Question

我尝试设置属性的默认值，具体取决于正在加载的模型的其他属性。

模型加载后如何触发setOthers方法？ totalPoints 属性可以随后更改，用户还应该能够从 setOthers 方法中设置的初始值更改其他值

我有这个用户模型：

App.User = DS.Model.extend(
  # [ ... ]
  competenceRatings: DS.attr('competenceRatings')
)

这是控制器：

App.UsersEditController = Ember.ObjectController.extend(
  others: 0 # Set others to remaining points, if points > 0 and less than 100.

  totalPoints: (->
    totalPoints = @get('others')
    totalPoints += competenceRating.get('points') for competenceRating in @get('competenceRatings')
    totalPoints
  ).property('competenceRatings.@each.points', 'others')

  setOthers: ->
    totalPoints = @get('totalPoints')
    if totalPoints > 0 and totalPoints < 100
      @set('others', 100 - totalPoints)
)

我已经尝试http://emberjs.com/api/#method_computed_defaultTo：

App.UsersEditController = Ember.ObjectController.extend(
  others: Ember.computed.defaultTo('setOthers') # Set others to remaining points, if points > 0 and less than 100.

  totalPoints: (->
    totalPoints = @get('others')
    totalPoints += competenceRating.get('points') for competenceRating in @get('competenceRatings')
    totalPoints
  ).property('competenceRatings.@each.points', 'others')

  setOthers: (->
    console.log @get('isLoaded')
    value = 0
    totalPoints = @get('totalPoints')
    if totalPoints > 0 and totalPoints < 100
      #@set('others', 100 - totalPoints)
      value = 100 - totalPoints
    value
  ).property()
)

这是输出：

true employeenet.js:105386
true employeenet.js:105386
[ ... repeated many, many... many times ... ]
true employeenet.js:105386
<error> VM1936:1
<error> VM1936:1
Uncaught RangeError: Maximum call stack size exceeded employeenet.js:1
Error: Assertion Failed: Emptying a view in the inBuffer state is not allowed and should not happen under normal circumstances. Most likely there is a bug in your application. This may be due to excessive property change notifications.
    at new Error (native)
    at Error.Ember.Error (http://localhost:3000/assets/employeenet.js:47844:19)
    at Object.Ember.assert (http://localhost:3000/assets/employeenet.js:47073:11)
    at Object.Ember.merge.empty (http://localhost:3000/assets/employeenet.js:71691:11)
    at Ember.CollectionView.Ember.ContainerView.extend.arrayWillChange (http://localhost:3000/assets/employeenet.js:72618:25)
    at Object.sendEvent (http://localhost:3000/assets/employeenet.js:49537:14)
    at Ember.Array.Ember.Mixin.create.arrayContentWillChange (http://localhost:3000/assets/employeenet.js:62031:11)
    at Ember.ArrayProxy.Ember.Object.extend.arrangedContentArrayWillChange (http://localhost:3000/assets/employeenet.js:66416:10)
    at null._arrangedContentWillChange (http://localhost:3000/assets/employeenet.js:66266:10)
    at sendEvent (http://localhost:3000/assets/employeenet.js:49537:14) employeenet.js:50461
Uncaught Error: Assertion Failed: Error: Assertion Failed: Emptying a view in the inBuffer state is not allowed and should not happen under normal circumstances. Most likely there is a bug in your application. This may be due to excessive property ...<omitted>...s. employeenet.js:47073
Error: Assertion Failed: Emptying a view in the inBuffer state is not allowed and should not happen under normal circumstances. Most likely there is a bug in your application. This may be due to excessive property change notifications.
    at new Error (native)
    at Error.Ember.Error (http://localhost:3000/assets/employeenet.js:47844:19)
    at Object.Ember.assert (http://localhost:3000/assets/employeenet.js:47073:11)
    at Object.Ember.merge.empty (http://localhost:3000/assets/employeenet.js:71691:11)
    at Ember.CollectionView.Ember.ContainerView.extend.arrayWillChange (http://localhost:3000/assets/employeenet.js:72618:25)
    at Object.sendEvent (http://localhost:3000/assets/employeenet.js:49537:14)
    at Ember.Array.Ember.Mixin.create.arrayContentWillChange (http://localhost:3000/assets/employeenet.js:62031:11)
    at Ember.ArrayProxy.Ember.Object.extend.arrangedContentArrayWillChange (http://localhost:3000/assets/employeenet.js:66416:10)
    at null._arrangedContentWillChange (http://localhost:3000/assets/employeenet.js:66266:10)
    at sendEvent (http://localhost:3000/assets/employeenet.js:49537:14) employeenet.js:50461
Uncaught Error: Assertion Failed: Error: Assertion Failed: Emptying a view in the inBuffer state is not allowed and should not happen under normal circumstances. Most likely there is a bug in your application. This may be due to excessive property ...<omitted>...s. employeenet.js:47073

Answer 1

查看Ember.computed.defaultTo。

这样的事情应该有效：

App.UsersEditController = Ember.ObjectController.extend(
  others: Ember.computed.defaultTo('othersDefault')

  totalPoints: (->
    totalPoints = @get('others')
    totalPoints += competenceRating.get('points') for competenceRating in @get('competenceRatings')
    totalPoints
  ).property('competenceRatings.@each.points', 'others')

  othersDefault: (->
    totalPoints = @get('totalPoints')
    if totalPoints > 0 and totalPoints < 100
      @set('others', 100 - totalPoints)
  ).property()

Ember.js设置属性的初始值

1 个答案: