--- loncom/interface/lonfeedback.pm	2012/03/07 00:02:10	1.337
+++ loncom/interface/lonfeedback.pm	2012/03/09 15:02:31	1.338
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Feedback
 #
-# $Id: lonfeedback.pm,v 1.337 2012/03/07 00:02:10 raeburn Exp $
+# $Id: lonfeedback.pm,v 1.338 2012/03/09 15:02:31 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -955,6 +955,9 @@ sub build_posting_display {
     my $thisuser=$env{'user.name'}.':'.$env{'user.domain'};
 # Array with likes to figure out averages, etc.
     my @theselikes=();
+# Hashes containing likes and unlikes for this user.
+    my %userlikes=();
+    my %userunlikes=();
 # Is the user allowed to see the real name behind anonymous postings?
     my $see_anonymous = 
 	&Apache::lonnet::allowed('rin',$env{'request.course.id'}.($env{'request.course.sec'}?'/'.$env{'request.course.sec'}:''));
@@ -994,10 +997,23 @@ sub build_posting_display {
             next if ($contrib{$idx.':deleted'});
             next if ($contrib{$idx.':hidden'});
             unless ((($hiddens{$idx}) && (!$seeid)) || ($deletions{$idx}) || (!$contrib{$idx.':message'})) {
-                push(@theselikes,$likes{$symb.':'.$idx.':likes'});
+                if ($likes{$symb.':'.$idx.':likes'} ne '') {
+                    push(@theselikes,$likes{$symb.':'.$idx.':likes'});
+                    if (ref($likes{$symb.':'.$idx.':likers'}) eq 'HASH') {
+                        if (exists($likes{$symb.':'.$idx.':likers'}{$thisuser})) {
+                            $userlikes{$idx} = 1;
+                        }
+                    }
+                    if (ref($likes{$symb.':'.$idx.':unlikers'}) eq 'HASH') {
+                        if (exists($likes{$symb.':'.$idx.':unlikers'}{$thisuser})) {
+                            $userunlikes{$idx} = 1;
+                        }
+                    }
+                }
             }
         }
-# Figure out average likes and standard deviation if there are enough discussions to warrant that
+# Figure out average likes and standard deviation if there are enough 
+# discussions to warrant that
         my $ave=0;
         my $stddev=10000;
         if ($#theselikes>1) {
@@ -1021,7 +1037,7 @@ sub build_posting_display {
         my $twominus=$ave-2.*$stddev;
 #
 # This is now the real loop. Go through all entries, pick up what we need
-# 
+#
 	for (my $id=1;$id<=$contrib{'version'};$id++) {
 	    my $idx=$id;
             next if ($contrib{$idx.':deleted'});
@@ -1368,15 +1384,15 @@ sub build_posting_display {
                                     $message.
                                     '</div></blockquote>';
 # Put in the like and unlike buttons
-                            unless ($likes{$symb.':'.$idx.':likers'}=~/\,\Q$thisuser\E\,/) {
-                                $$discussionitems[$idx].='&nbsp;'.&discussion_link($symb,'<img border="0" src="/res/adm/pages/thumbsup.png" alt="'.&mt('Like').'" />','like',$idx,$$newpostsflag,$prevread,&group_args($group),&mt("Like this posting"));
-                            } else {
+                            if ($userlikes{$idx}) {
                                 $$discussionitems[$idx].='<img border="0" src="/res/adm/pages/thumbsup_gray.png" alt="'.&mt('You like this posting').'" />';
-                            }
-                            unless ($likes{$symb.':'.$idx.':unlikers'}=~/\,\Q$thisuser\E\,/) {
-                                $$discussionitems[$idx].='&nbsp;'.&discussion_link($symb,'<img border="0" src="/res/adm/pages/thumbsdown.png" alt="'.&mt('Unlike').'" />','unlike',$idx,$$newpostsflag,$prevread,&group_args($group),&mt("Unlike this posting"));
                             } else {
+                                $$discussionitems[$idx].='&nbsp;'.&discussion_link($symb,'<img border="0" src="/res/adm/pages/thumbsup.png" alt="'.&mt('Like').'" />','like',$idx,$$newpostsflag,$prevread,&group_args($group),&mt("Like this posting"));
+                            }
+                            if ($userunlikes{$idx}) {
                                 $$discussionitems[$idx].='<img border="0" src="/res/adm/pages/thumbsdown_gray.png" alt="'.&mt('You unlike this posting').'" />';
+                            } else {
+                                $$discussionitems[$idx].='&nbsp;'.&discussion_link($symb,'<img border="0" src="/res/adm/pages/thumbsdown.png" alt="'.&mt('Unlike').'" />','unlike',$idx,$$newpostsflag,$prevread,&group_args($group),&mt("Unlike this posting"));
                             }
                             my $thislikes=$likes{$symb.':'.$idx.':likes'};
                             if ($thislikes>0) {
@@ -4019,44 +4035,62 @@ ENDREDIR
                                         $env{'course.'.$env{'request.course.id'}.'.domain'},
                                         $env{'course.'.$env{'request.course.id'}.'.num'},
                                         '^'.$prefix);
-# Get all who like or unlike this
-      my $currentlikers=$contrib{$prefix.'likers'};
-      my $currentunlikers=$contrib{$prefix.'unlikers'};
+
+# Get current like or unlike status for the $idx for this user.
+      my $thisuser=$env{'user.name'}.':'.$env{'user.domain'};
+      my ($userlikes,$userunlikes);
+      if (ref($contrib{$prefix.'likers'}) eq 'HASH') {
+          if (exists($contrib{$prefix.'likers'}{$thisuser})) {
+              $userlikes = 1;
+          }
+      }
+      if (ref($contrib{$prefix.'unlikers'}) eq 'HASH') {
+          if (exists($contrib{$prefix.'unlikers'}{$thisuser})) {
+              $userunlikes = 1;
+          }
+      }
 # Get the current "likes" count
       my $likes=$contrib{$prefix.'likes'};
 # Find out if they already voted
-# Users cannot like a post twice, or unlike it twice. They can change their mind, though
+# Users cannot like a post twice, or unlike it twice.
+# They can change their mind, though.
       my $alreadyflag=0;
       my $thisuser=$env{'user.name'}.':'.$env{'user.domain'};
       if ($env{'form.like'}) {
-          if ($currentlikers=~/\,\Q$thisuser\E\,/) {
+          if ($userlikes) {
               $alreadyflag=1;
+          } elsif ($userunlikes) {
+              delete($contrib{$prefix.'unlikers'}{$thisuser});
+              $likes++;
           } else {
-              if ($currentunlikers=~/\,\Q$thisuser\E\,/) {
-                  $currentunlikers=~s/\,\Q$thisuser\E\,//g;
+              if (ref($contrib{$prefix.'likers'}) eq 'HASH') {
+                  $contrib{$prefix.'likers'}{$thisuser} = 1;
               } else {
-                  $currentlikers.=','.$thisuser.',';
+                  $contrib{$prefix.'likers'} = {$thisuser => 1};
               }
               $likes++;
-          } 
+          }
       } else {
-          if ($currentunlikers=~/\,\Q$thisuser\E\,/) {
+          if ($userunlikes) {
               $alreadyflag=1;
+          } elsif ($userlikes) {
+              delete($contrib{$prefix.'likers'}{$thisuser});
+              $likes--;
           } else {
-              if ($currentlikers=~/\,\Q$thisuser\E\,/) {
-                  $currentlikers=~s/\,\Q$thisuser\E\,//g;
+              if (ref($contrib{$prefix.'unlikers'}) eq 'HASH') {
+                  $contrib{$prefix.'unlikers'}{$thisuser} = 1;
               } else {
-                  $currentunlikers.=','.$thisuser.',';
+                  $contrib{$prefix.'unlikers'} = {$thisuser => 1};
               }
               $likes--;
-          } 
+          }
       }
       my $result;
 # $alreadyflag would be 1 if they tried to double-like or double-unlike
       unless ($alreadyflag) {
           my %newhash=($prefix.'likes'    => $likes,
-                       $prefix.'likers'   => $currentlikers,
-                       $prefix.'unlikers' => $currentunlikers);
+                       $prefix.'likers'   => $contrib{$prefix.'likers'},
+                       $prefix.'unlikers' => $contrib{$prefix.'unlikers'});
 # Store data in db-file "disclikes"
           if (&Apache::lonnet::put('disclikes',
                                    \%newhash,