Disable the post button when the annotation has no content

Card 89

h/static/scripts/directive/annotation.coffee

@@ -133,6 +133,15 @@ AnnotationController = [
       else if privacy == 'shared'
         this.setShared()
 
+    ###*
+    # @ngdoc method
+    # @name annotation.AnnotaitonController#hasContent
+    # @returns {boolean} True if the currently edited annotation has
+    #          content (ie. is not just a highlight)
+    ###
+    this.hasContent = ->
+      @annotation.text?.length > 0 || @annotation.tags?.length > 0
+
     ###*
     # @ngdoc method
     # @name annotation.AnnotationController#authorize

h/templates/client/annotation.html

@@ -116,6 +116,7 @@
               class="dropdown-menu-btn"><i class="h-icon-check btn-icon"></i> Delete</button>
       <publish-annotation-btn
         group="vm.group()"
+        can-post="vm.hasContent()"
         is-new="vm.action == 'create'"
         is-shared="vm.isShared()"
         on-save="vm.save()"