Slow Route with loading state

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Randomly Slow Route Demo'
});

controllers.slow-route.js

import Ember from 'ember';

export default Ember.Controller.extend({
});

router.js

import Ember from 'ember';
import config from './config/environment';

const Router = Ember.Router.extend({
  location: 'none',
  rootURL: config.rootURL
});

Router.map(function() {
  this.route('slow-route', {path: '/'});
});

export default Router;

routes.slow-route-loading.js

import Ember from 'ember';

export default Ember.Route.extend({
  actions: {
    refresh() {
      let realController = this.controllerFor('slow-route');

      console.log('REFRESH CALLED IN THE LOADING ROUTE', realController.get('_route'));
      realController.get('_route')._refresh();
    }
  }
});

routes.slow-route.js

import Ember from 'ember';

const API = [
  {
    data: [1, 2, 3],
    responseTime: 5000
  }, {
    data: [100, 200, 300],
    responseTime: 10000
  }, {
    data: [1000, 2000, 3000],
    responseTime: 5000
  }];

export default Ember.Route.extend({
  dataVersion: 0,

  beforeModel(transition) {
    let controller = this.controllerFor(transition.targetName);
    controller.set('_route', this);
    console.log('LOADING STARTED (', transition, ') ');
  },

  model() {
    return new Promise((resolve, reject) => {
      let dataVersion = this.get('dataVersion');
      console.log('REFRESH DATA WITH VERSION', dataVersion, ' (IT WILL TAKE', API[dataVersion].responseTime, 'ms)');

      Ember.run.later(function () {
        let data = API[dataVersion].data;
        console.log('DATA VERSION', dataVersion, 'RETRIEVED: ', data);
        resolve(data);
      }, API[dataVersion].responseTime);
    });
  },

  setupController(controller, model) {
    console.log('SETUP CONTROLLER WITH DATA', model);
    this._super(controller, model);
  },
  
  _refresh() {
    this.set('dataVersion', 1);
    this.refresh();
    Ember.run.later(() => {
      this.set('dataVersion', 2);
      this.refresh();
    }, 100);
  },

  actions: {
    refresh() {
      this._refresh();
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<div>This demo shows how Ember handles (properly) data retrieval concurrency. Here's what you can do:</div>
<ul>
  <li>Load the page - you should see items 1, 2, 3</li>
  <li>Open browser console (in developer tools) to see debugging messages</li>
  <li>Click the Refresh button - you should see items 1000, 2000, 3000 even though obsolete items 100, 200, 300 are retrieved later</li>
  <li>Check the console - you should see that after obsolete data retrieval setupController is not called (which is correct)</li>
</ul>
<button {{action "refresh"}}>Refresh (from TOP level, you can't click twice fast!)</button>
<br>
{{outlet}}
<br>
<br>

templates.slow-route-loading.hbs

Loading...

templates.slow-route.hbs

<button {{action "refresh"}}>Refresh</button>
<hr>
<div>
  <span>Items:</span>
  <ul>
    {{#each content as |item|}}
      <li>{{item}}</li>
    {{/each}}
  </ul>
</div>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}