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Deprecation Guide for new EmberObject

until: 3.9.0
id: object.new-constructor

We are deprecating usage of new EmberObject() to construct instances of EmberObject and it's subclasses. This affects all classes that extend from EmberObject as well, including user defined classes and Ember classes such as:

  • Component
  • Controller
  • Service
  • Route
  • Model

Instead, you should use EmberObject.create() to create new instances of classes that extend from EmberObject. If you are using native class syntax instead of EmberObject.extend() to define your classes, you can also refactor to not extend from EmberObject, and continue to use new syntax.

Refactoring to use create() instead of new

Before this deprecation, new EmberObject() and EmberObject.create() were functionally the same, with one difference - new EmberObject() could only receive 1 argument, whereas EmberObject.create() could receive several. Because new was strictly less powerful, you can safely refactor existing code to call create with the same arguments as before:


let obj1 = new EmberObject();
let obj2 = new EmberObject({ prop: 'value' });

const Foo = EmberObject.extend();
let foo = new Foo({ bar: 123 });


let obj1 = EmberObject.create();
let obj2 = EmberObject.create({ prop: 'value' });

const Foo = EmberObject.extend();
let foo = Foo.create({ bar: 123 })

Refactoring native classes to not extend from EmberObject

If you are using native class syntax to extend from EmberObject, you can instead define your classes without a base class. This means that you will have to write your own constructor function:


class Person extends EmberObject {}

let rwjblue = new Person({ firstName: 'Rob', lastName: 'Jackson' });


class Person {
  constructor(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;

let rwjblue = new Person('Rob', 'Jackson');

This is closer to the way native classes are meant to work, and can help with low level performance concerns such as shaping. It also enforces clear interfaces which can help define the purpose of a class more transparently.