javascript - Ember.js 如何拦截和过滤传递给 Ember.Object.create(params) 的参数

Question

App.Person = Ember.Object.extend({
  firstName: "Trek",
});

App.person = App.Person.create({
  firstName: undefined
})

console.log(App.person.get('firstName')); 

此代码将输出undefined，但我想以某种方式拦截属性设置，如果它设置为undefined ，则保持默认值“ Trek ”不变。

ember-1.0.0

Answer 1

使用计算属性和默认值

App.Person = Ember.Object.extend({
    firstNameDefault:'Trek',
    firstName:function(key,value){
        if(arguments.length > 1 && typeof value !== 'undefined'){
            return value
        }
        return this.get('firstNameDefault');
    }.property('firstNameDefault')
});

App.person = App.Person.create({
  firstName: undefined
})

console.log(App.person.get('firstName')); 

Answer 2

您可以使用计算属性：

App.Person = Ember.Object.extend({
  _firstName: 'Trek',
  firstName: function(key, value) {
    if (arguments.length > 1 && typeof value !== 'undefined') {
      this.set('_firstName', value);
    }

    return this.get('_firstName');
  }.property('_firstName')
});

App.person = App.Person.create({
  firstName: undefined
})

console.log(App.person.get('firstName'));