Class Evented

public

Defined in: packages/@ember/-internals/runtime/lib/mixins/evented.js:13

import Evented from '@ember/object/evented';

This mixin allows for Ember objects to subscribe to and emit events.

app/utils/person.js

import EmberObject from '@ember/object';
import Evented from '@ember/object/evented';

export default EmberObject.extend(Evented, {
  greet() {
    // ...
    this.trigger('greet');
  }
});

var person = Person.create();

person.on('greet', function() {
  console.log('Our person has greeted');
});

person.greet();

// outputs: 'Our person has greeted'

You can also chain multiple event subscriptions:

person.on('greet', function() {
  console.log('Our person has greeted');
}).one('greet', function() {
  console.log('Offer one-time special');
}).off('event', this, forgetThis);

Show: Inherited Protected Private Deprecated

has (name) Boolean public

Module: @ember/object

Defined in packages/@ember/-internals/runtime/lib/mixins/evented.js:139

name: String; The name of the event
returns: Boolean; does the object have a subscription for event

Checks to see if object has any subscriptions for named event.

off (name, target, method) public

Module: @ember/object

Defined in packages/@ember/-internals/runtime/lib/mixins/evented.js:124

name: String; The name of the event
target: Object; The target of the subscription
method: Function|String; The function or the name of a function of the subscription
returns: this

Cancels subscription for given name, target, and method.

on (name, target, method) public

Module: @ember/object

Defined in packages/@ember/-internals/runtime/lib/mixins/evented.js:54

name: String; The name of the event
target: Object; The "this" binding for the callback
method: Function|String; A function or the name of a function to be called on target
returns: this

Subscribes to a named event with given function.

person.on('didLoad', function() {
  // fired once the person has loaded
});

An optional target can be passed in as the 2nd argument that will be set as the "this" for the callback. This is a good way to give your function access to the object triggering the event. When the target parameter is used the callback method becomes the third argument.

one (name, target, method) public

Module: @ember/object

Defined in packages/@ember/-internals/runtime/lib/mixins/evented.js:80

name: String; The name of the event
target: Object; The "this" binding for the callback
method: Function|String; A function or the name of a function to be called on target
returns: this

Subscribes a function to a named event and then cancels the subscription after the first time the event is triggered. It is good to use one when you only care about the first time an event has taken place.

This function takes an optional 2nd argument that will become the "this" value for the callback. When the target parameter is used the callback method becomes the third argument.

trigger (name, args) public

Module: @ember/object

Defined in packages/@ember/-internals/runtime/lib/mixins/evented.js:101

name: String; The name of the event
args: Object...; Optional arguments to pass on

Triggers a named event for the object. Any additional arguments will be passed as parameters to the functions that are subscribed to the event.

person.on('didEat', function(food) {
  console.log('person ate some ' + food);
});

person.trigger('didEat', 'broccoli');

// outputs: person ate some broccoli