Ember-data 2：如何在不存储的情况下从服务器获取记录来检索belongsTo模型ID

Question

I have an activity model that belongs to a report . I have a scenario where I have only the activity records and all I want to do is get the report id, without fetching the whole record.

activity.get('report_id') // undefined

activity.get('report.id') // the id! But after a full fetch

Obviously, it knows the id, but I can't figure out the right incantation. Anyone have any thoughts?

ps. It looks like this changed in ember-data 2 so a previous answer will not work.

-------------------------------
Ember             : 2.4.1
Ember Data        : 2.4.0+9f8c40927a
jQuery            : 1.11.3
Ember Simple Auth : 1.0.0
-------------------------------

Answer 1

我不认为在Release通道中可以做到这一点，但是如果您使用Canary并启用ds-references功能标记 ，则可以使用RFC 57中列出的功能。

Answer 2

Though locks answer was very helpful in understanding the direction this is going, it's not immediately practical. The RFC have a comment with a simple solution for right now.

1. Add a new id attribute to the model
2. Populate in the serializer

https://github.com/emberjs/rfcs/pull/57#issuecomment-121008369

//models/report-activity.js
export default DS.Model.extend({
  report: belongsTo('report', {async: true}),
  reportId: attr('string'), //set in serializer
});

//serializers/report-activiy.js
export default DS.ActiveModelSerializer.extend({
  normalizeAttributes(typeClass, hash) {
    if (hash.report_id) {
      hash.reportId = hash.report_id;
    }

    return this._super(typeClass, hash);
  }
});