rollback-related.js

/* app/mixins/rollback.js */
import Ember from 'ember';
const { run } = Ember;

var Rollback = Ember.Mixin.create({
  rollbackRelationships() {
    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(`${name}Id`);
        if(belongsToId !== oldId){
          const originalRecord = model.store.peekRecord(meta.type, oldId);
          run(() => {
            // reset 'location' to old
            model.set(name, originalRecord);
          });
        } 
      }
      else if(meta.kind === 'hasMany') {
        const m2mIds = this.get(`${name}Ids`) || [];
        const current_m2mIds = this.get(name).mapBy('id');
        let updated_arr = [];
        m2mIds.forEach((oldId) => {
          if(!current_m2mIds.includes(oldId)){
            // if not in array, then removed and need to add back
            const originalRecord = model.store.peekRecord(meta.type, oldId);
            updated_arr.push(originalRecord);
          } else {
            //if in array, then added
            const record = model.store.peekRecord(meta.type, oldId);
            updated_arr.push(record);
          }
        });
        model.set(name, updated_arr);
      }
    });
  },
});
export default Rollback;