Creating, Updating and Deleting

Creating, Updating and Deleting

Creating Records

You can create records by calling the createRecord() method on the store.

store.createRecord('post', {
  title: 'Rails is Omakase',
  body: 'Lorem ipsum'
});

The store object is available in controllers and routes using this.get('store').

Updating Records

Making changes to Ember Data records is as simple as setting the attribute you want to change:

this.get('store').findRecord('person', 1).then(function(tyrion) {
  // ...after the record has loaded
  tyrion.set('firstName', "Yollo");
});

All of the Ember.js conveniences are available for modifying attributes. For example, you can use Ember.Object's incrementProperty helper:

person.incrementProperty('age'); // Happy birthday!

Persisting Records

Records in Ember Data are persisted on a per-instance basis. Call save() on any instance of DS.Model and it will make a network request.

Ember Data takes care of tracking the state of each record for you. This allows Ember Data to treat newly created records differently from existing records when saving.

By default, Ember Data will POST newly created records to their type url.

var post = store.createRecord('post', {
  title: 'Rails is Omakase',
  body: 'Lorem ipsum'
});

post.save(); // => POST to '/posts'

Records that already exist on the backend are updated using the HTTP PATCH verb.

store.findRecord('post', 1).then(function(post) {
  post.get('title'); // => "Rails is Omakase"

  post.set('title', 'A new post');

  post.save(); // => PATCH to '/posts/1'
});

You can tell if a record has outstanding changes that have not yet been saved by checking its hasDirtyAttributes property. You can also see what parts of the record were changed and what the original value was using the changedAttributes() method. changedAttributes returns an object, whose keys are the changed properties and values are an array of values [oldValue, newValue].

person.get('isAdmin');            //=> false
person.get('hasDirtyAttributes'); //=> false
person.set('isAdmin', true);
person.get('hasDirtyAttributes'); //=> true
person.changedAttributes();       //=> { isAdmin: [false, true] }

At this point, you can either persist your changes via save() or you can roll back your changes. Calling rollbackAttributes() for a saved record reverts all the changedAttributes to their original value. If the record isNew it will be removed from the store.

person.get('hasDirtyAttributes'); //=> true
person.changedAttributes();       //=> { isAdmin: [false, true] }

person.rollbackAttributes();

person.get('hasDirtyAttributes'); //=> false
person.get('isAdmin');            //=> false
person.changedAttributes();       //=> {}

Handling Validation Errors

If the backend server returns validation errors after trying to save, they will be available on the errors property of your model. Here's how you might display the errors from saving a blog post in your template:

{{#each post.errors.title as |error|}}
  <div class="error">{{error.message}}</div>
{{/each}}
{{#each post.errors.body as |error|}}
  <div class="error">{{error.message}}</div>
{{/each}}

Promises

save() returns a promise, which makes easy to asynchronously handle success and failure scenarios. Here's a common pattern:

var post = store.createRecord('post', {
  title: 'Rails is Omakase',
  body: 'Lorem ipsum'
});

var self = this;

function transitionToPost(post) {
  self.transitionToRoute('posts.show', post);
}

function failure(reason) {
  // handle the error
}

post.save().then(transitionToPost).catch(failure);

// => POST to '/posts'
// => transitioning to posts.show route

Deleting Records

Deleting records is as straightforward as creating records. Call deleteRecord() on any instance of DS.Model. This flags the record as isDeleted. The deletion can then be persisted using save(). Alternatively, you can use the destroyRecord method to delete and persist at the same time.

store.findRecord('post', 1, { backgroundReload: false }).then(function(post) {
  post.deleteRecord();
  post.get('isDeleted'); // => true
  post.save(); // => DELETE to /posts/1
});

// OR
store.findRecord('post', 2, { backgroundReload: false }).then(function(post) {
  post.destroyRecord(); // => DELETE to /posts/2
});

The backgroundReload option is used to prevent the fetching of the destroyed record, since findRecord() automatically schedules a fetch of the record from the adapter.