Add empty list indicator for Physical Web WebUI

components/physical_web/webui/resources/physical_web.js

Index: components/physical_web/webui/resources/physical_web.js
diff --git a/components/physical_web/webui/resources/physical_web.js b/components/physical_web/webui/resources/physical_web.js
index 418dc1d6e90c1b5e8daffb35b8fbd841900eae08..79305086614e2cd1f30c1256bd13f05964bd3b5f 100644
--- a/components/physical_web/webui/resources/physical_web.js
+++ b/components/physical_web/webui/resources/physical_web.js
@@ -24,8 +24,12 @@ function physicalWebItemClicked(index) {
 function returnNearbyURLs(nearbyUrlsData) {
   var bodyContainer = $('body-container');
   renderTemplate(nearbyUrlsData);
-
   bodyContainer.style.visibility = 'visible';

[cco3, 2017/02/23 23:36:54]

Just use the appropriate jquery method:
$('#body-container').show()

[cco3, 2017/02/23 23:39:33]

I saw your other comment.  This is definitely using some kind of jquery; `$` is
the jquery function.  You should be able to call show or .css('display, 'none').

I'm not sure why it would work without the #, but not with the hash.

[Ran, 2017/02/24 18:52:59]

The show and hide() function is not available, I guess it's not jQuery here.

+
+  if (nearbyUrlsData['metadata'].length == 0) {
+    var emptyMessage = $('empty-container');
+    emptyMessage.style.visibility = 'visible';
+  }
 }
 
 document.addEventListener('DOMContentLoaded', requestNearbyURLs);