Ember data custom store function able to find entity by custom field not id only. Usefull for finding by secondary keys as slug or name.

store.js

// for ember-cli place in app/store.js

import Ember from 'ember';
import DS from 'ember-data';

export default DS.Store.extend({

  /**
   * Acts as find(type, id) but can be used on any field.
   * @param type
   * @param field
   * @param value
   * @return {Promise} promise
   */
  findAsId: function (type, field, value) {
    Ember.assert("You need to pass a type, field and value.", arguments.length === 3);

    var entity = this.all(type).findBy(field, value);
    if (Ember.isEmpty(entity)) {
      var query = {};
      query[field] = value;
      return this.find(type, query).then(function (array) {
        Ember.assert('Must find only one object. Found:' + array.get('length'), array.get('length') === 1);
        return array.get('firstObject');
      });
    } else {
      return new Ember.RSVP.Promise(function(resolve){
        resolve(entity);
      });
    }
  }
});