Declare and enforce your Ember Component's attributes and their types
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ember-strong-attrs is an addon that facilitates the declaration of Ember.Component required and optional attributes. It extends Ember.Component and provides two APIs to declare required and optional attributes. One is an ES6 compatible API, the other is an ES7 decorators based API.

Build Status


  • Experimental. This is alpha software, and we think it's a cool idea but not sure if it's a good idea yet.
  • If you are are using the ES7 Decorators API:
    • You need to enable ES7 Decorators in Babel.
    • JSHint does not support ES7 Decorators at the moment so you will get JSHint errors like this: Unexpected '@'.. To avoid this, you can tell jshint to ignore your decorators for now, as shown in the examples below.
    • Your Ember.Components need to be ES6 classes so that the ES7 Decorators can decorate them.


  1. Install the addon
ember install ember-strong-attrs
  1. For ES7 Decorators API
  2. Update your ember-cli-build.js to enable Babel's ES7 Decorators
/* global require, module */
var EmberApp = require('ember-cli/lib/broccoli/ember-app');

module.exports = function(defaults) {
  defaults.babel = {
    optional: ['es7.decorators']

  var app = new EmberApp(defaults, {});

  return app.toTree();
  1. Update the components you want to declare required/option attributes on to use ES6 Classes syntax.
Given the following `Ember.Component` definition:

import Ember from 'ember';

export default Ember.Component.extend({
  // ... your methods and props

You will get the following using [ES6 Classes syntax][classes]

import Ember from 'ember';

export default class extends Ember.Component.extend({ // Note the class keyword
  // ... your methods and props
}) { } // Don't forget the trailing { } and the removal of the semicolon
  1. Import the decorator/function into your component file.
// For ES7 Decorators
import { requiredAttr, optionalAttr } from 'ember-strong-attrs';


// ES6 API
import { declareStrongAttrs } from 'ember-strong-attrs';


Supported Attribute types

The attrType argument can be the following classes:

Note that attrType is an optional argument.

  • String
  • Number
  • Date
  • Function
  • YouCustomClass


ember-strong-attr exposes one function to declare strong attributes on Ember.Component

  • declareStrongAttrs(attrsFunc, component), which modifies and then returns the modified component that was passed in.
  • The attrsFunc function is given two methods for declaring attributes. They both accessible via that function's this object:
    • this.requiredAttr(attrName[, attrType])
    • this.optionalAttr(attrName[, attrType])


import Ember from 'ember';
import { declareStrongAttrs } from 'ember-strong-attrs';
import Person from '../models/person';

export default declareStrongAttrs(function() {
  this.requiredAttr('myRequiredAttr', String);
  this.optionalAttr('myOptionalAttr', String);
  this.requiredAttr('myPersonAttr', Person);
}, Ember.Component.extend({
  // ... your methods and props

ES7 Decorators API

ember-strong-attrs exposes two decorators:

  • @requiredAttr(attrName[, attrType])
  • @optionalAttr(attrName[, attrType])


import Ember from 'ember';
import { requiredAttr, optionalAttr } from 'ember-strong-attrs';
import Person from '../models/person';

// Note the lack of semicolons behind the decorators
/* jshint ignore: start */
@requiredAttr('myRequiredAttr', String)
@optionalAttr('myStringAttr', String)
@optionalAttr('myPersonAttr', Person)
/* jshint ignore: end */
export default class extends Ember.Component.extend({
  // ... your methods and props
}) { }