--- loncom/interface/loncommon.pm	2002/07/09 17:15:58	1.45
+++ loncom/interface/loncommon.pm	2002/08/01 16:48:21	1.48
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # a pile of common routines
 #
-# $Id: loncommon.pm,v 1.45 2002/07/09 17:15:58 matthew Exp $
+# $Id: loncommon.pm,v 1.48 2002/08/01 16:48:21 bowersj2 Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -79,26 +79,48 @@ package Apache::loncommon;
 
 use strict;
 use Apache::lonnet();
+use GDBM_File;
 use POSIX qw(strftime);
 use Apache::Constants qw(:common);
 use Apache::lonmsg();
 my $readit;
 
+=pod 
+
+=item Global Variables
+
+=over 4
+
+=cut
 # ----------------------------------------------- Filetypes/Languages/Copyright
 my %language;
 my %cprtag;
 my %fe; my %fd;
 my %category_extensions;
 
-# -------------------------------------------------------------- Thesaurus data
-my @therelated;
-my @theword;
-my @thecount;
-my %theindex;
-my $thetotalcount;
-my $thefuzzy=2;
-my $thethreshold=0.1/$thefuzzy;
-my $theavecount;
+# ---------------------------------------------- Thesaurus variables
+
+=pod
+
+=item %Keywords  
+
+A hash used by &keyword to determine if a word is considered a keyword.
+
+=item $thesaurus_db_file
+
+Scalar containing the full path to the thesaurus database.                 
+
+=cut
+
+my %Keywords;
+my $thesaurus_db_file;
+
+
+=pod
+
+=back
+
+=cut
 
 # ----------------------------------------------------------------------- BEGIN
 
@@ -114,7 +136,9 @@ thesaurus.tab, and filecategories.tab.
 # ----------------------------------------------------------------------- BEGIN
 
 BEGIN {
-
+    # Variable initialization
+    $thesaurus_db_file = $Apache::lonnet::perlvar{'lonTabDir'}."/thesaurus.db";
+    #
     unless ($readit) {
 # ------------------------------------------------------------------- languages
     {
@@ -171,26 +195,10 @@ BEGIN {
 	    }
 	}
     }
-# -------------------------------------------------------------- Thesaurus data
-    {
-	my $fh=Apache::File->new($Apache::lonnet::perlvar{'lonTabDir'}.
-	       '/thesaurus.dat');
-	if ($fh) {
-            while (<$fh>) {
-               my ($tword,$tindex,$tcount,$trelated)=split(/\@/,$_);
-               $theindex{$tword}=$tindex;
-               $theword[$tindex]=$tword;
-               $thecount[$tindex]=$tcount;
-               $thetotalcount+=$tcount;
-               $therelated[$tindex]=$trelated;
-	   }
-        }
-        $theavecount=$thetotalcount/$#thecount;
-    }
     &Apache::lonnet::logthis(
-              "<font color=yellow>INFO: Read file types and thesaurus</font>");
+              "<font color=yellow>INFO: Read file types</font>");
     $readit=1;
-}
+    }  # end of unless($readit) 
     
 }
 # ============================================================= END BEGIN BLOCK
@@ -431,10 +439,12 @@ END
 
 =pod
 
-=item help_open_topic($topic, $stayOnPage, $width, $height)
+=item help_open_topic($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.
@@ -442,33 +452,37 @@ $width and $height are optional numerica
 =cut
 
 sub help_open_topic {
-    my ($topic, $stayOnPage, $width, $height) = @_;
+    my ($topic, $text, $stayOnPage, $width, $height) = @_;
+    $text = "" if (not defined $text);
     $stayOnPage = 0 if (not defined $stayOnPage);
     $width = 350 if (not defined $width);
     $height = 400 if (not defined $height);
     my $filename = $topic;
     $filename =~ s/ /_/g;
 
-    my $template;
+    my $template = "";
+    my $link;
 
     if (!$stayOnPage)
     {
-        $template = <<"ENDTEMPLATE";
-<a href="javascript:void(open('/adm/help/${filename}.hlp', 'Help for $topic', 'menubar=0,s
-crollbars=1,width=$width,height=$height'))"><image
-  src="/adm/help/gif/smallHelp.gif"
-  border="0" alt="(Help: $topic)"></a>
-ENDTEMPLATE
+	$link = "javascript:void(open('/adm/help/${filename}.hlp', 'Help_for_$topic', 'menubar=0,toolbar=1,scrollbars=1,width=$width,height=$height'))";
     }
     else
     {
-        $template = <<"ENDTEMPLATE";
-<a href="/adm/help/${filename}.hlp"><image
-  src="/adm/help/gif/smallHelp.gif"
-  border="0" alt="(Help: $topic)"></a>
-ENDTEMPLATE
+	$link = "/adm/help/${filename}.hlp";
     }
 
+    # Add the text
+    if ($text ne "")
+    {
+	$template .= "<a href=\"$link\">$text</a> ";
+    }
+
+    # Add the graphic
+    $template .= <<"ENDTEMPLATE";
+<a href="$link"><image src="/adm/help/gif/smallHelp.gif" border="0" alt="(Help: $topic)"></a>
+ENDTEMPLATE
+
     return $template;
 
 }
@@ -490,8 +504,6 @@ sub csv_translate {
 }
 
 ###############################################################
-
-###############################################################
 ##        Home server <option> list generating code          ##
 ###############################################################
 #-------------------------------------------
@@ -805,66 +817,166 @@ END
 ##   End Authentication changing form generation functions   ##
 ###############################################################
 
+###############################################################
+##                Thesaurus Functions                        ##
+###############################################################
 
+=pod
 
-# ---------------------------------------------------------- Is this a keyword?
+=item initialize_keywords
 
-sub keyword {
-    my $newword=shift;
-    $newword=~s/\W//g;
-    $newword=~tr/A-Z/a-z/;
-    my $tindex=$theindex{$newword};
-    if ($tindex) {
-        if ($thecount[$tindex]>$theavecount) {
-           return 1;
-        }
+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{$_}));
     }
-    return 0;
+    return 1;
+}
+
+###################################################
+
+=pod
+
+=item keyword($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});
 }
+
+###################################################
+#         Old code, to be removed soon            #
+###################################################
 # -------------------------------------------------------- Return related words
+#sub related {
+#    my $newword=shift;
+#    $newword=~s/\W//g;
+#    $newword=~tr/A-Z/a-z/;
+#    my $tindex=$theindex{$newword};
+#    if ($tindex) {
+#        my %found=();
+#        foreach (split(/\,/,$therelated[$tindex])) {
+## - Related word found
+#            my ($ridx,$rcount)=split(/\:/,$_);
+## - Direct relation index
+#            my $directrel=$rcount/$thecount[$tindex];
+#            if ($directrel>$thethreshold) {
+#               foreach (split(/\,/,$therelated[$ridx])) {
+#                  my ($rridx,$rrcount)=split(/\:/,$_);
+#                  if ($rridx==$tindex) {
+## - Determine reverse relation index
+#                     my $revrel=$rrcount/$thecount[$ridx];
+## - Calculate full index
+#                     $found{$ridx}=$directrel*$revrel;
+#                     if ($found{$ridx}>$thethreshold) {
+#                        foreach (split(/\,/,$therelated[$ridx])) {
+#                            my ($rrridx,$rrrcount)=split(/\:/,$_);
+#                            unless ($found{$rrridx}) {
+#                               my $revrevrel=$rrrcount/$thecount[$ridx];
+#                               if (
+#                          $directrel*$revrel*$revrevrel>$thethreshold
+#                               ) {
+#                                  $found{$rrridx}=
+#                                       $directrel*$revrel*$revrevrel;
+#                               }
+#                            }
+#                        }
+#                     }
+#                  }
+#               }
+#            }
+#        }
+#    }
+#    return ();
+#}
 
-sub related {
-    my $newword=shift;
-    $newword=~s/\W//g;
-    $newword=~tr/A-Z/a-z/;
-    my $tindex=$theindex{$newword};
-    if ($tindex) {
-        my %found=();
-        foreach (split(/\,/,$therelated[$tindex])) {
-# - Related word found
-            my ($ridx,$rcount)=split(/\:/,$_);
-# - Direct relation index
-            my $directrel=$rcount/$thecount[$tindex];
-            if ($directrel>$thethreshold) {
-               foreach (split(/\,/,$therelated[$ridx])) {
-                  my ($rridx,$rrcount)=split(/\:/,$_);
-                  if ($rridx==$tindex) {
-# - Determine reverse relation index
-                     my $revrel=$rrcount/$thecount[$ridx];
-# - Calculate full index
-                     $found{$ridx}=$directrel*$revrel;
-                     if ($found{$ridx}>$thethreshold) {
-                        foreach (split(/\,/,$therelated[$ridx])) {
-                            my ($rrridx,$rrrcount)=split(/\:/,$_);
-                            unless ($found{$rrridx}) {
-                               my $revrevrel=$rrrcount/$thecount[$ridx];
-                               if (
-                          $directrel*$revrel*$revrevrel>$thethreshold
-                               ) {
-                                  $found{$rrridx}=
-                                       $directrel*$revrel*$revrevrel;
-                               }
-                            }
-                        }
-                     }
-                  }
-               }
-            }
+###############################################################
+
+=pod 
+
+=item get_related_words
+
+Look up a word in the thesaurus.  Takes a scalar arguement 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];
         }
     }
-    return ();
+    untie %thesaurus_db;
+    return @Words;
 }
 
+###############################################################
+##              End Thesaurus Functions                      ##
+###############################################################
+
 # ---------------------------------------------------------------- Language IDs
 sub languageids {
     return sort(keys(%language));