INT-155 show "no documents found" message when result is empty.

either if there are no documents in the collection, or if the refine query returned 0 documents.

Author: rueckstiess

src/home/collection.jade

@@ -7,18 +7,22 @@
       .col-md-6
         div(data-hook='stats-subview')
   div(data-hook='refine-bar')
-  .column-container(data-hook='json-sidebar-toggle-class')
-    .column.main
-      div(data-hook='fields-subview')
-    .splitter
-      button.btn.btn-link.splitter-button.splitter-button-open(title='View Sampled Documents')
-        i.fa.fa-caret-left
-        |  
-        i.fa.fa-file-text-o
+  div.hidden(data-hook='empty')
+    ul.message-background.with-sidebar.centered: li
+      p No documents found.
+  div(data-hook='non-empty')
+    .column-container(data-hook='json-sidebar-toggle-class')
+      .column.main
+        div(data-hook='fields-subview')
+      .splitter
+        button.btn.btn-link.splitter-button.splitter-button-open(title='View Sampled Documents')
+          i.fa.fa-caret-left
+          |  
+          i.fa.fa-file-text-o
 
-      button.btn.btn-link.splitter-button.splitter-button-close(title='Hide Sampled Documents')
-        i.fa.fa-file-text-o
-        |  
-        i.fa.fa-caret-right
-    .column.side
-      div(data-hook='documents-subview')
+        button.btn.btn-link.splitter-button.splitter-button-close(title='Hide Sampled Documents')
+          i.fa.fa-file-text-o
+          |  
+          i.fa.fa-caret-right
+      .column.side
+        div(data-hook='documents-subview')

src/home/collection.js

@@ -42,8 +42,22 @@ var MongoDBCollectionView = View.extend({
     model: MongoDBCollection,
     schema: SampledSchema
   },
+  showEmptyMessage: function() {
+    this.queryByHook('empty').classList.remove('hidden');
+    this.queryByHook('non-empty').classList.add('hidden');
+  },
+  hideEmptyMessage: function() {
+    if (!this.rendered) return;
+    this.queryByHook('empty').classList.add('hidden');
+    this.queryByHook('non-empty').classList.remove('hidden');
+  },
+  onSchemaSync: function() {
+    (this.schema.sample_size === 0) ? this.showEmptyMessage() : this.hideEmptyMessage();
+  },
   initialize: function() {
     app.statusbar.watch(this, this.schema);
+    this.listenTo(this.schema, 'sync', this.onSchemaSync.bind(this));
+    this.listenTo(this.schema, 'request', this.hideEmptyMessage.bind(this));
     this.listenTo(app.queryOptions, 'change', this.onQueryChanged.bind(this));
     this.listenToAndRun(this.parent, 'change:ns', this.onCollectionChanged.bind(this));
   },
@@ -55,7 +69,7 @@ var MongoDBCollectionView = View.extend({
       return;
     }
     this.visible = true;
-
+    this.hideEmptyMessage();
     this.schema.ns = this.model._id = ns;
     debug('updating namespace to `%s`', ns);
     this.schema.reset();