Cancelable prefetch - v2

controllers.application.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('parent', function() {
    this.route('child');
  });
});

export default Router;

routes.parent.child.js

import Ember from 'ember';
import prefetchUtil from '../../utils/prefetch';

export default Ember.Route.extend({
  prefetch() {
    return this.prefetched('parent').then((response) => {
      // must check response for cancelation
      if (prefetchUtil.isPrefetchCanceled(response)) {
        return response;
      }

      return Ember.RSVP.resolve(Ember.assign({}, response, {
        completeMsg: 'We made it!'
      }));
    });
  }
});

routes.parent.js

import Ember from 'ember';
import prefetchUtil from '../utils/prefetch';

export default Ember.Route.extend({
  queryParams: {
    cancel: { refreshModel: true }
  },

  prefetch(params) {
    // Using query params to cancel here for demo purposes
    // In app this would be a check if user needs to be reauthenticated
    if (params.queryParams.cancel) {
      // In app we would also transition to login
      // or to loading screen in case of external SSO
      return prefetchUtil.cancelPrefetch({
        statusMsg: 'Canceled'
      });
    }

    return Ember.RSVP.resolve({
      statusMsg: 'Not Canceled'
    });
  }
});

templates.application.hbs

<h3>Cancelable prefetch</h3>
<p>In <em>routes/parent</em> we may decide to cancel the prefetch. In <em>routes/child</em> we check if the parent prefetch has been canceled.</p>
<p>Some prefetch helper functions can be found in <em>utils/prefetch</em>.</p>
<br>
<p>{{#link-to "parent.child" (query-params cancel=true)}}Visit route - cancel{{/link-to}}</p>
<p>{{#link-to "parent.child"  (query-params cancel=undefined)}}Visit route - success{{/link-to}}</p>
<br>
<br>
{{outlet}}
<br>

templates.parent.child.hbs

<p>Prefetch status: <b>{{model.statusMsg}}</b></p>
<p>{{model.completeMsg}}</p>

templates.parent.hbs

{{outlet}}

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",
    "ember-prefetch": "2.1.6"
  }
}

utils.prefetch.js

export function isPrefetchCanceled(data) {
  return data.isPrefetchCanceled;
};
  
export function cancelPrefetch(data) {
  return Ember.assign({}, data, {
    isPrefetchCanceled: true
  });
};