word=~s/\W//g;
       return exists($Keywords{$word});
   }
   
   ###############################################################
   
   =pod 
   
   =item * get_related_words
   
   Look up a word in the thesaurus.  Takes a scalar argument and returns
   an array of words.  If the keyword is not in the thesaurus, an empty array
   will be returned.  The order of the words returned is determined by the
   database which holds them.
   
   Uses global $thesaurus_db_file.
   
   =cut
   
   ###############################################################
   sub get_related_words {
       my $keyword = shift;
       my %thesaurus_db;
       if (! -e $thesaurus_db_file) {
           &Apache::lonnet::logthis("Attempt to access $thesaurus_db_file ".
                                    "failed because the file does not exist");
           return ();
       }
       if (! tie(%thesaurus_db,'GDBM_File',
                 $thesaurus_db_file,&GDBM_READER(),0640)){
           return ();
       } 
       my @Words=();
       if (exists($thesaurus_db{$keyword})) {
           $_ = $thesaurus_db{$keyword};
           (undef,@Words) = split/:/;  # The first element is the number of times
                                       # the word appears.  We do not need it now.
           for (my $i=0;$i<=$#Words;$i++) {
               ($Words[$i],undef)= split/\,/,$Words[$i];
           }
       }
       untie %thesaurus_db;
       return @Words;
   }
   
   =pod
   
   =back
   
   =cut
   
   # -------------------------------------------------------------- Plaintext name
   =pod
   
   =head1 User Name Functions
   
   =over 4
   
   =item * plainname($uname,$udom)
   
   Takes a users logon name and returns it as a string in
   "first middle last generation" form
   
   =cut
   
   ###############################################################
   sub plainname {
       my ($uname,$udom)=@_;
       my %names=&Apache::lonnet::get('environment',
                       ['firstname','middlename','lastname','generation'],
    $udom,$uname);
       my $name=$names{'firstname'}.' '.$names{'middlename'}.' '.
    $names{'lastname'}.' '.$names{'generation'};
       $name=~s/\s+$//;
       $name=~s/\s+/ /g;
       return $name;
   }
   
   # -------------------------------------------------------------------- Nickname
   =pod
   
   =item * nickname($uname,$udom)
   
   Gets a users name and returns it as a string as
   
   "&quot;nickname&quot;"
   
   if the user has a nickname or
   
   "first middle last generation"
   
   if the user does not
   
   =cut
   
   sub nickname {
       my ($uname,$udom)=@_;
       my %names=&Apache::lonnet::get('environment',
     ['nickname','firstname','middlename','lastname','generation'],$udom,$uname);
       my $name=$names{'nickname'};
       if ($name) {
          $name='&quot;'.$name.'&quot;'; 
       } else {
          $name=$names{'firstname'}.' '.$names{'middlename'}.' '.
        $names{'lastname'}.' '.$names{'generation'};
          $name=~s/\s+$//;
          $name=~s/\s+/ /g;
       }
       return $name;
   }
   
   
   # ------------------------------------------------------------------ Screenname
   
   =pod
   
   =item * screenname($uname,$udom)
   
   Gets a users screenname and returns it as a string
   
   =cut
   
   sub screenname {
       my ($uname,$udom)=@_;
       my %names=
    &Apache::lonnet::get('environment',['screenname'],$udom,$uname);
       return $names{'screenname'};
   }
   
   # ------------------------------------------------------------- Message Wrapper
   
   sub messagewrapper {
       my ($link,$un,$do)=@_;
       return 
   "<a href='/adm/email?compose=individual&recname=$un&recdom=$do'>$link</a>";
   }
   # --------------------------------------------------------------- Notes Wrapper
   
   sub noteswrapper {
       my ($link,$un,$do)=@_;
       return 
   "<a href='/adm/email?recordftf=retrieve&recname=$un&recdom=$do'>$link</a>";
   }
   # ------------------------------------------------------------- Aboutme Wrapper
   
   sub aboutmewrapper {
       my ($link,$username,$domain,$target)=@_;
       return "<a href='/adm/$domain/$username/aboutme'".
    ($target?" target='$target'":'').">$link</a>";
   }
   
   # ------------------------------------------------------------ Syllabus Wrapper
   
   
   sub syllabuswrapper {
       my ($linktext,$coursedir,$domain,$fontcolor)=@_;
       if ($fontcolor) { 
           $linktext='<font color="'.$fontcolor.'">'.$linktext.'</font>'; 
       }
       return "<a href='/public/$domain/$coursedir/syllabus'>$linktext</a>";
 }  }
   
 # ---------------------------------------------------------------- Language IDs  =pod
   
   =back
   
   =head1 Access .tab File Data
   
   =over 4
   
   =item * languageids() 
   
   returns list of all language ids
   
   =cut
   
 sub languageids {  sub languageids {
     return sort(keys(%language));      return sort(keys(%language));
 }  }
   
 # -------------------------------------------------------- Language Description  =pod
   
   =item * languagedescription() 
   
   returns description of a specified language id
   
   =cut
   
 sub languagedescription {  sub languagedescription {
     return $language{shift(@_)};      my $code=shift;
       return  ($supported_language{$code}?'* ':'').
               $language{$code}.
       ($supported_language{$code}?' ('.&mt('interface available').')':'');
   }
   
   sub plainlanguagedescription {
       my $code=shift;
       return $language{$code};
 }  }
   
 # --------------------------------------------------------------- Copyright IDs  sub supportedlanguagecode {
       my $code=shift;
       return $supported_language{$code};
   }
   
   =pod
   
   =item * copyrightids() 
   
   returns list of all copyrights
   
   =cut
   
 sub copyrightids {  sub copyrightids {
     return sort(keys(%cprtag));      return sort(keys(%cprtag));
 }  }
   
 # ------------------------------------------------------- Copyright Description  =pod
   
   =item * copyrightdescription() 
   
   returns description of a specified copyright id
   
   =cut
   
 sub copyrightdescription {  sub copyrightdescription {
     return $cprtag{shift(@_)};      return &mt($cprtag{shift(@_)});
 }  }
   
 # ------------------------------------------------------------- File Categories  =pod
   
   =item * filecategories() 
   
   returns list of all file categories
   
   =cut
   
 sub filecategories {  sub filecategories {
     return sort(keys(%fc));      return sort(keys(%category_extensions));
 }  }
   
 # -------------------------------------- File Types within a specified category  =pod
   
   =item * filecategorytypes() 
   
   returns list of file types belonging to a given file
   category
   
   =cut
   
 sub filecategorytypes {  sub filecategorytypes {
     return @{$fc{lc(shift(@_))}};      return @{$category_extensions{lc($_[0])}};
 }  }
   
 # ------------------------------------------------------------------ File Types  =pod
 sub fileextensions {  
     return sort(keys(%fe));  =item * fileembstyle() 
 }  
   returns embedding style for a specified file type
   
   =cut
   
 # ------------------------------------------------------------- Embedding Style  
 sub fileembstyle {  sub fileembstyle {
     return $fe{lc(shift(@_))};      return $fe{lc(shift(@_))};
 }  }
   
 # ------------------------------------------------------------ Description Text  
   sub filecategoryselect {
       my ($name,$value)=@_;
       return &select_form($name,$value,
    '' => &mt('Any category'),
    map { $_,$_ } sort(keys(%category_extensions)));
   }
   
   =pod
   
   =item * filedescription() 
   
   returns description for a specified file type
   
   =cut
   
 sub filedescription {  sub filedescription {
     return $fd{lc(shift(@_))};      return &mt($fd{lc(shift(@_))});
 }  }
   
 # ------------------------------------------------------------ Description Text  =pod
   
   =item * filedescriptionex() 
   
   returns description for a specified file type with
   extra formatting
   
   =cut
   
 sub filedescriptionex {  sub filedescriptionex {
     my $ex=shift;      my $ex=shift;
     return '.'.$ex.' '.$fd{lc($ex)};      return '.'.$ex.' '.&mt($fd{lc($ex)});
   }
   
   # End of .tab access
   =pod
   
   =back
   
   =cut
   
   # ------------------------------------------------------------------ File Types
   sub fileextensions {
       return sort(keys(%fe));
 }  }
   
   # ----------------------------------------------------------- Display Languages
   # returns a hash with all desired display languages
   #
   
   sub display_languages {
       my %languages=();
       foreach (&preferred_languages()) {
    $languages{$_}=1;
       }
       &get_unprocessed_cgi($ENV{'QUERY_STRING'},['displaylanguage']);
       if ($ENV{'form.displaylanguage'}) {
    foreach (split(/\s*(\,|\;|\:)\s*/,$ENV{'form.displaylanguage'})) {
       $languages{$_}=1;
           }
       }
       return %languages;
   }
   
   sub preferred_languages {
       my @languages=();
       if ($ENV{'environment.languages'}) {
    @languages=split(/\s*(\,|\;|\:)\s*/,$ENV{'environment.languages'});
       }
       if ($ENV{'course.'.$ENV{'request.course.id'}.'.languages'}) {
    @languages=(@languages,split(/\s*(\,|\;|\:)\s*/,
            $ENV{'course.'.$ENV{'request.course.id'}.'.languages'}));
       }
       my $browser=(split(/\;/,$ENV{'HTTP_ACCEPT_LANGUAGE'}))[0];
       if ($browser) {
    @languages=(@languages,split(/\s*(\,|\;|\:)\s*/,$browser));
       }
       if ($Apache::lonnet::domain_lang_def{$ENV{'user.domain'}}) {
    @languages=(@languages,
    $Apache::lonnet::domain_lang_def{$ENV{'user.domain'}});
       }
       if ($Apache::lonnet::domain_lang_def{$ENV{'request.role.domain'}}) {
    @languages=(@languages,
    $Apache::lonnet::domain_lang_def{$ENV{'request.role.domain'}});
       }
       if ($Apache::lonnet::domain_lang_def{
                             $Apache::lonnet::perlvar{'lonDefDomain'}}) {
    @languages=(@languages,
    $Apache::lonnet::domain_lang_def{
                                     $Apache::lonnet::perlvar{'lonDefDomain'}});
       }
   # turn "en-ca" into "en-ca,en"
       my @genlanguages;
       foreach (@languages) {
    unless ($_=~/\w/) { next; }
    push (@genlanguages,$_);
    if ($_=~/(\-|\_)/) {
       push (@genlanguages,(split(/(\-|\_)/,$_))[0]);
    }
       }
       return @genlanguages;
   }
   
   ###############################################################
   ##               Student Answer Attempts                     ##
   ###############################################################
   
   =pod
   
   =head1 Alternate Problem Views
   
   =over 4
   
   =item * get_previous_attempt($symb, $username, $domain, $course,
       $getattempt, $regexp, $gradesub)
   
   Return string with previous attempt on problem. Arguments:
   
   =over 4
   
   =item * $symb: Problem, including path
   
   =item * $username: username of the desired student
   
   =item * $domain: domain of the desired student
   
   =item * $course: Course ID
   
   =item * $getattempt: Leave blank for all attempts, otherwise put
       something
   
   =item * $regexp: if string matches this regexp, the string will be
       sent to $gradesub
   
   =item * $gradesub: routine that processes the string if it matches $regexp
   
   =back
   
   The output string is a table containing all desired attempts, if any.
   
   =cut
   
 sub get_previous_attempt {  sub get_previous_attempt {
   my ($symb,$username,$domain,$course)=@_;    my ($symb,$username,$domain,$course,$getattempt,$regexp,$gradesub)=@_;
   my $prevattempts='';    my $prevattempts='';
     no strict 'refs';
   if ($symb) {    if ($symb) {
     my (%returnhash)=      my (%returnhash)=
       &Apache::lonnet::restore($symb,$course,$domain,$username);        &Apache::lonnet::restore($symb,$course,$domain,$username);
Line 271  sub get_previous_attempt { Line 1827  sub get_previous_attempt {
   $lasthash{$_}=$returnhash{$version.':'.$_};    $lasthash{$_}=$returnhash{$version.':'.$_};
         }          }
       }        }
       $prevattempts='<table border=2></tr><th>History</th>';        $prevattempts='<table border="0" width="100%"><tr><td bgcolor="#777777">';
         $prevattempts.='<table border="0" width="100%"><tr bgcolor="#e6ffff"><td>History</td>';
       foreach (sort(keys %lasthash)) {        foreach (sort(keys %lasthash)) {
         $prevattempts.='<th>'.$_.'</th>';   my ($ign,@parts) = split(/\./,$_);
       }   if ($#parts > 0) {
       for ($version=1;$version<=$returnhash{'version'};$version++) {    my $data=$parts[-1];
         $prevattempts.='</tr><tr><th>Attempt '.$version.'</th>';    pop(@parts);
         foreach (sort(keys %lasthash)) {    $prevattempts.='<td>Part '.join('.',@parts).'<br />'.$data.'&nbsp;</td>';
   my $value;   } else {
   if ($_ =~ /timestamp/) {    if ($#parts == 0) {
     $value=scalar(localtime($returnhash{$version.':'.$_}));      $prevattempts.='<th>'.$parts[0].'</th>';
   } else {    } else {
     $value=$returnhash{$version.':'.$_};      $prevattempts.='<th>'.$ign.'</th>';
   }    }
   $prevattempts.='<td>'.$value.'</td>';      }
         }        }
         if ($getattempt eq '') {
    for ($version=1;$version<=$returnhash{'version'};$version++) {
     $prevattempts.='</tr><tr bgcolor="#ffffe6"><td>Transaction '.$version.'</td>';
       foreach (sort(keys %lasthash)) {
          my $value;
          if ($_ =~ /timestamp/) {
     $value=scalar(localtime($returnhash{$version.':'.$_}));
          } else {
     $value=$returnhash{$version.':'.$_};
          }
          $prevattempts.='<td>'.&Apache::lonnet::unescape($value).'&nbsp;</td>';   
       }
    }
       }        }
       $prevattempts.='</tr><tr><th>Current</th>';        $prevattempts.='</tr><tr bgcolor="#ffffe6"><td>Current</td>';
       foreach (sort(keys %lasthash)) {        foreach (sort(keys %lasthash)) {
  my $value;   my $value;
  if ($_ =~ /timestamp/) {   if ($_ =~ /timestamp/) {
Line 295  sub get_previous_attempt { Line 1865  sub get_previous_attempt {
  } else {   } else {
   $value=$lasthash{$_};    $value=$lasthash{$_};
  }   }
  $prevattempts.='<td>'.$value.'</td>';   $value=&Apache::lonnet::unescape($value);
    if ($_ =~/$regexp$/ && (defined &$gradesub)) {$value = &$gradesub($value)}
    $prevattempts.='<td>'.$value.'&nbsp;</td>';
       }        }
       $prevattempts.='</tr></table>';        $prevattempts.='</tr></table></td></tr></table>';
     } else {      } else {
       $prevattempts='Nothing submitted - no attempts.';        $prevattempts='Nothing submitted - no attempts.';
     }      }
Line 306  sub get_previous_attempt { Line 1878  sub get_previous_attempt {
   }    }
 }  }
   
   sub relative_to_absolute {
       my ($url,$output)=@_;
       my $parser=HTML::TokeParser->new(\$output);
       my $token;
       my $thisdir=$url;
       my @rlinks=();
       while ($token=$parser->get_token) {
    if ($token->[0] eq 'S') {
       if ($token->[1] eq 'a') {
    if ($token->[2]->{'href'}) {
       $rlinks[$#rlinks+1]=$token->[2]->{'href'};
    }
       } elsif ($token->[1] eq 'img' || $token->[1] eq 'embed' ) {
    $rlinks[$#rlinks+1]=$token->[2]->{'src'};
       } elsif ($token->[1] eq 'base') {
    $thisdir=$token->[2]->{'href'};
       }
    }
       }
       $thisdir=~s-/[^/]*$--;
       foreach (@rlinks) {
    unless (($_=~/^http:\/\//i) ||
    ($_=~/^\//) ||
    ($_=~/^javascript:/i) ||
    ($_=~/^mailto:/i) ||
    ($_=~/^\#/)) {
       my $newlocation=&Apache::lonnet::hreflocation($thisdir,$_);
       $output=~s/(\"|\'|\=\s*)$_(\"|\'|\s|\>)/$1$newlocation$2/;
    }
       }
   # -------------------------------------------------- Deal with Applet codebases
       $output=~s/(\<applet[^\>]+)(codebase\=[^\S\>]+)*([^\>]*)\>/$1.($2?$2:' codebase="'.$thisdir.'"').$3.'>'/gei;
       return $output;
   }
   
   =pod
   
   =item * get_student_view
   
   show a snapshot of what student was looking at
   
   =cut
   
 sub get_student_view {  sub get_student_view {
   my ($symb,$username,$domain,$courseid) = @_;    my ($symb,$username,$domain,$courseid,$target) = @_;
   my ($map,$id,$feedurl) = split(/___/,$symb);    my ($map,$id,$feedurl) = &Apache::lonnet::decode_symb($symb);
   my (%old,%moreenv);    my (%old,%moreenv);
   my @elements=('symb','courseid','domain','username');    my @elements=('symb','courseid','domain','username');
   foreach my $element (@elements) {    foreach my $element (@elements) {
     $old{$element}=$ENV{'form.grade_'.$element};      $old{$element}=$ENV{'form.grade_'.$element};
     $moreenv{'form.grade_'.$element}=eval '$'.$element #'      $moreenv{'form.grade_'.$element}=eval '$'.$element #'
   }    }
     if ($target eq 'tex') {$moreenv{'form.grade_target'} = 'tex';}
   &Apache::lonnet::appenv(%moreenv);    &Apache::lonnet::appenv(%moreenv);
   my $userview=&Apache::lonnet::ssi('/res/'.$feedurl);    $feedurl=&Apache::lonnet::clutter($feedurl);
     my $userview=&Apache::lonnet::ssi_body($feedurl);
   &Apache::lonnet::delenv('form.grade_');    &Apache::lonnet::delenv('form.grade_');
   foreach my $element (@elements) {    foreach my $element (@elements) {
     $ENV{'form.grade_'.$element}=$old{$element};      $ENV{'form.grade_'.$element}=$old{$element};
Line 328  sub get_student_view { Line 1945  sub get_student_view {
   $userview=~s/\<head\>//gi;    $userview=~s/\<head\>//gi;
   $userview=~s/\<\/head\>//gi;    $userview=~s/\<\/head\>//gi;
   $userview=~s/action\s*\=/would_be_action\=/gi;    $userview=~s/action\s*\=/would_be_action\=/gi;
     $userview=&relative_to_absolute($feedurl,$userview);
   return $userview;    return $userview;
 }  }
   
   =pod
   
   =item * get_student_answers() 
   
   show a snapshot of how student was answering problem
   
   =cut
   
 sub get_student_answers {  sub get_student_answers {
   my ($symb,$username,$domain,$courseid) = @_;    my ($symb,$username,$domain,$courseid,%form) = @_;
   my ($map,$id,$feedurl) = split(/___/,$symb);    my ($map,$id,$feedurl) = &Apache::lonnet::decode_symb($symb);
   my (%old,%moreenv);    my (%old,%moreenv);
   my @elements=('symb','courseid','domain','username');    my @elements=('symb','courseid','domain','username');
   foreach my $element (@elements) {    foreach my $element (@elements) {
Line 342  sub get_student_answers { Line 1968  sub get_student_answers {
   }    }
   $moreenv{'form.grade_target'}='answer';    $moreenv{'form.grade_target'}='answer';
   &Apache::lonnet::appenv(%moreenv);    &Apache::lonnet::appenv(%moreenv);
   my $userview=&Apache::lonnet::ssi('/res/'.$feedurl);    my $userview=&Apache::lonnet::ssi('/res/'.$feedurl,%form);
   &Apache::lonnet::delenv('form.grade_');    &Apache::lonnet::delenv('form.grade_');
   foreach my $element (@elements) {    foreach my $element (@elements) {
     $ENV{'form.grade_'.$element}=$old{$element};      $ENV{'form.grade_'.$element}=$old{$element};
   }    }
   $userview=~s/\<body[^\>]*\>//gi;  
   $userview=~s/\<\/body\>//gi;  
   $userview=~s/\<html\>//gi;  
   $userview=~s/\<\/html\>//gi;  
   $userview=~s/\<head\>//gi;  
   $userview=~s/\<\/head\>//gi;  
   $userview=~s/action\s*\=/would_be_action\=/gi;  
   return $userview;    return $userview;
 }  }
   
   =pod
   
   =item * &submlink()
   
   Inputs: $text $uname $udom $symb
   
   Returns: A link to grades.pm such as to see the SUBM view of a student
   
   =cut
   
   ###############################################
   sub submlink {
       my ($text,$uname,$udom,$symb)=@_;
       if (!($uname && $udom)) {
    (my $cursymb, my $courseid,$udom,$uname)=
       &Apache::lonxml::whichuser($symb);
    if (!$symb) { $symb=$cursymb; }
       }
       if (!$symb) { $symb=&symbread(); }
       return '<a href="/adm/grades?symb='.$symb.'&student='.$uname.
    '&userdom='.$udom.'&command=submission">'.$text.'</a>';
   }
   ##############################################
   
   =pod
   
   =back
   
   =cut
   
   ###############################################
   
   
   sub timehash {
       my @ltime=localtime(shift);
       return ( 'seconds' => $ltime[0],
                'minutes' => $ltime[1],
                'hours'   => $ltime[2],
                'day'     => $ltime[3],
                'month'   => $ltime[4]+1,
                'year'    => $ltime[5]+1900,
                'weekday' => $ltime[6],
                'dayyear' => $ltime[7]+1,
                'dlsav'   => $ltime[8] );
   }
   
   sub maketime {
       my %th=@_;
       return POSIX::mktime(
           ($th{'seconds'},$th{'minutes'},$th{'hours'},
            $th{'day'},$th{'month'}-1,$th{'year'}-1900,0,0,$th{'dlsav'}));
   }
   
   #########################################
   
   sub findallcourses {
       my %courses=();
       my $now=time;
       foreach (keys %ENV) {
    if ($_=~/^user\.role\.\w+\.\/(\w+)\/(\w+)/) {
       my ($starttime,$endtime)=$ENV{$_};
               my $active=1;
               if ($starttime) {
    if ($now<$starttime) { $active=0; }
               }
               if ($endtime) {
                   if ($now>$endtime) { $active=0; }
               }
               if ($active) { $courses{$1.'_'.$2}=1; }
           }
       }
       return keys %courses;
   }
   
   ###############################################
   ###############################################
   
   =pod
   
   =head1 Domain Template Functions
   
   =over 4
   
   =item * &determinedomain()
   
   Inputs: $domain (usually will be undef)
   
   Returns: Determines which domain should be used for designs
   
   =cut
   
   ###############################################
   sub determinedomain {
       my $domain=shift;
      if (! $domain) {
           # Determine domain if we have not been given one
           $domain = $Apache::lonnet::perlvar{'lonDefDomain'};
           if ($ENV{'user.domain'}) { $domain=$ENV{'user.domain'}; }
           if ($ENV{'request.role.domain'}) { 
               $domain=$ENV{'request.role.domain'}; 
           }
       }
       return $domain;
   }
   ###############################################
   =pod
   
   =item * &domainlogo()
   
   Inputs: $domain (usually will be undef)
   
   Returns: A link to a domain logo, if the domain logo exists.
   If the domain logo does not exist, a description of the domain.
   
   =cut
   
   ###############################################
   sub domainlogo {
       my $domain = &determinedomain(shift);    
        # See if there is a logo
       if (-e '/home/httpd/html/adm/lonDomLogos/'.$domain.'.gif') {
    my $lonhttpdPort=$Apache::lonnet::perlvar{'lonhttpdPort'};
    if (!defined($lonhttpdPort)) { $lonhttpdPort='8080'; }
           return '<img src="http://'.$ENV{'HTTP_HOST'}.':'.$lonhttpdPort.
       '/adm/lonDomLogos/'.$domain.'.gif" alt="'.$domain.'" />';
       } elsif(exists($Apache::lonnet::domaindescription{$domain})) {
           return $Apache::lonnet::domaindescription{$domain};
       } else {
           return '';
       }
   }
   ##############################################
   
   =pod
   
   =item * &designparm()
   
   Inputs: $which parameter; $domain (usually will be undef)
   
   Returns: value of designparamter $which
   
   =cut
   
   ##############################################
   sub designparm {
       my ($which,$domain)=@_;
       if ($ENV{'browser.blackwhite'} eq 'on') {
    if ($which=~/\.(font|alink|vlink|link)$/) {
       return '#000000';
    }
    if ($which=~/\.(pgbg|sidebg)$/) {
       return '#FFFFFF';
    }
    if ($which=~/\.tabbg$/) {
       return '#CCCCCC';
    }
       }
       if ($ENV{'environment.color.'.$which}) {
    return $ENV{'environment.color.'.$which};
       }
       $domain=&determinedomain($domain);
       if ($designhash{$domain.'.'.$which}) {
    return $designhash{$domain.'.'.$which};
       } else {
           return $designhash{'default.'.$which};
       }
   }
   
   ###############################################
   ###############################################
   
   =pod
   
   =back
   
   =head1 HTTP Helpers
   
   =over 4
   
   =item * &bodytag()
   
   Returns a uniform header for LON-CAPA web pages.
   
   Inputs: 
   
   =over 4
   
   =item * $title, A title to be displayed on the page.
   
   =item * $function, the current role (can be undef).
   
   =item * $addentries, extra parameters for the <body> tag.
   
   =item * $bodyonly, if defined, only return the <body> tag.
   
   =item * $domain, if defined, force a given domain.
   
   =item * $forcereg, if page should register as content page (relevant for 
               text interface only)
   
   =back
   
   Returns: A uniform header for LON-CAPA web pages.  
   If $bodyonly is nonzero, a string containing a <body> tag will be returned.
   If $bodyonly is undef or zero, an html string containing a <body> tag and 
   other decorations will be returned.
   
   =cut
   
   sub bodytag {
       my ($title,$function,$addentries,$bodyonly,$domain,$forcereg)=@_;
       $title=&mt($title);
       unless ($function) {
    $function='student';
           if ($ENV{'request.role'}=~/^(cc|in|ta|ep)/) {
       $function='coordinator';
           }
    if ($ENV{'request.role'}=~/^(su|dc|ad|li)/) {
               $function='admin';
           }
           if (($ENV{'request.role'}=~/^(au|ca)/) ||
               ($ENV{'REQUEST_URI'}=~/^(\/priv|\~)/)) {
               $function='author';
           }
       }
       my $img=&designparm($function.'.img',$domain);
       my $pgbg=&designparm($function.'.pgbg',$domain);
       my $tabbg=&designparm($function.'.tabbg',$domain);
       my $font=&designparm($function.'.font',$domain);
       my $link=&designparm($function.'.link',$domain);
       my $alink=&designparm($function.'.alink',$domain);
       my $vlink=&designparm($function.'.vlink',$domain);
       my $sidebg=&designparm($function.'.sidebg',$domain);
   # Accessibility font enhance
       unless ($addentries) { $addentries=''; }
       my $addstyle='';
       if ($ENV{'browser.fontenhance'} eq 'on') {
    $addstyle=' font-size: x-large;';
       }
    # role and realm
       my ($role,$realm)
          =&Apache::lonnet::plaintext((split(/\./,$ENV{'request.role'}))[0]);
   # realm
       if ($ENV{'request.course.id'}) {
    $realm=
            $ENV{'course.'.$ENV{'request.course.id'}.'.description'};
       }
       unless ($realm) { $realm='&nbsp;'; }
   # Set messages
       my $messages=&domainlogo($domain);
   # Port for miniserver
       my $lonhttpdPort=$Apache::lonnet::perlvar{'lonhttpdPort'};
       if (!defined($lonhttpdPort)) { $lonhttpdPort='8080'; }
   # construct main body tag
       my $bodytag = <<END;
   <style>
   h1, h2, h3, th { font-family: Arial, Helvetica, sans-serif }
   a:focus { color: red; background: yellow } 
   </style>
   <body bgcolor="$pgbg" text="$font" alink="$alink" vlink="$vlink" link="$link"
   style="margin-top: 0px;$addstyle" $addentries>
   END
       my $upperleft='<img src="http://'.$ENV{'HTTP_HOST'}.':'.
                      $lonhttpdPort.$img.'" alt="'.$function.'" />';
       if ($bodyonly) {
           return $bodytag;
       } elsif ($ENV{'browser.interface'} eq 'textual') {
   # Accessibility
           return $bodytag.&Apache::lonmenu::menubuttons($forcereg,'web',
                                                         $forcereg).
                  '<h1>LON-CAPA: '.$title.'</h1>';
       } elsif ($ENV{'environment.remote'} eq 'off') {
   # No Remote
           return $bodytag.&Apache::lonmenu::menubuttons($forcereg,'web',
                                                         $forcereg).
         '<table bgcolor="'.$pgbg.'" width="100%" border="0" cellspacing="3" cellpadding="3"><tr><td bgcolor="'.$tabbg.'"><font face="Arial, Helvetica, sans-serif" size="+3" color="'.$font.'"><b>'.$title.
   '</b></font></td></tr></table>';
       }
   
   #
   # Top frame rendering, Remote is up
   #
       return(<<ENDBODY);
   $bodytag
   <table width="100%" cellspacing="0" border="0" cellpadding="0">
   <tr><td bgcolor="$sidebg">
   $upperleft</td>
   <td bgcolor="$sidebg" align="right">$messages&nbsp;</td>
   </tr>
   <tr>
   <td rowspan="3" bgcolor="$tabbg">
   &nbsp;<font size="5" face="Arial, Helvetica, sans-serif"><b>$title</b></font>
   <td bgcolor="$tabbg" align="right">
   <font size="2" face="Arial, Helvetica, sans-serif">
       $ENV{'environment.firstname'}
       $ENV{'environment.middlename'}
       $ENV{'environment.lastname'}
       $ENV{'environment.generation'}
       </font>&nbsp;
   </td>
   </tr>
   <tr><td bgcolor="$tabbg" align="right">
   <font size="2" face="Arial, Helvetica, sans-serif">$role</font>&nbsp;
   </td></tr>
   <tr>
   <td bgcolor="$tabbg" align="right"><font size="2" face="Arial, Helvetica, sans-serif">$realm</font>&nbsp;</td></tr>
   </table><br>
   ENDBODY
   }
   
   ###############################################
   
   sub get_posted_cgi {
       my $r=shift;
   
       my $buffer;
       
       $r->read($buffer,$r->header_in('Content-length'),0);
       unless ($buffer=~/^(\-+\w+)\s+Content\-Disposition\:\s*form\-data/si) {
    my @pairs=split(/&/,$buffer);
    my $pair;
    foreach $pair (@pairs) {
       my ($name,$value) = split(/=/,$pair);
       $value =~ tr/+/ /;
       $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
       $name  =~ tr/+/ /;
       $name  =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
       &add_to_env("form.$name",$value);
    }
       } else {
    my $contentsep=$1;
    my @lines = split (/\n/,$buffer);
    my $name='';
    my $value='';
    my $fname='';
    my $fmime='';
    my $i;
    for ($i=0;$i<=$#lines;$i++) {
       if ($lines[$i]=~/^$contentsep/) {
    if ($name) {
       chomp($value);
       if ($fname) {
    $ENV{"form.$name.filename"}=$fname;
    $ENV{"form.$name.mimetype"}=$fmime;
       } else {
    $value=~s/\s+$//s;
       }
       &add_to_env("form.$name",$value);
    }
    if ($i<$#lines) {
       $i++;
       $lines[$i]=~
    /Content\-Disposition\:\s*form\-data\;\s*name\=\"([^\"]+)\"/i;
       $name=$1;
       $value='';
       if ($lines[$i]=~/filename\=\"([^\"]+)\"/i) {
    $fname=$1;
    if 
                               ($lines[$i+1]=~/Content\-Type\:\s*([\w\-\/]+)/i) {
    $fmime=$1;
    $i++;
       } else {
    $fmime='';
       }
       } else {
    $fname='';
    $fmime='';
       }
       $i++;
    }
       } else {
    $value.=$lines[$i]."\n";
       }
    }
       }
       $ENV{'request.method'}=$ENV{'REQUEST_METHOD'};
       $r->method_number(M_GET);
       $r->method('GET');
       $r->headers_in->unset('Content-length');
   }
   
   =pod
   
   =item * get_unprocessed_cgi($query,$possible_names)
   
   Modify the %ENV hash to contain unprocessed CGI form parameters held in
   $query.  The parameters listed in $possible_names (an array reference),
   will be set in $ENV{'form.name'} if they do not already exist.
   
   Typically called with $ENV{'QUERY_STRING'} as the first parameter.  
   $possible_names is an ref to an array of form element names.  As an example:
   get_unprocessed_cgi($ENV{'QUERY_STRING'},['uname','udom']);
   will result in $ENV{'form.uname'} and $ENV{'form.udom'} being set.
   
   =cut
   
 sub get_unprocessed_cgi {  sub get_unprocessed_cgi {
   my ($query,$possible_names)= @_;    my ($query,$possible_names)= @_;
   $Apache::lonxml::debug=1;    # $Apache::lonxml::debug=1;
   foreach (split(/&/,$query)) {    foreach (split(/&/,$query)) {
     my ($name, $value) = split(/=/,$_);      my ($name, $value) = split(/=/,$_);
     $name = &Apache::lonnet::unescape($name);      $name = &Apache::lonnet::unescape($name);
Line 367  sub get_unprocessed_cgi { Line 2382  sub get_unprocessed_cgi {
       $value =~ tr/+/ /;        $value =~ tr/+/ /;
       $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;        $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
       &Apache::lonxml::debug("Seting :$name: to :$value:");        &Apache::lonxml::debug("Seting :$name: to :$value:");
       &add_to_env('form.'.$name,$value);        unless (defined($ENV{'form.'.$name})) { &add_to_env('form.'.$name,$value) };
     }      }
   }    }
 }  }
   
   =pod
   
   =item * cacheheader() 
   
   returns cache-controlling header code
   
   =cut
   
 sub cacheheader {  sub cacheheader {
   unless ($ENV{'request.method'} eq 'GET') { return ''; }    unless ($ENV{'request.method'} eq 'GET') { return ''; }
   my $date=strftime("%a, %d %b %Y %H:%M:%S GMT",gmtime);    my $date=strftime("%a, %d %b %Y %H:%M:%S GMT",gmtime);
Line 381  sub cacheheader { Line 2404  sub cacheheader {
   return $output;    return $output;
 }  }
   
   =pod
   
   =item * no_cache($r) 
   
   specifies header code to not have cache
   
   =cut
   
 sub no_cache {  sub no_cache {
   my ($r) = @_;    my ($r) = @_;
   unless ($ENV{'request.method'} eq 'GET') { return ''; }    unless ($ENV{'request.method'} eq 'GET') { return ''; }
Line 390  sub no_cache { Line 2421  sub no_cache {
   #$r->header_out("Expires" => $date);    #$r->header_out("Expires" => $date);
 }  }
   
   sub content_type {
     my ($r,$type,$charset) = @_;
     unless ($charset) {
         $charset=&Apache::lonlocal::current_encoding;
     }
     $r->content_type($type.($charset?'; charset='.$charset:''));
   }
   
   =pod
   
   =item * add_to_env($name,$value) 
   
   adds $name to the %ENV hash with value
   $value, if $name already exists, the entry is converted to an array
   reference and $value is added to the array.
   
   =cut
   
 sub add_to_env {  sub add_to_env {
   my ($name,$value)=@_;    my ($name,$value)=@_;
   if ($ENV{$name}) {    if (defined($ENV{$name})) {
     if (defined(@{ $ENV{$name} })) {      if (ref($ENV{$name})) {
       #already have multiple values        #already have multiple values
       push(@{ $ENV{$name} },$value);        push(@{ $ENV{$name} },$value);
     } else {      } else {
Line 406  sub add_to_env { Line 2455  sub add_to_env {
     $ENV{$name}=$value;      $ENV{$name}=$value;
   }    }
 }  }
 1;  
 __END__;  
   
   =pod
   
 =head1 NAME  =item * get_env_multiple($name) 
   
 Apache::loncommon - pile of common routines  gets $name from the %ENV hash, it seemlessly handles the cases where multiple
   values may be defined and end up as an array ref.
   
 =head1 SYNOPSIS  returns an array of values
   
 Referenced by other mod_perl Apache modules.  =cut
   
 Invocation:  sub get_env_multiple {
  &Apache::loncommon::SUBROUTINENAME(ARGUMENTS);      my ($name) = @_;
       my @values;
       if (defined($ENV{$name})) {
           # exists is it an array
           if (ref($ENV{$name})) {
               @values=@{ $ENV{$name} };
           } else {
               $values[0]=$ENV{$name};
           }
       }
       return(@values);
   }
   
 =head1 INTRODUCTION  
   
 Common collection of used subroutines.  This collection helps remove  =pod
 redundancy from other modules and increase efficiency of memory usage.  
   =back 
   
   =head1 CSV Upload/Handling functions
   
   =over 4
   
   =item * upfile_store($r)
   
   Store uploaded file, $r should be the HTTP Request object,
   needs $ENV{'form.upfile'}
   returns $datatoken to be put into hidden field
   
   =cut
   
   sub upfile_store {
       my $r=shift;
       $ENV{'form.upfile'}=~s/\r/\n/gs;
       $ENV{'form.upfile'}=~s/\f/\n/gs;
       $ENV{'form.upfile'}=~s/\n+/\n/gs;
       $ENV{'form.upfile'}=~s/\n+$//gs;
   
       my $datatoken=$ENV{'user.name'}.'_'.$ENV{'user.domain'}.
    '_enroll_'.$ENV{'request.course.id'}.'_'.time.'_'.$$;
       {
           my $datafile = $r->dir_config('lonDaemons').
                              '/tmp/'.$datatoken.'.tmp';
           if ( open(my $fh,">$datafile") ) {
               print $fh $ENV{'form.upfile'};
               close($fh);
           }
       }
       return $datatoken;
   }
   
   =pod
   
   =item * load_tmp_file($r)
   
   Load uploaded file from tmp, $r should be the HTTP Request object,
   needs $ENV{'form.datatoken'},
   sets $ENV{'form.upfile'} to the contents of the file
   
   =cut
   
   sub load_tmp_file {
       my $r=shift;
       my @studentdata=();
       {
           my $studentfile = $r->dir_config('lonDaemons').
                                 '/tmp/'.$ENV{'form.datatoken'}.'.tmp';
           if ( open(my $fh,"<$studentfile") ) {
               @studentdata=<$fh>;
               close($fh);
           }
       }
       $ENV{'form.upfile'}=join('',@studentdata);
   }
   
   =pod
   
   =item * upfile_record_sep()
   
   Separate uploaded file into records
   returns array of records,
   needs $ENV{'form.upfile'} and $ENV{'form.upfiletype'}
   
   =cut
   
   sub upfile_record_sep {
       if ($ENV{'form.upfiletype'} eq 'xml') {
       } else {
    return split(/\n/,$ENV{'form.upfile'});
       }
   }
   
   =pod
   
   =item * record_sep($record)
   
   Separate a record into fields $record should be an item from the upfile_record_sep(), needs $ENV{'form.upfiletype'}
   
   =cut
   
   sub record_sep {
       my $record=shift;
       my %components=();
       if ($ENV{'form.upfiletype'} eq 'xml') {
       } elsif ($ENV{'form.upfiletype'} eq 'space') {
           my $i=0;
           foreach (split(/\s+/,$record)) {
               my $field=$_;
               $field=~s/^(\"|\')//;
               $field=~s/(\"|\')$//;
               $components{$i}=$field;
               $i++;
           }
       } elsif ($ENV{'form.upfiletype'} eq 'tab') {
           my $i=0;
           foreach (split(/\t+/,$record)) {
               my $field=$_;
               $field=~s/^(\"|\')//;
               $field=~s/(\"|\')$//;
               $components{$i}=$field;
               $i++;
           }
       } else {
           my @allfields=split(/\,/,$record);
           my $i=0;
           my $j;
           for ($j=0;$j<=$#allfields;$j++) {
               my $field=$allfields[$j];
               if ($field=~/^\s*(\"|\')/) {
    my $delimiter=$1;
                   while (($field!~/$delimiter$/) && ($j<$#allfields)) {
       $j++;
       $field.=','.$allfields[$j];
    }
                   $field=~s/^\s*$delimiter//;
                   $field=~s/$delimiter\s*$//;
               }
               $components{$i}=$field;
       $i++;
           }
       }
       return %components;
   }
   
   ######################################################
   ######################################################
   
   =pod
   
   =item * upfile_select_html()
   
   Return HTML code to select a file from the users machine and specify 
   the file type.
   
   =cut
   
   ######################################################
   ######################################################
   sub upfile_select_html {
       my %Types = (
                    csv   => &mt('CSV (comma separated values, spreadsheet)'),
                    space => &mt('Space separated'),
                    tab   => &mt('Tabulator separated'),
   #                 xml   => &mt('HTML/XML'),
                    );
       my $Str = '<input type="file" name="upfile" size="50" />'.
           '<br />Type: <select name="upfiletype">';
       foreach my $type (sort(keys(%Types))) {
           $Str .= '<option value="'.$type.'" >'.$Types{$type}."</option>\n";
       }
       $Str .= "</select>\n";
       return $Str;
   }
   
   ######################################################
   ######################################################
   
   =pod
   
   =item * csv_print_samples($r,$records)
   
   Prints a table of sample values from each column uploaded $r is an
   Apache Request ref, $records is an arrayref from
   &Apache::loncommon::upfile_record_sep
   
   =cut
   
   ######################################################
   ######################################################
   sub csv_print_samples {
       my ($r,$records) = @_;
       my (%sone,%stwo,%sthree);
       %sone=&record_sep($$records[0]);
       if (defined($$records[1])) {%stwo=&record_sep($$records[1]);}
       if (defined($$records[2])) {%sthree=&record_sep($$records[2]);}
       #
       $r->print(&mt('Samples').'<br /><table border="2"><tr>');
       foreach (sort({$a <=> $b} keys(%sone))) { 
           $r->print('<th>'.&mt('Column&nbsp;[_1]',($_+1)).'</th>'); }
       $r->print('</tr>');
       foreach my $hash (\%sone,\%stwo,\%sthree) {
    $r->print('<tr>');
    foreach (sort({$a <=> $b} keys(%sone))) {
       $r->print('<td>');
       if (defined($$hash{$_})) { $r->print($$hash{$_}); }
       $r->print('</td>');
    }
    $r->print('</tr>');
       }
       $r->print('</tr></table><br />'."\n");
   }
   
   ######################################################
   ######################################################
   
   =pod
   
   =item * csv_print_select_table($r,$records,$d)
   
   Prints a table to create associations between values and table columns.
   
   $r is an Apache Request ref,
   $records is an arrayref from &Apache::loncommon::upfile_record_sep,
   $d is an array of 2 element arrays (internal name, displayed name)
   
   =cut
   
   ######################################################
   ######################################################
   sub csv_print_select_table {
       my ($r,$records,$d) = @_;
       my $i=0;my %sone;
       %sone=&record_sep($$records[0]);
       $r->print(&mt('Associate columns with student attributes.')."\n".
        '<table border="2"><tr>'.
                 '<th>'.&mt('Attribute').'</th>'.
                 '<th>'.&mt('Column').'</th></tr>'."\n");
       foreach (@$d) {
    my ($value,$display)=@{ $_ };
    $r->print('<tr><td>'.$display.'</td>');
   
    $r->print('<td><select name=f'.$i.
     ' onchange="javascript:flip(this.form,'.$i.');">');
    $r->print('<option value="none"></option>');
    foreach (sort({$a <=> $b} keys(%sone))) {
       $r->print('<option value="'.$_.'">Column '.($_+1).'</option>');
    }
    $r->print('</select></td></tr>'."\n");
    $i++;
       }
       $i--;
       return $i;
   }
   
   ######################################################
   ######################################################
   
   =pod
   
   =item * csv_samples_select_table($r,$records,$d)
   
   Prints a table of sample values from the upload and can make associate samples to internal names.
   
   $r is an Apache Request ref,
   $records is an arrayref from &Apache::loncommon::upfile_record_sep,
   $d is an array of 2 element arrays (internal name, displayed name)
   
   =cut
   
   ######################################################
   ######################################################
   sub csv_samples_select_table {
       my ($r,$records,$d) = @_;
       my %sone; my %stwo; my %sthree;
       my $i=0;
       #
       $r->print('<table border=2><tr><th>'.
                 &mt('Field').'</th><th>'.&mt('Samples').'</th></tr>');
       %sone=&record_sep($$records[0]);
       if (defined($$records[1])) {%stwo=&record_sep($$records[1]);}
       if (defined($$records[2])) {%sthree=&record_sep($$records[2]);}
       #
       foreach (sort keys %sone) {
    $r->print('<tr><td><select name="f'.$i.'"'.
     ' onchange="javascript:flip(this.form,'.$i.');">');
    foreach (@$d) {
       my ($value,$display)=@{ $_ };
       $r->print('<option value="'.$value.'">'.$display.'</option>');
    }
    $r->print('</select></td><td>');
    if (defined($sone{$_})) { $r->print($sone{$_}."</br>\n"); }
    if (defined($stwo{$_})) { $r->print($stwo{$_}."</br>\n"); }
    if (defined($sthree{$_})) { $r->print($sthree{$_}."</br>\n"); }
    $r->print('</td></tr>');
    $i++;
       }
       $i--;
       return($i);
   }
   
   ######################################################
   ######################################################
   
   =pod
   
   =item clean_excel_name($name)
   
   Returns a replacement for $name which does not contain any illegal characters.
   
   =cut
   
   ######################################################
   ######################################################
   sub clean_excel_name {
       my ($name) = @_;
       $name =~ s/[:\*\?\/\\]//g;
       if (length($name) > 31) {
           $name = substr($name,0,31);
       }
       return $name;
   }
   
   =pod
   
   =item * check_if_partid_hidden($id,$symb,$udom,$uname)
   
   Returns either 1 or undef
   
   1 if the part is to be hidden, undef if it is to be shown
   
   Arguments are:
   
   $id the id of the part to be checked
   $symb, optional the symb of the resource to check
   $udom, optional the domain of the user to check for
   $uname, optional the username of the user to check for
   
   =cut
   
 Current things done:  sub check_if_partid_hidden {
       my ($id,$symb,$udom,$uname) = @_;
       my $hiddenparts=&Apache::lonnet::EXT('resource.0.hiddenparts',
    $symb,$udom,$uname);
       my $truth=1;
       #if the string starts with !, then the list is the list to show not hide
       if ($hiddenparts=~s/^\s*!//) { $truth=undef; }
       my @hiddenlist=split(/,/,$hiddenparts);
       foreach my $checkid (@hiddenlist) {
    if ($checkid =~ /^\s*\Q$id\E\s*$/) { return $truth; }
       }
       return !$truth;
   }
   
  Makes a table out of the previous homework attempts  
  Inputs result_from_symbread, user, domain, course_id  
  Reads in non-network-related .tab files  
   
 This is part of the LearningOnline Network with CAPA project  ############################################################
 described at http://www.lon-capa.org.  ############################################################
   
 =head1 HANDLER SUBROUTINE  =pod
   
 There is no handler subroutine.  =back 
   
 =head1 OTHER SUBROUTINES  =head1 cgi-bin script and graphing routines
   
 =over 4  =over 4
   
 =item *  =item get_cgi_id
   
 BEGIN() : initialize values from language.tab, copyright.tab, filetypes.tab,  Inputs: none
 and filecategories.tab.  
   
 =item *  Returns an id which can be used to pass environment variables
   to various cgi-bin scripts.  These environment variables will
   be removed from the users environment after a given time by
   the routine &Apache::lonnet::transfer_profile_to_env.
   
 languageids() : returns list of all language ids  =cut
   
 =item *  ############################################################
   ############################################################
   my $uniq=0;
   sub get_cgi_id {
       $uniq=($uniq+1)%100000;
       return (time.'_'.$uniq);
   }
   
 languagedescription() : returns description of a specified language id  ############################################################
   ############################################################
   
 =item *  =pod
   
 copyrightids() : returns list of all copyrights  =item DrawBarGraph
   
 =item *  Facilitates the plotting of data in a (stacked) bar graph.
   Puts plot definition data into the users environment in order for 
   graph.png to plot it.  Returns an <img> tag for the plot.
   The bars on the plot are labeled '1','2',...,'n'.
   
 copyrightdescription() : returns description of a specified copyright id  Inputs:
   
 =item *  =over 4
   
 filecategories() : returns list of all file categories  =item $Title: string, the title of the plot
   
 =item *  =item $xlabel: string, text describing the X-axis of the plot
   
 filecategorytypes() : returns list of file types belonging to a given file  =item $ylabel: string, text describing the Y-axis of the plot
 category  
   
 =item *  =item $Max: scalar, the maximum Y value to use in the plot
   If $Max is < any data point, the graph will not be rendered.
   
 fileembstyle() : returns embedding style for a specified file type  =item $colors: array ref holding the colors to be used for the data sets when
   they are plotted.  If undefined, default values will be used.
   
 =item *  =item @Values: An array of array references.  Each array reference holds data
   to be plotted in a stacked bar chart.
   
 filedescription() : returns description for a specified file type  =back
   
 =item *  Returns:
   
 filedescriptionex() : returns description for a specified file type with  An <img> tag which references graph.png and the appropriate identifying
 extra formatting  information for the plot.
   
 =item *  =cut
   
 get_previous_attempt() : return string with previous attempt on problem  ############################################################
   ############################################################
   sub DrawBarGraph {
       my ($Title,$xlabel,$ylabel,$Max,$colors,@Values)=@_;
       #
       if (! defined($colors)) {
           $colors = ['#33ff00', 
                     '#0033cc', '#990000', '#aaaa66', '#663399', '#ff9933',
                     '#66ccff', '#ff9999', '#cccc33', '#660000', '#33cc66',
                     ]; 
       }
       #
       my $identifier = &get_cgi_id();
       my $id = 'cgi.'.$identifier;        
       if (! @Values || ref($Values[0]) ne 'ARRAY') {
           return '';
       }
       my $NumBars = scalar(@{$Values[0]});
       my %ValuesHash;
       my $NumSets=1;
       foreach my $array (@Values) {
           next if (! ref($array));
           $ValuesHash{$id.'.data.'.$NumSets++} = 
               join(',',@$array);
       }
       #
       my ($height,$width,$xskip,$bar_width) = (200,120,1,15);
       if ($NumBars < 10) {
           $width = 120+$NumBars*15;
           $xskip = 1;
           $bar_width = 15;
       } elsif ($NumBars <= 25) {
           $width = 120+$NumBars*11;
           $xskip = 5;
           $bar_width = 8;
       } elsif ($NumBars <= 50) {
           $width = 120+$NumBars*8;
           $xskip = 5;
           $bar_width = 4;
       } else {
           $width = 120+$NumBars*8;
           $xskip = 5;
           $bar_width = 4;
       }
       #
       my @Labels;
       for (my $i=0;$i<@{$Values[0]};$i++) {
           push (@Labels,$i+1);
       }
       #
       $Max = 1 if ($Max < 1);
       if ( int($Max) < $Max ) {
           $Max++;
           $Max = int($Max);
       }
       $Title  = '' if (! defined($Title));
       $xlabel = '' if (! defined($xlabel));
       $ylabel = '' if (! defined($ylabel));
       $ValuesHash{$id.'.title'}    = &Apache::lonnet::escape($Title);
       $ValuesHash{$id.'.xlabel'}   = &Apache::lonnet::escape($xlabel);
       $ValuesHash{$id.'.ylabel'}   = &Apache::lonnet::escape($ylabel);
       $ValuesHash{$id.'.y_max_value'} = $Max;
       $ValuesHash{$id.'.NumBars'}  = $NumBars;
       $ValuesHash{$id.'.NumSets'}  = $NumSets;
       $ValuesHash{$id.'.PlotType'} = 'bar';
       $ValuesHash{$id.'.Colors'}   = join(',',@{$colors});
       $ValuesHash{$id.'.height'}   = $height;
       $ValuesHash{$id.'.width'}    = $width;
       $ValuesHash{$id.'.xskip'}    = $xskip;
       $ValuesHash{$id.'.bar_width'} = $bar_width;
       $ValuesHash{$id.'.labels'} = join(',',@Labels);
       #
       &Apache::lonnet::appenv(%ValuesHash);
       return '<img src="/cgi-bin/graph.png?'.$identifier.'" border="1" />';
   }
   
   ############################################################
   ############################################################
   
   =pod
   
   =item DrawXYGraph
   
   Facilitates the plotting of data in an XY graph.
   Puts plot definition data into the users environment in order for 
   graph.png to plot it.  Returns an <img> tag for the plot.
   
 =item *  Inputs:
   
 get_student_view() : show a snapshot of what student was looking at  =over 4
   
 =item *  =item $Title: string, the title of the plot
   
 get_student_answers() : show a snapshot of how student was answering problem  =item $xlabel: string, text describing the X-axis of the plot
   
 =item *  =item $ylabel: string, text describing the Y-axis of the plot
   
 get_unprocessed_cgi() : get unparsed CGI parameters  =item $Max: scalar, the maximum Y value to use in the plot
   If $Max is < any data point, the graph will not be rendered.
   
 =item *  =item $colors: Array ref containing the hex color codes for the data to be 
   plotted in.  If undefined, default values will be used.
   
 cacheheader() : returns cache-controlling header code  =item $Xlabels: Array ref containing the labels to be used for the X-axis.
   
 =item *  =item $Ydata: Array ref containing Array refs.  
   Each of the contained arrays will be plotted as a seperate curve.
   
 nocache() : specifies header code to not have cache  =item %Values: hash indicating or overriding any default values which are 
   passed to graph.png.  
   Possible values are: width, xskip, x_ticks, x_tick_offset, among others.
   
 =item *  =back
   
 add_to_env($name,$value) : adds $name to the %ENV hash with value  Returns:
 $value, if $name already exists, the entry is converted to an array  
 reference and $value is added to the array.  An <img> tag which references graph.png and the appropriate identifying
   information for the plot.
   
   =cut
   
   ############################################################
   ############################################################
   sub DrawXYGraph {
       my ($Title,$xlabel,$ylabel,$Max,$colors,$Xlabels,$Ydata,%Values)=@_;
       #
       # Create the identifier for the graph
       my $identifier = &get_cgi_id();
       my $id = 'cgi.'.$identifier;
       #
       $Title  = '' if (! defined($Title));
       $xlabel = '' if (! defined($xlabel));
       $ylabel = '' if (! defined($ylabel));
       my %ValuesHash = 
           (
            $id.'.title'  => &Apache::lonnet::escape($Title),
            $id.'.xlabel' => &Apache::lonnet::escape($xlabel),
            $id.'.ylabel' => &Apache::lonnet::escape($ylabel),
            $id.'.y_max_value'=> $Max,
            $id.'.labels'     => join(',',@$Xlabels),
            $id.'.PlotType'   => 'XY',
            );
       #
       if (defined($colors) && ref($colors) eq 'ARRAY') {
           $ValuesHash{$id.'.Colors'}   = join(',',@{$colors});
       }
       #
       if (! ref($Ydata) || ref($Ydata) ne 'ARRAY') {
           return '';
       }
       my $NumSets=1;
       foreach my $array (@{$Ydata}){
           next if (! ref($array));
           $ValuesHash{$id.'.data.'.$NumSets++} = join(',',@$array);
       }
       $ValuesHash{$id.'.NumSets'} = $NumSets-1;
       #
       # Deal with other parameters
       while (my ($key,$value) = each(%Values)) {
           $ValuesHash{$id.'.'.$key} = $value;
       }
       #
       &Apache::lonnet::appenv(%ValuesHash);
       return '<img src="/cgi-bin/graph.png?'.$identifier.'" border="1" />';
   }
   
   ############################################################
   ############################################################
   
   =pod
   
   =item DrawXYYGraph
   
   Facilitates the plotting of data in an XY graph with two Y axes.
   Puts plot definition data into the users environment in order for 
   graph.png to plot it.  Returns an <img> tag for the plot.
   
   Inputs:
   
   =over 4
   
   =item $Title: string, the title of the plot
   
   =item $xlabel: string, text describing the X-axis of the plot
   
   =item $ylabel: string, text describing the Y-axis of the plot
   
   =item $colors: Array ref containing the hex color codes for the data to be 
   plotted in.  If undefined, default values will be used.
   
   =item $Xlabels: Array ref containing the labels to be used for the X-axis.
   
   =item $Ydata1: The first data set
   
   =item $Min1: The minimum value of the left Y-axis
   
   =item $Max1: The maximum value of the left Y-axis
   
   =item $Ydata2: The second data set
   
   =item $Min2: The minimum value of the right Y-axis
   
   =item $Max2: The maximum value of the left Y-axis
   
   =item %Values: hash indicating or overriding any default values which are 
   passed to graph.png.  
   Possible values are: width, xskip, x_ticks, x_tick_offset, among others.
   
   =back
   
   Returns:
   
   An <img> tag which references graph.png and the appropriate identifying
   information for the plot.
   
   =cut
   
   ############################################################
   ############################################################
   sub DrawXYYGraph {
       my ($Title,$xlabel,$ylabel,$colors,$Xlabels,$Ydata1,$Min1,$Max1,
                                           $Ydata2,$Min2,$Max2,%Values)=@_;
       #
       # Create the identifier for the graph
       my $identifier = &get_cgi_id();
       my $id = 'cgi.'.$identifier;
       #
       $Title  = '' if (! defined($Title));
       $xlabel = '' if (! defined($xlabel));
       $ylabel = '' if (! defined($ylabel));
       my %ValuesHash = 
           (
            $id.'.title'  => &Apache::lonnet::escape($Title),
            $id.'.xlabel' => &Apache::lonnet::escape($xlabel),
            $id.'.ylabel' => &Apache::lonnet::escape($ylabel),
            $id.'.labels' => join(',',@$Xlabels),
            $id.'.PlotType' => 'XY',
            $id.'.NumSets' => 2,
            $id.'.two_axes' => 1,
            $id.'.y1_max_value' => $Max1,
            $id.'.y1_min_value' => $Min1,
            $id.'.y2_max_value' => $Max2,
            $id.'.y2_min_value' => $Min2,
            );
       #
       if (defined($colors) && ref($colors) eq 'ARRAY') {
           $ValuesHash{$id.'.Colors'}   = join(',',@{$colors});
       }
       #
       if (! ref($Ydata1) || ref($Ydata1) ne 'ARRAY' ||
           ! ref($Ydata2) || ref($Ydata2) ne 'ARRAY'){
           return '';
       }
       my $NumSets=1;
       foreach my $array ($Ydata1,$Ydata2){
           next if (! ref($array));
           $ValuesHash{$id.'.data.'.$NumSets++} = join(',',@$array);
       }
       #
       # Deal with other parameters
       while (my ($key,$value) = each(%Values)) {
           $ValuesHash{$id.'.'.$key} = $value;
       }
       #
       &Apache::lonnet::appenv(%ValuesHash);
       return '<img src="/cgi-bin/graph.png?'.$identifier.'" border="1" />';
   }
   
   ############################################################
   ############################################################
   
   =pod
   
   =back 
   
   =head1 Statistics helper routines?  
   
   Bad place for them but what the hell.
   
   =over 4
   
   =item &chartlink
   
   Returns a link to the chart for a specific student.  
   
   Inputs:
   
   =over 4
   
   =item $linktext: The text of the link
   
   =item $sname: The students username
   
   =item $sdomain: The students domain
   
   =back
   
 =back  =back
   
 =cut  =cut
   
   ############################################################
   ############################################################
   sub chartlink {
       my ($linktext, $sname, $sdomain) = @_;
       my $link = '<a href="/adm/statistics?reportSelected=student_assessment'.
           '&SelectedStudent='.&Apache::lonnet::escape($sname.':'.$sdomain).
           '&chartoutputmode='.HTML::Entities::encode('html, with all links').
          '">'.$linktext.'</a>';
   }
   
   #######################################################
   #######################################################
   
   =pod
   
   =head1 Course Environment Routines
   
   =over 4
   
   =item &restore_course_settings 
   
   =item &store_course_settings
   
   Restores/Store indicated form parameters from the course environment.
   Will not overwrite existing values of the form parameters.
   
   Inputs: 
   a scalar describing the data (e.g. 'chart', 'problem_analysis')
   
   a hash ref describing the data to be stored.  For example:
      
   %Save_Parameters = ('Status' => 'scalar',
       'chartoutputmode' => 'scalar',
       'chartoutputdata' => 'scalar',
       'Section' => 'array',
       'StudentData' => 'array',
       'Maps' => 'array');
   
   Returns: both routines return nothing
   
   =cut
   
   #######################################################
   #######################################################
   sub store_course_settings {
       # save to the environment
       # appenv the same items, just to be safe
       my $courseid = $ENV{'request.course.id'};
       my $coursedom = $ENV{'course.'.$courseid.'.domain'};
       my ($prefix,$Settings) = @_;
       my %SaveHash;
       my %AppHash;
       while (my ($setting,$type) = each(%$Settings)) {
           my $basename = 'env.internal.'.$prefix.'.'.$setting;
           my $envname = 'course.'.$courseid.'.'.$basename;
           if (exists($ENV{'form.'.$setting})) {
               # Save this value away
               if ($type eq 'scalar' &&
                   (! exists($ENV{$envname}) || 
                    $ENV{$envname} ne $ENV{'form.'.$setting})) {
                   $SaveHash{$basename} = $ENV{'form.'.$setting};
                   $AppHash{$envname}   = $ENV{'form.'.$setting};
               } elsif ($type eq 'array') {
                   my $stored_form;
                   if (ref($ENV{'form.'.$setting})) {
                       $stored_form = join(',',
                                           map {
                                               &Apache::lonnet::escape($_);
                                           } sort(@{$ENV{'form.'.$setting}}));
                   } else {
                       $stored_form = 
                           &Apache::lonnet::escape($ENV{'form.'.$setting});
                   }
                   # Determine if the array contents are the same.
                   if ($stored_form ne $ENV{$envname}) {
                       $SaveHash{$basename} = $stored_form;
                       $AppHash{$envname}   = $stored_form;
                   }
               }
           }
       }
       my $put_result = &Apache::lonnet::put('environment',\%SaveHash,
                                             $coursedom,
                                             $ENV{'course.'.$courseid.'.num'});
       if ($put_result !~ /^(ok|delayed)/) {
           &Apache::lonnet::logthis('unable to save form parameters, '.
                                    'got error:'.$put_result);
       }
       # Make sure these settings stick around in this session, too
       &Apache::lonnet::appenv(%AppHash);
       return;
   }
   
   sub restore_course_settings {
       my $courseid = $ENV{'request.course.id'};
       my ($prefix,$Settings) = @_;
       while (my ($setting,$type) = each(%$Settings)) {
           next if (exists($ENV{'form.'.$setting}));
           my $envname = 'course.'.$courseid.'.env.internal.'.$prefix.
               '.'.$setting;
           if (exists($ENV{$envname})) {
               if ($type eq 'scalar') {
                   $ENV{'form.'.$setting} = $ENV{$envname};
               } elsif ($type eq 'array') {
                   $ENV{'form.'.$setting} = [ 
                                              map { 
                                                  &Apache::lonnet::unescape($_); 
                                              } split(',',$ENV{$envname})
                                              ];
               }
           }
       }
   }
   
   ############################################################
   ############################################################
   
   sub propath {
       my ($udom,$uname)=@_;
       $udom=~s/\W//g;
       $uname=~s/\W//g;
       my $subdir=$uname.'__';
       $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
       my $proname="$Apache::lonnet::perlvar{'lonUsersDir'}/$udom/$subdir/$uname";
       return $proname;
   } 
   
   sub icon {
       my ($file)=@_;
       my $curfext = (split(/\./,$file))[-1];
       my $iconname=$Apache::lonnet::perlvar{'lonIconsURL'}.'/unknown.gif';
       my $embstyle = &Apache::loncommon::fileembstyle($curfext);
       if (!(!defined($embstyle) || $embstyle eq 'unk' || $embstyle eq 'hdn')) {
    if (-e  $Apache::lonnet::perlvar{'lonDocRoot'}.'/'.
             $Apache::lonnet::perlvar{'lonIconsURL'}.'/'.
               $curfext.".gif") {
       $iconname=$Apache::lonnet::perlvar{'lonIconsURL'}.'/'.
    $curfext.".gif";
    }
       }
       return $iconname;
   } 
   
   =pod
   
   =back
   
   =cut
   
   1;
   __END__;
   

Removed from v.1.25  
changed lines
  Added in v.1.169


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