FEATURES.md

About Features

Please read the Feature Flag Guide for a detailed explanation.

Feature Flags

• ember-application-instance-initializers

  Splits apart initializers into two phases:

  • Boot-time Initializers that receive a registry, and use it to set up code structures
  • Instance Initializers that receive an application instance, and use it to set up application state per run of the application.

  In FastBoot, each request will have its own run of the application, and will only need to run the instance initializers.

  In the future, tests will also be able to use this differentiation to run just the instance initializers per-test.

  With this change, App.initializer becomes a "boot-time" initializer, and issues a deprecation warning if instances are accessed.

  Apps should migrate any initializers that require instances to the new App.instanceInitializer API.

• ember-application-initializer-context

  Sets the context of the initializer function to its object instead of the global object.

  Added in #10179.

• ember-testing-checkbox-helpers

  Add check and uncheck test helpers.

  check:

  Checks a checkbox. Ensures the presence of the checked attribute

  Example:

  check('#remember-me').then(function() {
    // assert something
  });

  uncheck:

  Unchecks a checkbox. Ensures the absence of the checked attribute

  Example:

  uncheck('#remember-me').then(function() {
    // assert something
  });

• ember-routing-named-substates

  Add named substates; e.g. when resolving a loading or error substate to enter, Ember will take into account the name of the immediate child route that the error/loading action originated from, e.g. 'foo' if FooRoute, and try and enter foo_error or foo_loading if it exists. This also adds the ability for a top-level application_loading or application_error state to be entered for loading/error events emitted from ApplicationRoute.

  Added in #3655.

• composable-computed-properties

  This feature allows you to combine (compose) different computed properties together. So it gives you a really nice "functional programming" like syntax to deal with complex expressions.

  Added in #3696.

• ember-metal-is-present

  Adds Ember.isPresent as the inverse of Ember.isBlank. This convenience method can lead to more semantic and clearer code.

  Added in #5136

• property-brace-expansion-improvement

  Property brace expansion now allows multiple sets of braces to be used, as well as not restricting their location in the string.

  Added in #4617

• ember-routing-multi-current-when

  Allows the link-to helper's currentWhen property to accept multiple routes using a (space) delimiter, for more control over a link's active state.

  Added in #3673

• ember-routing-fire-activate-deactivate-events

  Fire activate and deactivate events, additionally to the corresponding Ember.Route hooks.

  Added in #5569

• ember-testing-pause-test

  Helper to pause a test, for use in debugging and TDD.

  Added in #9383

• ember-htmlbars-component-generation

  Enables HTMLBars compiler to interpret <x-foo></x-foo> as a component invocation (instead of a standard HTML5 style element).

• ember-htmlbars-inline-if-helper

  Enables the use of the if helper in inline form. The truthy and falsy values are passed as params, instead of using the block form.

  Added in #9718.

• ember-htmlbars-attribute-syntax

  Adds the class="{{color}}" syntax to Ember HTMLBars templates. Works with arbitrary attributes and properties.

  Added in #9721.

• ember-metal-injected-properties

  Enables the injection of properties onto objects coming from a container, and adds the Ember.Service class. Use the Ember.inject.service method to inject services onto any object, or Ember.inject.controller to inject controllers onto any other controller. The first argument to Ember.inject methods is optional, and if left blank the key of the property will be used to perform the lookup instead. Replaces the need for needs in controllers.

  Added in #5162.

• ember-routing-transitioning-classes

  Disables eager URL updates during slow transitions in favor of new CSS classes added to link-tos (in addition to active class):

  • ember-transitioning-in: link-to is not currently active, but will be when the current underway (slow) transition completes.
  • ember-transitioning-out: link-to is currently active, but will no longer be active when the current underway (slow) transition completes.

  Added in #9919

• new-computed-syntax

  Enables the new computed property syntax. In this new syntax, instead of passing a function that acts both as getter and setter for the property, Ember.computed receives an object with get and set keys, each one containing a function.

  For example,

  visible: Ember.computed('visibility', {
    get: function(key) {
      return this.get('visibility') !== 'hidden';
    },
    set: function(key, boolValue) {
      this.set('visibility', boolValue ? 'visible' : 'hidden');
      return boolValue;
    }
  })

  If the object does not contain a set key, the property will simply be overridden. Passing just function is still supported, and is equivalent to passing only a getter.

  Added in #9527.

• ember-metal-stream

  Exposes the basic internal stream implementation as Ember.Stream.

  Added in #9693

• ember-htmlbars-each-with-index

  Adds an optional second parameter to {{each}} block parameters that is the index of the item.

  For example,

  <ul>
    {{#each people as |person index|}}
       <li>{{index}}) {{person.name}}</li>
    {{/each}}
  </ul>

  Added in #10160