Pushing Records into the Store

Pushing Records into the Store

One way to think about the store is as a cache of all of the records that have been loaded by your application. If a route or a controller in your app asks for a record, the store can return it immediately if it is in the cache. Otherwise, the store must ask the adapter to load it, which usually means a trip over the network to retrieve it from the server.

Instead of waiting for the app to request a record, however, you can push records into the store's cache ahead of time.

This is useful if you have a good sense of what records the user will need next. When they click on a link, instead of waiting for a network request to finish, Ember.js can render the new template immediately. It feels instantaneous.

Another use case for pushing in records is if your application has a streaming connection to a backend. If a record is created or modified, you want to update the UI immediately.

Pushing Records

To push a record into the store, call the store's push() method.

For example, imagine we want to preload some data into the store when the application boots for the first time.

We can use the route:application to do so. The route:application is the top-most route in the route hierarchy, and its model hook gets called once when the app starts up.

import DS from 'ember-data';

export default DS.Model.extend({
  title: DS.attr(),
  artist: DS.attr(),
  songCount: DS.attr()
});

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    this.get('store').push({
      data: [{
        id: 1,
        type: 'album',
        attributes: {
          title: 'Fewer Moving Parts',
          artist: 'David Bazan',
          songCount: 10
        },
        relationships: {}
      }, {
        id: 2,
        type: 'album',
        attributes: {
          title: 'Calgary b/w I Can\'t Make You Love Me/Nick Of Time',
          artist: 'Bon Iver',
          songCount: 2
        },
        relationships: {}
      }]
    });
  }
});

The store's push() method is a low level API which accepts a JSON API document with a few important differences from the JSON API document that the JSONAPISerializer accepts. The type name in the JSON API document must match the type name of the model exactly (In the example above the type is album because the model is defined in app/models/album.js). Attributes and relationship names must match the casing of the properties defined on the Model class.

If you would like the data to be normalized by the model's default serializer before pushing it into the store, you can use the store.pushPayload() method.

import DS from 'ember-data';

export default DS.RestSerializer.extend({
  normalize(typeHash, hash) {
    hash['songCount'] = hash['song_count']
    delete hash['song_count']
    return this._super(typeHash, hash);
  }

})

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    this.get('store').pushPayload({
      albums: [
        {
          id: 1,
          title: 'Fever Moving Parts',
          artist: 'David Bazan',
          song_count: 10
        },
        {
          id: 2,
          title: 'Calgary b/w I Can\'t Make You Love Me/Nick Of Time',
          artist: 'Bon Iver',
          song_count: 2
        }
      ]
    });
  }
});

The push() method is also important when working with complex endpoints. You may find your application has an endpoint that performs some business logic then creates several records. This likely does not map cleanly to Ember Data's existing save() API which is structured around persisting a single record. Instead you should make your own custom AJAX request and push the resulting model data into the store so it can be accessed by other parts of your application.

import Ember from 'ember';

export default Ember.Route.extend({
  actions: {
    confirm: function(data) {
      $.ajax({
        data: data,
        method: 'POST',
        url: 'process-payment'
      }).then((digitalInventory) => {
        this.get('store').pushPayload(digitalInventory);
        this.transitionTo('thank-you');
      });
    }
  }
});

Properties that are defined on the model but are omitted in the normalized JSON API document object will not be updated. Properties that are included in the normalized JSON API document object but not defined on the Model will be ignored.