Computed Properties and Aggregate Data
Sometimes you have a computed property whose value depends on the properties of items in an array. For example, you may have an array of todo items, and want to calculate the incomplete todo's based on their isDone property.
To facilitate this, Ember provides the @each key illustrated below:
app/components/todo-list.js
export default Ember.Component.extend({
todos: null,
init() {
this.set('todos', [
Ember.Object.create({ isDone: true }),