title: Emberjs trying to create "radio button" type functionality
body: <p>When a user clicks a model, set <code>isActive:true</code> and set all other models <code>isActive:false</code>. </p>
  
  <p>I have two components and a route involved in trying to achieve this. </p>
  
  <p>Starting at the top I have a <code>distro-item</code> which is a single model item</p>
  
  <pre><code>//components/distro-item
  export default Component.extend({
    classNames: 'column is-2',
    tagName: 'div',
    isActive: false,
  
    actions: {
      toggleActive (distro) {
        this.sendAction('toggleActive', distro);
      }
    }
  
  });
  </code></pre>
  
  <p>I then have a holder component which holds all the <code>distro-item</code>s</p>
  
  <pre><code>// components/distro-holder
  export default Ember.Component.extend({
    sortedDistros: Ember.computed.sort('distros', 'sortDefinition'),
    sortDefinition: ['sortOrder:acs'],
  
    distros: computed('sortedDistros.@each.isActive', function () {
      console.log("triggered");
    }),
  
    actions: {
      toggleActive(distro) {
        this.sendAction('toggleActive', distro);
      }
    }
  
  });
  </code></pre>
  
  <p>Finally the route</p>
  
  <pre><code>//route/new
  export default Route.extend(AuthenticatedRouteMixin, {
  
    selectedDistro: undefined,
  
    model() {
      return RSVP.hash({
        distros: get(this, 'store').findAll('distro'),
      });
    },
  
    setupController(controller, models) {
      controller.setProperties(models);
    },
  
    actions: {
      toggleActive(distro) {
        this.set('selectedDistro', distro);
      },
    }
  
  });
  </code></pre>
  
  <p>I'm not sure which of the three things should be responsible for each part of the processes. initial thinking is the distro-holder should be responsible for figuring out which state each distro should be in, and sending that back to the route. However no matter what I try, I can't get the computed property to trigger. Should this be on the route, or elsewhere? </p>
  
  <p>The <a href="https://guides.emberjs.com/v2.3.0/object-model/computed-properties-and-aggregate-data/" rel="nofollow noreferrer">documentation example</a> seems to have it on the equivalent to the distro-holder. When I change the state of <code>isActive</code> it doesn't fire as I expect...</p>
  
  <p>Any help is appreciated! </p>