--- loncom/lonnet/perl/lonnet.pm	2017/11/30 15:15:06	1.1361
+++ loncom/lonnet/perl/lonnet.pm	2017/12/18 23:14:03	1.1362
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1361 2017/11/30 15:15:06 raeburn Exp $
+# $Id: lonnet.pm,v 1.1362 2017/12/18 23:14:03 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -7504,7 +7504,10 @@ sub allowed {
 # Free bre to public access
 
     if ($priv eq 'bre') {
-        my $copyright=&metadata($uri,'copyright');
+        my $copyright;
+        unless ($uri =~ /ext\.tool/) {
+            $copyright=&metadata($uri,'copyright');
+        }
 	if (($copyright eq 'public') && (!$env{'request.course.id'})) { 
            return 'F'; 
         }
@@ -11491,9 +11494,13 @@ sub EXT {
 	} else {
 	    $filename=$env{'request.filename'};
 	}
-	my $metadata=&metadata($filename,$what);
+        my $toolsymb;
+        if (($filename =~ /ext\.tool$/) && ($what ne '0_gradable')) {
+            $toolsymb = $symbparm;
+        }
+	my $metadata=&metadata($filename,$what,$toolsymb);
 	if (defined($metadata)) { return &get_reply([$metadata,'resource']); }
-	$metadata=&metadata($filename,'parameter_'.$what);
+	$metadata=&metadata($filename,'parameter_'.$what,$toolsymb);
 	if (defined($metadata)) { return &get_reply([$metadata,'resource']); }
 
 # ----------------------------------------------- fifth, look in rest of course
@@ -11519,7 +11526,7 @@ sub EXT {
 	    if (defined($partgeneral[0])) { return &get_reply(\@partgeneral); }
 	}
 	if ($recurse) { return undef; }
-	my $pack_def=&packages_tab_default($filename,$varname);
+	my $pack_def=&packages_tab_default($filename,$varname,$toolsymb);
 	if (defined($pack_def)) { return &get_reply([$pack_def,'resource']); }
 # ---------------------------------------------------- Any other user namespace
     } elsif ($realm eq 'environment') {
@@ -11613,11 +11620,11 @@ sub sort_course_groups { # Sort groups b
 }
 
 sub packages_tab_default {
-    my ($uri,$varname)=@_;
+    my ($uri,$varname,$toolsymb)=@_;
     my (undef,$part,$name)=split(/\./,$varname);
 
     my (@extension,@specifics,$do_default);
-    foreach my $package (split(/,/,&metadata($uri,'packages'))) {
+    foreach my $package (split(/,/,&metadata($uri,'packages',$toolsymb))) {
 	my ($pack_type,$pack_part)=split(/_/,$package,2);
 	if ($pack_type eq 'default') {
 	    $do_default=1;
@@ -11685,7 +11692,7 @@ sub add_prefix_and_part {
 my %metaentry;
 my %importedpartids;
 sub metadata {
-    my ($uri,$what,$liburi,$prefix,$depthcount)=@_;
+    my ($uri,$what,$toolsymb,$liburi,$prefix,$depthcount)=@_;
     $uri=&declutter($uri);
     # if it is a non metadata possible uri return quickly
     if (($uri eq '') || 
@@ -11709,6 +11716,57 @@ sub metadata {
 	my ($result,$cached)=&is_cached_new('meta',$uri);
 	if (defined($cached)) { return $result->{':'.$what}; }
     }
+
+#
+# If the uri is for an external tool the file from
+# which metadata should be retrieved depends on whether
+# the tool had been configured to be gradable (set in the Course
+# Editor or Resource Editor).
+#
+# If a valid symb has been included as the third arg in the call
+# to &metadata() that can be used to retrieve the value of
+# parameter_0_gradable set for the resource, and included in the
+# uploaded map containing the tool. The value is retrieved via
+# &EXT(), if a valid symb is available.  Otherwise the value of
+# gradable in the exttool_$marker.db file for the tool instance
+# is retrived via &get().
+#
+# In order to avoid an infinite loop, &metadata() will return
+# before a call to &EXT(), if the uri is for an external tool
+# and the $what for which metadata is being requested is
+# parameter_0_gradable or 0_gradable.
+#
+
+    if ($uri =~ /ext\.tool$/) {
+        if (($what eq 'parameter_0_gradable') || ($what eq '0_gradable')) {
+            return;
+        } else {
+            my ($checked,$use_passback);
+            if ($toolsymb ne '') {
+                (undef,undef,my $tooluri) = &decode_symb($toolsymb);
+                if ($tooluri eq $uri) {
+                    $checked = 1;
+                    if (&EXT('resource.0.gradable',$toolsymb) =~ /^yes$/i) {
+                        $use_passback = 1;
+                    }
+                }
+            }
+            unless ($checked) {
+                my ($ignore,$cdom,$cnum,$marker) = split(m{/},$uri);
+                $marker=~s/\D//g;
+                if (!$marker) {
+                    my %toolsettings=&get('exttool_'.$marker,['gradable'],$cdom,$cnum);
+                    $use_passback = $toolsettings{'gradable'};
+                }
+            }
+            if ($use_passback) {
+                $filename = '/home/httpd/html/res/lib/templates/LTIpassback.tool';
+            } else {
+                $filename = '/home/httpd/html/res/lib/templates/LTIstandard.tool';
+            }
+        }
+    }
+
     {
 # Imported parts would go here
         my %importedids=();
@@ -11848,7 +11906,7 @@ sub metadata {
 
 			if ($depthcount<20) {
 			    my $metadata = 
-				&metadata($uri,'keys', $location,$unikey,
+				&metadata($uri,'keys',$toolsymb,$location,$unikey,
 					  $depthcount+1);
 			    foreach my $meta (split(',',$metadata)) {
 				$metaentry{':'.$meta}=$metaentry{':'.$meta};
@@ -11923,7 +11981,7 @@ sub metadata {
 		$dir=~s|[^/]*$||;
 		$location=&filelocation($dir,$location);
 		my $rights_metadata =
-		    &metadata($uri,'keys',$location,'_rights',
+		    &metadata($uri,'keys',$toolsymb,$location,'_rights',
 			      $depthcount+1);
 		foreach my $rights (split(',',$rights_metadata)) {
 		    #$metaentry{':'.$rights}=$metacache{$uri}->{':'.$rights};
@@ -14670,10 +14728,14 @@ condval($condidx) : value of condition i
 
 =item *
 
-metadata($uri,$what,$liburi,$prefix,$depthcount) : request a
+metadata($uri,$what,$toolsymb,$liburi,$prefix,$depthcount) : request a
 resource's metadata, $what should be either a specific key, or either
 'keys' (to get a list of possible keys) or 'packages' to get a list of
-packages that this resource currently uses, the last 3 arguments are only used internally for recursive metadata.
+packages that this resource currently uses, the last 3 arguments are 
+only used internally for recursive metadata.
+
+the toolsymb is only used where the uri is for an external tool (for which
+the uri as well as the symb are guaranteed to be unique).
 
 this function automatically caches all requests