错误：未在Angular自定义服务中使用google定义

Question

有以下自定义Angular服务：

angular.module('app.services', ['uiGmapgoogle-maps']).factory('Geocoder', ['$q', ($q) ->
  geocoder = new google.maps.Geocoder()

  geocode: (location) ->
    defer = $q.defer()
    geocoder.geocode { location: location }, (results, status) ->
      if status is google.maps.GeocoderStatus.OK
        defer.resolve(results[0].formatted_address)
      else
        defer.reject()
    defer.promise()
])

当我尝试在某个控制器中执行Geocoder.geocode（...）时，我收到错误＆＃34;谷歌未定义＆＃34;，但如果我使用＆＃39; google.maps.Geocoder＆＃39 ;在控制器中它运作良好。我的主要模块：

module = angular.module('app', ['app.controllers', 'app.directives',
  'app.services', 'ui.bootstrap', 'ui.router', 'uiGmapgoogle-maps', 'dndLists'])

module.config(['$locationProvider', '$stateProvider', '$urlRouterProvider',
  '$httpProvider', 'uiGmapGoogleMapApiProvider', ($locationProvider,
  $stateProvider, $urlRouterProvider, $httpProvider,
  uiGmapGoogleMapApiProvider) ->

    uiGmapGoogleMapApiProvider.configure(
      key: 'MYKEY'
      libraries: 'places, geocoder'
      v: '3.17')

    $stateProvider.state('home'
      url: ''
      controller: 'HomeController'
      templateUrl: 'templates/home.html'
    )

    $urlRouterProvider.otherwise ($injector) ->
      $state = $injector.get('$state')
      $state.go('home')

    $locationProvider.html5Mode(true)
])

如您所见，我加载了Google地图。问题是什么？谢谢！