             , (err)=>
               handler = @["on#{_.string.capitalize(_.string.camelize(k))}Error"]
               handler = onDataError.bind(@, k) unless _.isFunction(handler)
+              errors[k] = err
               promiseDfd.resolve(handler err)
             promiseDfd
 

      # afterRender
      # Start nested widgets...
      render: (tpl, data)=>
        ctx = @buildContext.call(@)
        ctx.fail (err)->
          console.error("Error fetching Datasources ", err.message, err)
        ctx.then (ctx)=>
          try
            beforeCtx = @beforeRender.call(@, ctx)
            beforeRendering = $.when(beforeCtx)
            beforeRendering.done (dataAfterBefore)=>
              data = _.extend(dataAfterBefore || ctx, data)

        @_renderCount ?= 0
        @_renderCount++
        ret       = {}
        errors    = {}
        dfd       = @sandbox.data.deferred()
        try
          keys      = _.keys(@datasources)
