addon/components/md-collection.js
import Component from '@ember/component';
import { bool } from '@ember/object/computed';
import layout from '../templates/components/md-collection';
export default Component.extend({
layout,
classNames: ['collection'],
classNameBindings: ['_hasHeader:with-header'],
headerComponentName: 'md-default-collection-header',
header: null,
_hasHeader: bool('header')
});