async

adapters.application.js

import DS from 'ember-data';
export default DS.RESTAdapter;

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions: {
    click() {
      this.sendAction('action', this.get('model'));
    }
  }
});

helpers.eq.js

import Ember from 'ember';

export function eq(params/*, hash*/) {
  return Ember.isEqual(params[0], params[1]);
}

export default Ember.Helper.helper(eq);

models.child-model.js

import DS from 'ember-data';

export default DS.Model;

models.parent-model.js

import DS from 'ember-data';

export default DS.Model.extend({
  child: DS.belongsTo('child-model', {async: true})
});

routes.index.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    return {
      child: this.store.createRecord('child-model'),
      parent: this.store.createRecord('parent-model')
    }
  },
  actions: {
    click(child) {
      var model = this.modelFor('index');
      this.set('controller.clicked', true);
      model.parent.set('child', child);
    }
  }
});

templates.components.my-component.hbs

<button {{action (action "click")}}>Click me</button>
{{yield}}

templates.index.hbs

{{my-component
  model=model.child
  action="click"
}}
<br>

{{#if clicked}}
  {{#if (eq model.parent.child model.child)}}
    It worked
  {{else}}
    It didn't work
  {{/if}}

  <br>
  <br>
  To be selected: {{model.child}}
  <br>
  Selected: {{model.parent.child}}
{{/if}}

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "1.13.13",
    "ember-data": "1.13.15",
    "ember-template-compiler": "1.13.13"
  }
}