Pass last_fetched_at for notes to javascript

app/assets/javascripts/notes.js.coffee

 class Notes
   @interval: null
 
-  constructor: (notes_url, note_ids) ->
+  constructor: (notes_url, note_ids, last_fetched_at) ->
     @notes_url = notes_url
     @notes_url = gon.relative_url_root + @notes_url if gon.relative_url_root?
     @note_ids = note_ids
+    @last_fetched_at = last_fetched_at
     @initRefresh()
     @setupMainTargetNoteForm()
     @cleanBinding()
@@ -76,9 +77,11 @@ class Notes
   getContent: ->
     $.ajax
       url: @notes_url
+      data: "last_fetched_at=" + @last_fetched_at
       dataType: "json"
       success: (data) =>
         notes = data.notes
+        @last_fetched_at = data.last_fetched_at
         $.each notes, (i, note) =>
           @renderNote(note)
 

app/controllers/projects/notes_controller.rb

@@ -5,9 +5,10 @@ class Projects::NotesController < Projects::ApplicationController
   before_filter :authorize_admin_note!, only: [:update, :destroy]
 
   def index
+    current_fetched_at = Time.now
     @notes = NotesFinder.new.execute(project, current_user, params)
 
-    notes_json = { notes: [] }
+    notes_json = { notes: [], last_fetched_at: current_fetched_at }
 
     @notes.each do |note|
       notes_json[:notes] << {

app/views/projects/notes/_notes_with_form.html.haml

@@ -7,4 +7,4 @@
   = render "projects/notes/form"
 
 :javascript
-  new Notes("#{project_notes_path(target_id: @noteable.id, target_type: @noteable.class.name.underscore)}", #{@notes.map(&:id).to_json})
+  new Notes("#{project_notes_path(target_id: @noteable.id, target_type: @noteable.class.name.underscore)}", #{@notes.map(&:id).to_json}, Time.now)