--- loncom/interface/lonfeedback.pm	2012/01/05 21:18:49	1.322
+++ loncom/interface/lonfeedback.pm	2012/01/06 18:17:44	1.324
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Feedback
 #
-# $Id: lonfeedback.pm,v 1.322 2012/01/05 21:18:49 www Exp $
+# $Id: lonfeedback.pm,v 1.324 2012/01/06 18:17:44 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -931,21 +931,26 @@ sub build_posting_display {
     my $skip_group_check = 0;
     my $symb=&Apache::lonenc::check_decrypt($ressymb);
     my $escsymb=&escape($ressymb);
+# These are the discussion contributions
     my %contrib=&Apache::lonnet::restore($symb,$env{'request.course.id'},
 			  $env{'course.'.$env{'request.course.id'}.'.domain'},
 			  $env{'course.'.$env{'request.course.id'}.'.num'});
+# And these are the likes/unlikes
     my %likes=&Apache::lonnet::dump('disclikes',
                           $env{'course.'.$env{'request.course.id'}.'.domain'},
                           $env{'course.'.$env{'request.course.id'}.'.num'},
                           '^'.$symb.':');
     my $thisuser=$env{'user.name'}.':'.$env{'user.domain'};
-
+# Array with likes to figure out averages, etc.
+    my @theselikes=();
+# 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'}:''));
 
     if ((@{$grouppick} == 0) || (grep(/^all$/,@{$grouppick}))) {
         $skip_group_check = 1;
     }
+# Deletions and hiddens are just lists. Split them up into a hash for quicker lookup
     my (%deletions,%hiddens);
     if ($contrib{'deleted'}) {
        my $deleted = $contrib{'deleted'};
@@ -959,6 +964,7 @@ sub build_posting_display {
        $hidden =~ s/\.$//;
        %hiddens = map { $_ => 1 } (split(/\.\./,$hidden));
     }
+# Versions if store/restore are used to actually store the messages. 
     if ($contrib{'version'}) {
         my $oldest = $contrib{'1:timestamp'};
         if ($prevread eq '0') {
@@ -974,6 +980,8 @@ sub build_posting_display {
 	    my $idx=$id;
             next if ($contrib{$idx.':deleted'});
             next if ($contrib{$idx.':hidden'});
+# If we get here, we are actually going to display the message - we don't know where and we don't know if we display
+# previous edits, but it counts as one entry
             my $posttime = $contrib{$idx.':timestamp'};
             if ($prevread <= $posttime) {
                 $$newpostsflag = 1;
@@ -1107,6 +1115,13 @@ sub build_posting_display {
                                 unless ($likes{$symb.':'.$idx.':unlikers'}=~/\,\Q$thisuser\E\,/) {
                                     $sender.='&nbsp;'.&discussion_link($symb,&mt('Unlike'),'unlike',$idx,$$newpostsflag,$prevread,&group_args($group));
                                 }
+                                my $thislikes=$likes{$symb.':'.$idx.':likes'};
+                                push(@theselikes,$thislikes);
+                                if ($thislikes>0) { 
+                                    $sender.='&nbsp;('.&mt("[_1] likes",$thislikes).')';
+                                } elsif ($thislikes<0) {
+                                    $sender.='&nbsp;('.&mt("[_1] unlikes",abs($thislikes)).')';
+                                }
                                 if (&editing_allowed($escsymb.':::'.$idx,$group)) {
                                     if (($env{'user.domain'} eq $contrib{$idx.':senderdomain'}) && ($env{'user.name'} eq $contrib{$idx.':sendername'})) {
                                         $sender.=' '.
@@ -1309,12 +1324,34 @@ sub build_posting_display {
                                     $$discussionitems[$idx] .= '<b>'.$version.'.</b> - '.&Apache::lonlocal::locallocaltime($postversions[$i]).'  ';
                                 }
                             }
+# end of unless ($$notshown ...)
                         }
+# end of if ($message) ...
                     }
+# end of the else-branch of target being export
                 }
+# end of unless hidden or deleted
             }
+# end of the loop over all discussion entries
 	}
+# Figure out average likes and standard deviation if there are enough discussions to warrant that
+        if ($#theselikes>1) {
+            my $sum=0;
+            my $num=$#theselikes+1;
+            foreach my $thislike (@theselikes) {
+                $sum.=$thislike;
+            }
+            my $ave=$sum/$num;
+            my $sumsq=0;
+            foreach my $thislike (@theselikes) {
+                $sumsq+=($thislike-$ave)*($thislike-$ave);
+            }
+            my $stddev=sqrt($sumsq/$num);
+#            &Apache::lonnet::logthis(join(',',@theselikes)." Ave $ave StdDev $stddev");
+        }
+# end of "if there actually are any discussion
     }
+# end of subroutine "build_posting_display" 
 }
 
 sub filter_regexp {
@@ -3851,6 +3888,11 @@ ENDREDIR
       my $entry=$env{'form.like'}?$env{'form.like'}:$env{'form.unlike'};
       my ($symb,$idx)=split(/\:\:\:/,$entry);
       ($symb,my $feedurl)=&get_feedurl_and_clean_symb($symb);
+#
+# Likes and unlikes are in db-file "disclikes" of the course
+# The prefix is the $symb to identify the resource discussion,
+# and the $idx to identify the entry
+#
       my $prefix=$symb.':'.$idx.':';
       my %contrib=&Apache::lonnet::dump('disclikes',
                                         $env{'course.'.$env{'request.course.id'}.'.domain'},
@@ -3859,8 +3901,10 @@ ENDREDIR
 # Get all who like or unlike this
       my $currentlikers=$contrib{$prefix.'likers'};
       my $currentunlikers=$contrib{$prefix.'unlikers'};
+# 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
       my $alreadyflag=0;
       my $thisuser=$env{'user.name'}.':'.$env{'user.domain'};
       if ($env{'form.like'}) {
@@ -3868,7 +3912,7 @@ ENDREDIR
               $alreadyflag=1;
           } else {
               if ($currentunlikers=~/\,\Q$thisuser\E\,/) {
-                  $currentunlikers=~s/\,\Q$thisuser\E\,//;
+                  $currentunlikers=~s/\,\Q$thisuser\E\,//g;
               } else {
                   $currentlikers.=','.$thisuser.',';
               }
@@ -3879,7 +3923,7 @@ ENDREDIR
               $alreadyflag=1;
           } else {
               if ($currentlikers=~/\,\Q$thisuser\E\,/) {
-                  $currentlikers=~s/\,\Q$thisuser\E\,//;
+                  $currentlikers=~s/\,\Q$thisuser\E\,//g;
               } else {
                   $currentunlikers.=','.$thisuser.',';
               }
@@ -3887,14 +3931,17 @@ ENDREDIR
           } 
       }
       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);
+# Store data in db-file "disclikes"
           if (&Apache::lonnet::put('disclikes',
                                    \%newhash,
                                    $env{'course.'.$env{'request.course.id'}.'.domain'},
                                    $env{'course.'.$env{'request.course.id'}.'.num'}) eq 'ok') {
+# Also store with the person who posted the liked/unliked entry
               if ($env{'form.like'}) {
                   &storediscussionlikes(1,$contrib{$idx.':sendername'},$contrib{$idx.':senderdomain'});
                   $result=&mt("Registered 'Like'");
@@ -3903,6 +3950,7 @@ ENDREDIR
                   $result=&mt("Registered 'Unlike'");
               }
           } else {
+# Oops, something went wrong
               $result=&mt("Failed to register vote");
           }
       }