ember-data v1.0.0中的单表继承

时间:2013-10-25 01:52:35

标签: ember.js ember-data

我正在将余烬应用程序从ember-data v0.13 迁移到 v1.0.0

在版本v0.13中,RESTSerializer曾经有一个实现回调,允许我将rails STI模型映射到ember模型。

因此,当我得到不同类型的事件列表时,我会将每个事件转换为适当的余烬模型

"events": [
    {
        "id": 1,
        "type": "cash_inflow_event",
        "time": "2012-05-31T00:00:00-03:00",
        "value": 30000
    },
    {
        "id": 2,
        "type": "asset_bought_event",
        "asset_id": 119,
        "time": "2012-08-16T00:00:00-03:00",
        "quantity": 100
    }
]

Ember模特

App.Event = DS.Model.extend({...})
App.AssetBoughtEventMixin = Em.Mixin.create({...})
App.AssetBoughtEvent = App.Event.extend(App.AssetBoughtEventMixin)
App.CashInflowEventMixin = Em.Mixin.create({...})
App.CashInflowEvent = App.Event.extend(App.CashInflowEventMixin)

Ember-data code v0.13创建了类似STI的余烬模型

App.RESTSerializer = DS.RESTSerializer.extend({
    materialize:function (record, serialized, prematerialized) {
        var type = serialized.type;
        if (type) {
            var mixin = App.get(type.classify() + 'Mixin');
            var klass = App.get(type.classify());
            record.constructor = klass;
            record.reopen(mixin);
        }
        this._super(record, serialized, prematerialized);
    },

    rootForType:function (type) {
        if (type.__super__.constructor == DS.Model) {
            return this._super(type);
        }
        else {
            return this._super(type.__super__.constructor);
        }
    }
});

如何在ember-data v1.0.0 中做同样的事情?

2 个答案:

答案 0 :(得分:2)

我想我有一个解决方案......

模型上有一个setupData回调。 我做了以下

App.Event = DS.Model.extend({
    ...
    setupData:function (data, partial) {
        var type = data.type;
        if (type) {
            var mixin = App.get(type.classify() + 'Mixin');
            this.reopen(mixin);
        }
        delete data.type;
        this._super(data, partial);
    },
    eachAttribute: function() {
        if(this.get('type')){
          var constructor = App.get(this.get('type').classify());
          constructor.eachAttribute.apply(constructor, arguments);
        }
        this._super.apply(this, arguments);
     }
});

Ember专家,这是一个好主意吗?

答案 1 :(得分:1)

首先,由于您使用的是Rails,因此您可能需要使用ActiveModelAdapter&从序列化程序扩展自定义序列化程序:

App.ApplicationAdapter = DS.ActiveModelAdapter;
App.ApplicationSerializer = DS.ActiveModelSerializer.extend({...});

您的自定义序列化程序应该覆盖typeForRoot&可能是normalize。以下是这些方法现在的样子:

DS.ActiveModelSerializer#typeForRoot

typeForRoot: function(root) {
  var camelized = Ember.String.camelize(root);
  return Ember.String.singularize(camelized);
}

DS.JSONSerializer#normalize

normalize: function(type, hash) {
  if (!hash) { return hash; }

  this.applyTransforms(type, hash);
  return hash;
}