--- loncom/interface/loncommon.pm	2020/10/01 12:34:08	1.1075.2.141.2.9
+++ loncom/interface/loncommon.pm	2020/11/13 02:50:39	1.1075.2.141.2.10
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # a pile of common routines
 #
-# $Id: loncommon.pm,v 1.1075.2.141.2.9 2020/10/01 12:34:08 raeburn Exp $
+# $Id: loncommon.pm,v 1.1075.2.141.2.10 2020/11/13 02:50:39 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -4425,6 +4425,59 @@ sub get_student_view_with_retries {
     }
 }
 
+sub css_links {
+    my ($currsymb,$level) = @_;
+    my ($links,@symbs,%cssrefs,%httpref);
+    if ($level eq 'map') {
+        my $navmap = Apache::lonnavmaps::navmap->new();
+        if (ref($navmap)) {
+            my ($map,undef,$url)=&Apache::lonnet::decode_symb($currsymb);
+            my @resources = $navmap->retrieveResources($map,sub { $_[0]->is_problem() },0,0);
+            foreach my $res (@resources) {
+                if (ref($res) && $res->symb()) {
+                    push(@symbs,$res->symb());
+                }
+            }
+        }
+    } else {
+        @symbs = ($currsymb);
+    }
+    foreach my $symb (@symbs) {
+        my $css_href = &Apache::lonnet::EXT('resource.0.cssfile',$symb);
+        if ($css_href =~ /\S/) {
+            unless ($css_href =~ m{https?://}) {
+                my $url = (&Apache::lonnet::decode_symb($symb))[-1];
+                my $proburl =  &Apache::lonnet::clutter($url);
+                my ($probdir) = ($proburl =~ m{(.+)/[^/]+$});
+                unless ($css_href =~ m{^/}) {
+                    $css_href = &Apache::lonnet::hreflocation($probdir,$css_href);
+                }
+                if ($css_href =~ m{^/(res|uploaded)/}) {
+                    unless (($httpref{'httpref.'.$css_href}) ||
+                            (&Apache::lonnet::is_on_map($css_href))) {
+                        my $thisurl = $proburl;
+                        if ($env{'httpref.'.$proburl}) {
+                            $thisurl = $env{'httpref.'.$proburl};
+                        }
+                        $httpref{'httpref.'.$css_href} = $thisurl;
+                    }
+                }
+            }
+            $cssrefs{$css_href} = 1;
+        }
+    }
+    if (keys(%httpref)) {
+        &Apache::lonnet::appenv(\%httpref);
+    }
+    if (keys(%cssrefs)) {
+        foreach my $css_href (keys(%cssrefs)) {
+            next unless ($css_href =~ m{^(/res/|/uploaded/|https?://)});
+            $links .= '<link rel="stylesheet" type="text/css" href="'.$css_href.'" />'."\n";
+        }
+    }
+    return $links;
+}
+
 =pod
 
 =item * &get_student_answers()