--- loncom/lonnet/perl/lonnet.pm	2005/11/21 15:41:29	1.681
+++ loncom/lonnet/perl/lonnet.pm	2005/11/22 02:24:55	1.684
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.681 2005/11/21 15:41:29 raeburn Exp $
+# $Id: lonnet.pm,v 1.684 2005/11/22 02:24:55 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -3703,24 +3703,8 @@ sub auto_instcode_format {
 # ------------------------------------------------------- Course Group routines
 
 sub get_coursegroups {
-    my ($cdom,$cnum,$curr_groups,$group) = @_;
-    my $numgroups = 0;
-    %{$curr_groups} = &dump('coursegroups',$cdom,$cnum,$group);
-    my ($tmp)=keys(%{$curr_groups});
-    if ($tmp eq 'error: 2 tie(GDBM) Failed while attempting dump') {
-        my %emptyhash = ();
-        if (&put('coursegroups',\%emptyhash,$cdom,$cnum) eq 'ok') {
-            %{$curr_groups} = &dump('coursegroups',$cdom,$cnum,$group);
-            $tmp=keys(%{$curr_groups});
-        }
-    }
-    if ($tmp=~/^error:/) {
-        &logthis('Error retrieving groups: '.$tmp.' in '.$cnum.':'.$cdom);
-    } else {
-        my @groups = keys(%{$curr_groups});
-        $numgroups = @groups;
-    }
-    return $numgroups;
+    my ($cdom,$cnum,$group) = @_;
+    return(&dump('coursegroups',$cdom,$cnum,$group));
 }
 
 sub modify_coursegroup {
@@ -3734,6 +3718,10 @@ sub modify_group_roles {
     my $role = 'gr/'.&escape($userprivs);
     my ($uname,$udom) = split(/:/,$user);
     my $result = &assignrole($udom,$uname,$url,$role,$end,$start);
+    if ($result eq 'ok') {
+        &devalidate_getgroups_cache($udom,$uname,$cdom,$cnum);
+    }
+
     return $result;
 }
 
@@ -3743,6 +3731,66 @@ sub modify_coursegroup_membership {
     return $result;
 }
 
+sub get_active_groups {
+    my ($udom,$uname,$cdom,$cnum) = @_;
+    my $now = time;
+    my %groups = ();
+    foreach my $key (keys(%env)) {
+        if ($key =~ m-user\.role\.gr\./([^/]+)/([^/]+)/(\w+)$-) {
+            my ($start,$end) = split(/\./,$env{$key});
+            if (($end!=0) && ($end<$now)) { next; }
+            if (($start!=0) && ($start>$now)) { next; }
+            if ($1 eq $cdom && $2 eq $cnum) {
+                $groups{$3} = $env{$key} ;
+            }
+        }
+    }
+    return %groups;
+}
+
+sub get_group_membership {
+    my ($cdom,$cnum,$group) = @_;
+    return(&dump('groupmembership',$cdom,$cnum,$group));
+}
+
+sub get_users_groups {
+    my ($udom,$uname,$courseid) = @_;
+    my $cachetime=1800;
+    $courseid=~s/\_/\//g;
+    $courseid=~s/^(\w)/\/$1/;
+
+    my $hashid="$udom:$uname:$courseid";
+    my ($result,$cached)=&is_cached_new('getgroups',$hashid);
+    if (defined($cached)) { return $result; }
+
+    my %roleshash = &dump('roles',$udom,$uname,$courseid);
+    my ($tmp) = keys(%roleshash);
+    if ($tmp=~/^error:/) {
+        &logthis('Error retrieving roles: '.$tmp.' for '.$uname.':'.$udom);
+        return '';
+    } else {
+        my $grouplist;
+        foreach my $key (keys %roleshash) {
+            if ($key =~ /^\Q$courseid\E\/(\w+)\_gr$/) {
+                unless ($roleshash{$key} =~ /_1_1$/) {   # deleted membership
+                    $grouplist .= $1.':';
+                }
+            }
+        }
+        $grouplist =~ s/:$//;
+        return &do_cache_new('getgroups',$hashid,$grouplist,$cachetime);
+    }
+}
+
+sub devalidate_getgroups_cache {
+    my ($udom,$uname,$cdom,$cnum)=@_;
+    my $courseid = $cdom.'_'.$cnum;
+    $courseid=~s/\_/\//g;
+    $courseid=~s/^(\w)/\/$1/;
+    my $hashid="$udom:$uname:$courseid";
+    &devalidate_cache_new('getgroups',$hashid);
+}
+
 # ------------------------------------------------------------------ Plain Text
 
 sub plaintext {
@@ -4757,7 +4805,8 @@ sub EXT {
         return $env{'course.'.$courseid.'.'.$spacequalifierrest};
     } elsif ($realm eq 'resource') {
 
-	my $section;
+	my ($section,$group);
+        my @groups = ();
 	if (defined($courseid) && $courseid eq $env{'request.course.id'}) {
 	    if (!$symbparm) { $symbparm=&symbread(); }
 	}
@@ -4777,14 +4826,29 @@ sub EXT {
 	    if (($env{'user.name'} eq $uname) &&
 		($env{'user.domain'} eq $udom)) {
 		$section=$env{'request.course.sec'};
+                @groups=split(/:/,$env{'request.course.groups'});
+                if (@groups > 0) {
+                    @groups = sort(@groups);
+                    $group = $groups[0];
+                }
 	    } else {
 		if (! defined($usection)) {
 		    $section=&getsection($udom,$uname,$courseid);
 		} else {
 		    $section = $usection;
 		}
+                my $grouplist = &get_users_groups($udom,$uname,$courseid);
+                if ($grouplist) {
+                    @groups = split(/:/,$grouplist);
+                    @groups = sort(@groups);
+                    $group = $groups[0];
+                }
 	    }
 
+            my $grplevel=$courseid.'.['.$group.'].'.$spacequalifierrest;
+            my $grplevelr=$courseid.'.['.$group.'].'.$symbparm;
+            my $grplevelm=$courseid.'.['.$group.'].'.$mapparm;
+
 	    my $seclevel=$courseid.'.['.$section.'].'.$spacequalifierrest;
 	    my $seclevelr=$courseid.'.['.$section.'].'.$symbparm;
 	    my $seclevelm=$courseid.'.['.$section.'].'.$mapparm;
@@ -4802,8 +4866,17 @@ sub EXT {
 	    if (defined($userreply)) { return $userreply; }
 
 # ------------------------------------------------ second, check some of course
+            my $coursereply;
+            if (defined($group)) {
+                $coursereply = &resdata($env{'course.'.$courseid.'.num'},
+                                     $env{'course.'.$courseid.'.domain'},
+                                     'course',
+                                     ($grplevelr,$grplevelm,$grplevel,
+                                      $courselevelr));
+                if (defined($coursereply)) { return $coursereply; }
+            }
 
-	    my $coursereply=&resdata($env{'course.'.$courseid.'.num'},
+	    $coursereply=&resdata($env{'course.'.$courseid.'.num'},
 				     $env{'course.'.$courseid.'.domain'},
 				     'course',
 				     ($seclevelr,$seclevelm,$seclevel,