deal with undefined meta

js/main.js

@@ -143,15 +143,17 @@ $(document).ready(function() {
 
 // ==================================================================================
 function fill_metadata(meta) {
-  if (meta.length == 0) {
-    $('#meta-panel').hide();
+  if (meta === undefined || meta.length == 0) {
+    $('#md').hide();
+    $('#meta-collapse').hide();
   } else {
     html = ""
     meta.forEach(item => {
       html += '<p><b>' + item.key + ' = </b>' + item.value + '</p>\n';
     });
     $('#metadata').html(html);
-    $('#meta-panel').show();
+    $('#md').show();
+    $('#meta-collapse').show();
   }
 }
 

run.html

@@ -268,7 +268,7 @@
 
 									<div id="meta-panel" class="panel panel-default" style="margin-bottom:4px;">
 
-										<a id="md" onclick="toggle_metadata_icon()" data-toggle="collapse" href="#collapse1" class="collapsed">
+										<a id="md" onclick="toggle_metadata_icon()" data-toggle="collapse" href="#meta-collapse" class="collapsed">
 											<button class="btn btn-primary btn-sm">Metadata
 												<span id="md-icon" class="glyphicon glyphicon-chevron-right"> </span>
 											</button>
@@ -283,9 +283,9 @@
 											<span href="" class="glyphicon glyphicon-export"></span>
 										</button>
 									</a>
-
 									</div>
-									<div id="collapse1" class="panel-collapse collapse">
+
+									<div id="meta-collapse" class="panel-collapse collapse">
 										<div id="metadata" class="panel-body">
 										</div>
 									</div>