--- loncom/interface/lonnavmaps.pm	2004/09/29 19:13:20	1.298
+++ loncom/interface/lonnavmaps.pm	2004/10/07 22:12:47	1.300
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Navigate Maps Handler
 #
-# $Id: lonnavmaps.pm,v 1.298 2004/09/29 19:13:20 albertel Exp $
+# $Id: lonnavmaps.pm,v 1.300 2004/10/07 22:12:47 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -35,7 +35,7 @@ use Apache::loncommon();
 use Apache::lonmenu();
 use Apache::lonlocal;
 use POSIX qw (floor strftime);
-use Data::Dumper; # for debugging, not always used
+use Data::Dumper; # for debugging, not always 
 
 # symbolic constants
 sub SYMB { return 1; }
@@ -410,7 +410,6 @@ ENDSUBM
                        'caller' => 'navmapsdisplay',
                        'linkitems' => \%toplinkitems};
     my $render = render($renderArgs);
-    $navmap->untieHashes();
 
     # If no resources were printed, print a reassuring message so the
     # user knows there was no error.
@@ -1585,7 +1584,6 @@ END
 	    }
 	    if ($totdisc > 0) {
 		$haveDisc =~ s/:$//;
-		my $navurl = $ENV{'QUERY_STRING'};
 		$result .= (<<END);
 	<input type="hidden" name="navmaps" value="$haveDisc" />
     </form>
@@ -1941,8 +1939,6 @@ if (location.href.indexOf('#curloc')==-1
         $r->rflush();
     }
         
-    if ($mustCloseNavMap) { $navmap->untieHashes(); } 
-
     return $result;
 }
 
@@ -2043,10 +2039,6 @@ successful, or B<undef> if not.
 
 =back
 
-When you are done with the $navmap object, you I<must> call 
-$navmap->untieHashes(), or you'll prevent the current user from using that 
-course until the web server is restarted. (!)
-
 =head2 Methods
 
 =over 4
@@ -2263,13 +2255,6 @@ sub getIterator {
     return $iterator;
 }
 
-# unties the hash when done
-sub untieHashes {
-    my $self = shift;
-    untie %{$self->{NAV_HASH}};
-    untie %{$self->{PARM_HASH}};
-}
-
 # Private method: Does the given resource (as a symb string) have
 # current discussion? Returns 0 if chat/mail data not extracted.
 sub hasDiscussion {
@@ -2650,7 +2635,7 @@ sub hasResource {
 1;
 
 package Apache::lonnavmaps::iterator;
-
+use WeakRef;
 =pod
 
 =back
@@ -2790,7 +2775,7 @@ sub new {
     my $class = ref($proto) || $proto;
     my $self = {};
 
-    $self->{NAV_MAP} = shift;
+    weaken($self->{NAV_MAP} = shift);
     return undef unless ($self->{NAV_MAP});
 
     # Handle the parameters
@@ -3126,7 +3111,7 @@ sub populateStack {
 1;
 
 package Apache::lonnavmaps::DFSiterator;
-
+use WeakRef;
 # Not documented in the perldoc: This is a simple iterator that just walks
 #  through the nav map and presents the resources in a depth-first search
 #  fashion, ignorant of conditionals, randomized resources, etc. It presents
@@ -3154,7 +3139,7 @@ sub new {
     my $class = ref($proto) || $proto;
     my $self = {};
 
-    $self->{NAV_MAP} = shift;
+    weaken($self->{NAV_MAP} = shift);
     return undef unless ($self->{NAV_MAP});
 
     $self->{FIRST_RESOURCE} = shift || $self->{NAV_MAP}->firstResource();
@@ -3308,7 +3293,7 @@ sub populateStack {
 1;
 
 package Apache::lonnavmaps::resource;
-
+use WeakRef;
 use Apache::lonnet;
 
 =pod
@@ -3390,7 +3375,7 @@ sub new {
     my $class = ref($proto) || $proto;
     my $self = {};
 
-    $self->{NAV_MAP} = shift;
+    weaken($self->{NAV_MAP} = shift);
     $self->{ID} = shift;
 
     # Store this new resource in the parent nav map's cache.