--- loncom/interface/lonhelper.pm	2005/10/11 21:27:44	1.120
+++ loncom/interface/lonhelper.pm	2005/11/22 12:49:50	1.128
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # .helper XML handler to implement the LON-CAPA helper
 #
-# $Id: lonhelper.pm,v 1.120 2005/10/11 21:27:44 albertel Exp $
+# $Id: lonhelper.pm,v 1.128 2005/11/22 12:49:50 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1661,7 +1661,7 @@ sub render {
         $result .= "</select>\n";
     }
     if ($self->{'anytime'}) {
-	    $result.=(<<CHECK);
+	$result.=(<<CHECK);
 <script type="text/javascript">
 // <!--
     function updateCheck(form,name,value) {
@@ -1671,7 +1671,6 @@ sub render {
 // -->
 </script>
 CHECK
-
 	$result.="&nbsp;or&nbsp;<label><input type='checkbox' ";
 	if ($anytime) {
 	    $result.=' checked="checked" '
@@ -2018,6 +2017,18 @@ BUTTONS
 	$mapUrl = $self->{MAP_URL};
     }
 
+    my %defaultSymbs;
+    if (defined($self->{DEFAULT_VALUE})) {
+        my $valueFunc = eval($self->{DEFAULT_VALUE});
+        die 'Error in default value code for variable ' . 
+            $self->{'variable'} . ', Perl said: ' . $@ if $@;
+        my @defaultSymbs = &$valueFunc($helper, $self);
+	if (!$multichoice && @defaultSymbs) { # only allowed 1
+	    @defaultSymbs = ($defaultSymbs[0]);
+	}
+	%defaultSymbs = map { if ($_) {($_,1) } } @defaultSymbs;
+	delete($defaultSymbs{''});
+    }
 
     # Create the composite function that renders the column on the nav map
     # have to admit any language that lets me do this can't be all bad
@@ -2066,13 +2077,21 @@ BUTTONS
 	    }
 
             $col .= "<td align='center'><input type='$inputType' name='${var}.forminput' ";
-            if (!$checked && !$multichoice) {
-                $col .= "checked='checked' ";
-                $checked = 1;
-            }
-	    if ($multichoice) { # all resources start checked; see bug 1174
-		$col .= "checked='checked' ";
-		$checked = 1;
+	    if (%defaultSymbs) {
+		my $symb=$resource->symb();
+		if (exists($defaultSymbs{$symb})) {
+		    $col .= "checked='checked' ";
+		    $checked = 1;
+		}
+	    } else {
+		if (!$checked && !$multichoice) {
+		    $col .= "checked='checked' ";
+		    $checked = 1;
+		}
+		if ($multichoice) { # all resources start checked; see bug 1174
+		    $col .= "checked='checked' ";
+		    $checked = 1;
+		}
 	    }
             $col .= "value='" . $resource_name  . "' /></td>";
 
@@ -2190,6 +2209,10 @@ selection. Defaults to false.
 If true, only active students and course personnel will be
 shown. Defaults to false.
 
+=item * B<emptyallowed>:
+
+If true, the selection of no users is allowed. Defaults to false.
+
 =back
 
 =cut
@@ -2225,6 +2248,7 @@ sub start_student {
     if (defined($token->[2]{'nextstate'})) {
         $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
     }
+    $paramHash->{'emptyallowed'} = $token->[2]{'emptyallowed'};
     
 }    
 
@@ -2346,6 +2370,18 @@ BUTTONS
         $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
     }
 
+    my %defaultUsers;
+    if (defined($self->{DEFAULT_VALUE})) {
+        my $valueFunc = eval($self->{DEFAULT_VALUE});
+        die 'Error in default value code for variable ' . 
+            $self->{'variable'} . ', Perl said: ' . $@ if $@;
+        my @defaultUsers = &$valueFunc($helper, $self);
+	if (!$self->{'multichoice'} && @defaultUsers) { # only allowed 1
+	    @defaultUsers = ($defaultUsers[0]);
+	}
+	%defaultUsers = map { if ($_) {($_,1) } } @defaultUsers;
+	delete($defaultUsers{''});
+    }
     my $choices = [];
 
     # Load up the non-students, if necessary
@@ -2411,7 +2447,13 @@ BUTTONS
         $result .= "<tr><td><input type='$type' name='" .
             $self->{'variable'} . '.forminput' . "'";
             
-        if (!$self->{'multichoice'} && !$checked) {
+	if (%defaultUsers) {
+	    my $user=$choice->[0];
+	    if (exists($defaultUsers{$user})) {
+		$result .= " checked='checked' ";
+		$checked = 1;
+	    }
+	} elsif (!$self->{'multichoice'} && !$checked) {
             $result .= " checked='checked' ";
             $checked = 1;
         }
@@ -2486,9 +2528,14 @@ sub postprocess {
     my $self = shift;
 
     my $result = $env{'form.' . $self->{'variable'} . '.forminput'};
-    if (!$result) {
-        $self->{ERROR_MSG} = 
-	    &mt('You must choose at least one student to continue.');
+    if (!$result && !$self->{'emptyallowed'}) {
+	if ($self->{'coursepersonnel'}) {
+	    $self->{ERROR_MSG} = 
+		&mt('You must choose at least one user to continue.');
+	} else {
+	    $self->{ERROR_MSG} = 
+		&mt('You must choose at least one student to continue.');
+	}
         return 0;
     }
 
@@ -2933,6 +2980,73 @@ sub end_section {
 }    
 1;
 
+package Apache::lonhelper::group;
+
+=pod
+ 
+=head2 Element: groupX<group, helper element>
+ 
+<section> allows the user to choose one or more groups from the current course.
+
+It takes the standard attributes "variable", "multichoice", and "nextstate", meaning what they do for most other elements.
+ 
+=cut
+
+no strict;
+@ISA = ("Apache::lonhelper::choices");
+use strict;
+
+BEGIN {
+    &Apache::lonhelper::register('Apache::lonhelper::group',
+                                 ('group'));
+}
+
+sub new {
+    my $ref = Apache::lonhelper::choices->new();
+    bless($ref);
+}
+ 
+sub start_group {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+ 
+    if ($target ne 'helper') {
+        return '';
+    }
+
+    $paramHash->{CHOICES} = [];
+
+    $paramHash->{'variable'} = $token->[2]{'variable'};
+    $helper->declareVar($paramHash->{'variable'});
+    $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
+    if (defined($token->[2]{'nextstate'})) {
+        $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
+    }
+
+    # Populate the CHOICES element
+    my %choices;
+
+    my $numgroups;
+    my %curr_groups;
+    if (&Apache::loncommon::coursegroups(\%curr_groups)) {
+        foreach my $group_name (keys %curr_groups) {
+            $choices{$group_name} = $group_name;
+        }
+    }
+    foreach my $group_name (sort(keys(%choices))) {
+        push @{$paramHash->{CHOICES}}, [$group_name, $group_name];
+    }
+}
+                                                                                    
+sub end_group {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+    if ($target ne 'helper') {
+        return '';
+    }
+    Apache::lonhelper::group->new();
+}
+1;
+
 package Apache::lonhelper::string;
 
 =pod
@@ -3314,8 +3428,11 @@ sub render {
     }
     my $previous = HTML::Entities::encode(&mt("<- Previous"), '<>&"');
     my $next = HTML::Entities::encode(&mt("Next ->"), '<>&"');
+    my $target = " target='loncapaclient'";
+    if (($env{'browser.interface'} eq 'textual') ||
+        ($env{'environment.remote'} eq 'off')) {  $target='';  }
     $result .= "<center>\n" .
-	"<form action='".$actionURL."' method='post' target='loncapaclient'>\n" .
+	"<form action='".$actionURL."' method='post' $target>\n" .
 	"<input type='button' onclick='history.go(-1)' value='$previous' />" .
 	"<input type='hidden' name='orgurl' value='$targetURL' />" .
 	"<input type='hidden' name='selectrole' value='1' />\n" .
@@ -3516,6 +3633,11 @@ sub render {
         $result .= '<li>'.&mt('for section [_1]',"<b>$section</b>").'</li>';
 	$result .= "<input type='hidden' name='csec' value='" .
             HTML::Entities::encode($section,"'<>&\"") . "' />\n";
+    } elsif ($vars->{TARGETS} eq 'group') {
+        my $group = $vars->{GROUP_NAME};
+        $result .= '<li>'.&mt('for group [_1]',"<b>$group</b>").'</li>';
+        $result .= "<input type='hidden' name='cgroup' value='" .
+            HTML::Entities::encode($group,"'<>&\"") . "' />\n";
     } else {
         # FIXME: This is probably wasteful! Store the name!
         my $classlist = Apache::loncoursedata::get_classlist();