Question

我有两个相关的模型：

//models/school.js
import DS from 'ember-data';
import { belongsTo } from 'ember-data/relationships';
import { hasMany } from 'ember-data/relationships';

export default DS.Model.extend({
    name: DS.attr('string'),
    zipCode: DS.attr('string'),

    kids: hasMany('kid',{inverse: 'schoolId',async:true}),
    district: belongsTo('district',{inverse:'schools',async:true}),
    grades: hasMany('grade',{inverse: 'schools'}),  
});

//models/district.js
import DS from 'ember-data';
import { hasMany } from 'ember-data/relationships';

export default DS.Model.extend({

      name: DS.attr('string'),
      zipCode: DS.attr('string'),
      schools: hasMany('school',{inverse: 'district',async:true}),
});

Accordind到文档https://guides.emberjs.com/v2.2.0/models/relationships/#toc_relationships-as-promises，当我试图通过学校到达学区时，有时学区会返回null，就像学校与任何学区没有关系一样，但所有学校都与学区有关。我不明白这一点。

//routes/kid-info.js

import Ember from 'ember';

export default Ember.Route.extend({

setupController(controller,model){ //the model is kid
    this._super(controller,model);
    controller.set('districts',this.store.findAll('district'));
    controller.set('schools',this.store.findAll('school'));
    controller.set('grades',this.store.findAll('grade'));
    var schoolId=model.get('schoolId.id');
    controller.set('selectedSchool',model.get('schoolId'));
    let school=this.store.peekRecord('school',schoolId);
    if(school){
        school.get('district').then((district)=>{
            controller.set('selectedDistrict',district); //the district is sometimes null
        });
      }

},

更新

根据@Thernys的建议，我改变了这样的路线：

import Ember from 'ember';

export default Ember.Route.extend({

setupController(controller,model){
    this._super(controller,model);

    controller.set('districts',this.store.peekAll('district'));
    controller.set('schools',this.store.peekAll('school'));
    controller.set('grades',this.store.peekAll('grade'));

    controller.set('selectedSchool',model.get('schoolId'));

    model.get('schoolId.district').then(function(district) {
     controller.set('selectedDistrict',district);
    });

},

但我仍然有相同的结果。就像学校与学区没有正确关系一样。 JIC我在设置控制器呼叫之前加载了学校和学区。

Answer 1

这最终解决了我的问题：

model.get('schoolId').then(function(school) {
        controller.set('selectedDistrict',that.store.peekRecord('district',school.get('district_id')));
    });

作为承诺的恩赐关系

1 个答案: