save-related.js

/* app/mixins/save-related.js */
import Ember from 'ember';
import equal from 'example-app/utils/equal';
const { run } = Ember;

var SaveRelated = Ember.Mixin.create({
  saveRelated() {
    const model = this;
    this.eachRelationship((name, meta) => {
      const related_model = model.get(name);
      if(meta.kind === 'belongsTo'){
        const belongsToId = related_model && related_model.get('id');
        const oldId = model.get(`${name}Id`);
        if(belongsToId !== oldId) {
          run(() => {
            model.set(`${name}Id`, belongsToId);
          });
        } 
      }
      else if(meta.kind === 'hasMany'){
        const current_m2m_ids = model.get(name).mapBy('id');
        const m2m_ids = this.get(`${name}Ids`);
        if(!equal(current_m2m_ids, m2m_ids)) {
          run(() => {
            model.set(`${name}Ids`, current_m2m_ids);
          });
        } 
      }
    });
  },
});
export default SaveRelated;