observer bracket expansion

controllers.application.js

import Ember from 'ember';


export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  titles: Ember.computed('model.@each.{title}', function() {
    return this.get('model').mapBy('title');
  }),
  setByObserver: [],
  setByObserverWithoutBracketExpansion: [],
  actions: {
    changeTitle() {
      this.addObserver('model.@each.{title}', function() {
        this.set('setByObserver', this.get('model').mapBy('title'));
      });
      
      this.addObserver('model.@each.title', function() {
        this.set('setByObserverWithoutBracketExpansion', this.get('model').mapBy('title'));
      });
      
      this.get('model.firstObject').set('title', 'foo');
    }
  }
});

models.book.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  title: DS.attr('string')
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    return [this.store.createRecord('book', { title: 'Great Gatsby' })];
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
#each titles:
{{#each model as |book|}}
{{book.title}}
{{/each}}
<br>
computed titles:
{{#each titles as |title|}}
{{title}}
{{/each}}
<br>
setByObserver with bracket expansion titles:
{{#each setByObserver as |title|}}
{{title}}
{{/each}}
<br>
setByObserver without bracket expansion titles:
{{#each setByObserverWithoutBracketExpansion as |title|}}
{{title}}
{{/each}}
<br>
<br>
<button {{action 'changeTitle'}}>change</button>

twiddle.json

{
  "version": "0.8.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}