controller.coffee

class App.SalesSummaryReportController extends Ember.ObjectController
  currentInterval: null

  +observer interval
  intervalChanged: ->
    return if @interval == @currentInterval

    @transitionToRoute 'sales_summary_report', interval: @interval

route.coffee

class App.SalesSummaryReportRoute extends App.AuthenticatedRoute
  model: (params) ->
    new Promise (resolve, reject) ->
      $.getJSON '/api/v0/sales_summary', interval: params.interval, (data) ->
        resolve(data.report)

  setupController: (controller, model) ->
    controller.set 'currentInterval', model.interval
    @_super(controller, model)