Ember 3.11 Released

– By Kenneth Larsen

Today the Ember project is releasing version 3.11 of Ember.js, Ember Data, and Ember CLI. This release kicks off the 3.12 beta cycle for all sub-projects. We encourage our community (especially addon authors) to help test these beta builds and report any bugs before they are published as a final release in six weeks' time. The ember-try addon is a great way to continuously test your projects against the latest Ember releases.

You can read more about our general release process here:


Ember.js is the core framework for building ambitious web applications.

Changes in Ember.js 3.11

Ember.js 3.11 is an incremental, backwards compatible release of Ember with bugfixes, performance improvements, and minor deprecations. There are four (4) new features, one (1) deprecation, and several bugfixes in this version.

New Features (4)

Forwarding Element Modifiers with ...attributes (1 of 4)

Angle bracket component invocation was introduced in Ember.js 3.4. Aside from the syntatic differences, the angle bracket invocation syntax enabled passing HTML attributes to components, which can then be applied the underlying HTML element(s) in the component's layout using the ...attributes syntax. This is also known informally as the "splattributes" feature.

This features clarifies how the "splattributes" feature interact with element modifiers.

For more information please refer to the RFC.

The {{fn}} helper (2 of 4)

The {{fn}} helper provides a way to pass arguments to actions.

The action method creates an action from a function so that it can be passed to event handlers in templates. It ensures that the this value in the countUp action will always be the component instance, which allows it to be freely passed to other components. Where this falls short is when we need to pass arguments to these actions.

import Component from "@ember/component";
import { action } from '@ember/object';

export default Component.extend({
  count: 0,

  countUp: action(function() {
Current count: {{this.count}}

<MyButton @click={{this.countUp}}>Add One</MyButton>

The {{fn}} helper provides a way to pass arguments into actions and "bundle" them up, so that they can be passed around to other components and still retain the provided arguments when called:

Current count: {{this.count}}

{{!-- when not passing arguments, these are equivalent --}}
<MyButton @click={{this.countUp}}>Add One</MyButton>
<MyButton @click={{fn this.countUp}}>Add One</MyButton>

{{!-- calls this.countUp(10) when clicked --}}
<MyButton @click={{fn this.countUp 10}}>Add Ten</MyButton>

In addition to the basic use case shown here, the {{fn}} helper supports other advanced use cases, such as adding more arguments to an existing function.

{{#let (fn this.log "hello") as |hello|}}
  {{!-- calls this.log("hello", "world") --}}
  <MyButton @click={{fn hello "world"}}>
    Hello World

  {{!-- calls this.log("hello", "Tomster", "Zoey") --}}
  <MyButton @click={{fn hello "Tomster" "Zoey"}}>
    Hello Tomster and Zoey

It should also be noted that the {{action}} helper can previously be used to accomplish similar functionalities, but due to some historical decisions, it may produce surprising results in some cases. Therefore, Ember users are encouraged to migrate to the {{fn}} helper along with the action method where possible and appropriate. Refer to the RFC for more details and examples.

The {{on}} modifier (3 of 4)

The {{on}} modifier provides a straightforward way to listen to DOM events on arbitrary elements.

import Component from "@ember/component";
import { action } from '@ember/object';

export default Component.extend({
  count: 0,

  countUp: action(function() {
Current count: {{this.count}}

<button {{on "click" this.countUp passive=true}}>Add One</button>

The {{on}} modifier in this example attaches a passive "click" event listener on the button, such that when the button is clicked, the countUp action will be called. Like before, wrapping our function in an action call ensures the countUp action will have the right this value at runtime.

By default, the action passed to the {{on}} modifier will receive the DOM event as an argument. The fn helper can be used in conjunction with the {{on}} modifier to alter this behavior. Along with the "Splattributes" feature mentioned above, the {{on}} modifier can also be applied to component elements as well.

Finally, it should be noted that the {{action}} modifier, and in some cases, DOM properties like onclick= could previously be used to accomplish similar functionalities. However, both of these approaches have their own drawbacks. Therefore, Ember users are encouraged to migrate to the {{on}} modifier along with the action method where possible and appropriate. See the RFC for more details and examples.

Inject Parameter Normalization (4 of 4)

Inject Parameter Normalization normalizes this contract for all Ember base classes - that is, framework classes that are provided by Ember:

  • GlimmerComponent
  • EmberComponent
  • Service
  • Route
  • Controller
  • Helper

Along with framework clases provided by Ember Data:

  • Model
  • Adapter
  • Serializer
  • Transform

For more info please refer to the RFC.

Deprecations (1)

Deprecations are added to Ember.js when an API will be removed at a later date. Each deprecation has an entry in the deprecation guide describing the migration path to a more stable API. Deprecated public APIs are not removed until a major release of the framework.

Consider using the ember-cli-deprecation-workflow addon if you would like to upgrade your application without immediately addressing deprecations.

For more details on changes in Ember.js 3.11, please review the Ember.js 3.11.0 release page.

Deprecate Function.prototype.observes (1 of 1)

Historically, Ember has extended the Function.prototype with a few functions (on, observes, property), over time we have moved away from using these prototype extended functions in favor of using the official ES modules based API.

Please refer to the deprecation guides for information on how to migrate away from Function.prototype.

Ember Data

Ember Data is the official data persistence library for Ember.js applications.

Important note about Ember Data 3.11

There is a known bug in 3.11.0 which means ember generate model something doesn't work. We are currently working a patch for this. Likewise there is a known bug for displaying the 3.11 API documentation on api.emberjs.com, which will also be fixed in a patch. This blog post will be updated once these issues are resolved.

Changes in Ember Data 3.11

New Features (1)

Packages feature (1 of 1)

In addition to several bug fixes and small documentation fixes, this release is the first release that ships ember-data as a collection of smaller packages. Over time, some of these packages will become optional.

The packages feature also introduces a new import syntax.


import Model from 'ember-data/model';
import attr from 'ember-data/attr';
import { belongsTo, hasMany } from 'ember-data/relationships';


import DS from 'ember-data';

const { Model, attr, belongsTo, hasMany } = DS;

Can now be achieved like this:

import Model, { attr, belongsTo, hasMany } from '@ember-data/model';

With the landing of this feature, the previous import styles will become deprecated in an upcoming release. Lint rules and a codemod will be available before that time to ensure a seamless transition to the new syntax.

You can read more about the new package syntax in the RFC

Deprecations (0)

No new deprecations introduced in Ember Data 3.11.

For more details on changes in Ember Data 3.11, please review the Ember Data 3.11.0 release page.

Ember CLI

Ember CLI is the command line interface for managing and packaging Ember.js applications.

Upgrading Ember CLI

You may upgrade Ember CLI using the ember-cli-update project:

npm install -g ember-cli-update

This utility will help you to update your app or add-on to the latest Ember CLI version. You will probably encounter merge conflicts, in which the default behavior is to let you resolve conflicts on your own. For more information on the ember-cli-update project, see the github README.

While it is recommended to keep Ember CLI versions in sync with Ember and Ember Data, this is not required. After updating ember-cli, you can keep your current version(s) of Ember or Ember Data by editing package.json to revert the changes to the lines containing ember-source and ember-data.

Changes in Ember CLI 3.11

Ember CLI 3.11 contains several bug fixes. Have a look at the complete changelog for an overview.

New Features (0)

No new features in Ember CLI 3.11.

Deprecations (0)

No new deprecations in Ember CLI 3.11.

For more details on the changes in Ember CLI 3.11 and detailed upgrade instructions, please review the Ember CLI 3.11.0 release page.

Thank You!

As a community-driven open-source project with an ambitious scope, each of these releases serve as a reminder that the Ember project would not have been possible without your continued support. We are extremely grateful to our contributors for their efforts.