Class CoreObject


CoreObject is the base class for all Ember constructs. It establishes a class system based on Ember's Mixin system, and provides the basis for the Ember Object Model. CoreObject should generally not be used directly, instead you should use EmberObject.


You can define a class by extending from CoreObject using the extend method:

const Person = CoreObject.extend({
  name: 'Tomster',

For detailed usage, see the Object Model section of the guides.

Usage with Native Classes

Native JavaScript class syntax can be used to extend from any CoreObject based class:

class Person extends CoreObject {
  init() {
    super.init(...arguments); = 'Tomster';

Some notes about class usage:

  • new syntax is not currently supported with classes that extend from EmberObject or CoreObject. You must continue to use the create method when making new instances of classes, even if they are defined using native class syntax. If you want to use new syntax, consider creating classes which do not extend from EmberObject or CoreObject. Ember features, such as computed properties and decorators, will still work with base-less classes.
  • Instead of using this._super(), you must use standard super syntax in native classes. See the MDN docs on classes for more details.
  • Native classes support using constructors to set up newly-created instances. Ember uses these to, among other things, support features that need to retrieve other entities by name, like Service injection and getOwner. To ensure your custom instance setup logic takes place after this important work is done, avoid using the constructor in favor of init.
  • Properties passed to create will be available on the instance by the time init runs, so any code that requires these values should work at that time.
  • Using native classes, and switching back to the old Ember Object model is fully supported.




Destroys an object by setting the isDestroyed flag and removing its metadata, which effectively destroys observers and bindings.

If you try to set a property on a destroyed object, an exception will be raised.

Note that destruction is scheduled for the end of the run loop and does not happen immediately. It will set an isDestroying flag immediately.

An overridable method called when objects are instantiated. By default, does nothing unless it is overridden during class definition.


import EmberObject from '@ember/object';

const Person = EmberObject.extend({
  init() {
    alert(`Name is ${this.get('name')}`);

let steve = Person.create({
  name: 'Steve'

// alerts 'Name is Steve'.

NOTE: If you do override init for a framework class like Component from @ember/component, be sure to call this._super(...arguments) in your init declaration! If you don't, Ember may not have an opportunity to do important setup work, and you'll see strange behavior in your application.


string representation

Returns a string representation which attempts to provide more information than Javascript's toString typically does, in a generic way for all Ember objects.

import EmberObject from '@ember/object';

const Person = EmberObject.extend();
person = Person.create();
person.toString(); //=> "<Person:ember1024>"

If the object's class is not defined on an Ember namespace, it will indicate it is a subclass of the registered superclass:

const Student = Person.extend();
let student = Student.create();
student.toString(); //=> "<(subclass of Person):ember1025>"

If the method toStringExtension is defined, its return value will be included in the output.

const Teacher = Person.extend({
  toStringExtension() {
    return this.get('fullName');
teacher = Teacher.create();
teacher.toString(); //=> "<Teacher:ember1026:Tom Dale>"

Override to implement teardown.