never un-render

components.rich-and-complex.js

import Ember from 'ember';

export default Ember.Component.extend({
  
  classNames: ['rich-and-complex']
  
});

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() {
  
  // rich & complex model
  this.route('heavy-dom', {path: '/heavy-dom/:rc_model'}, function() {
    // guest model
    this.route('guest', {path: '/guest/:g_model'});
    this.route('expensive-a');
    this.route('expensive-b');
  });
  
  this.route('just-a-page');
  
});

export default Router;

routes.application.js

import Ember from 'ember';

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

routes.heavy-dom.expensive-a.js

import Ember from 'ember';

export default Ember.Route.extend({
  
  model() {
    const model = {
      name: 'A',
    };
 
    this.transitionTo('heavy-dom', model);
  },

});

routes.heavy-dom.expensive-b.js

import Ember from 'ember';

export default Ember.Route.extend({
  
  model() {
    return 'B';
  }
  
});

routes.heavy-dom.guest.js

import Ember from 'ember';

export default Ember.Route.extend({
  
  //renderTemplate docs:
  //https://emberjs.com/api/ember/2.16/classes/Route/methods/renderTemplate?anchor=renderTemplate
  renderTemplate(controller, model) {
    this._super(...arguments);
 
    if (!model._templateName) {
      return;
    }
        
    //render docs:   
    //https://emberjs.com/api/ember/2.16/classes/Route/methods/render?anchor=render
    this.render(model._templateName, {
      model: model,
    });
  },
  
  //TODO: this hook is executed twice :(
  serialize(model) {
    console.info('serialize /heavy-dom/guest/');
    console.info(model);
    
    //NOTE:
    //results in a URL that is useless to share
    return {
      g_model: 'g_model'
    };
  },
  
});

routes.heavy-dom.js

import Ember from 'ember';

export default Ember.Route.extend({
  
  //TODO: this hook is executed twice :(
  serialize(model) {
    console.info('serialize /heavy-dom');
    console.info(model);
    
    //NOTE:
    //results in a URL that is useless to share
    return {
      rc_model: 'rc_model'
    };
  },
  
});

routes.index.js

import Ember from 'ember';

export default Ember.Route.extend({
  
  redirect() {
    this.transitionTo('just-a-page');
  }
  
});

routes.just-a-page.js

import Ember from 'ember';

export default Ember.Route.extend({
  
  model() {
    const hostModel = Promise.resolve({
      _templateName: 'just-a-page',
      title: "just a title",
    });
    
    const heavyDomModel = null;
    
    this.transitionTo('heavy-dom.guest', heavyDomModel, hostModel);
  },
  
}); 

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.rich-and-complex {
  border-radius: 4px;
  background-color: #f3b500;
  border: 1px solid yellow;
  padding: 7px;
  width: 300px;
  height: 100px;
  text-align: center;
}

templates.application.hbs

{{link-to "Home" "just-a-page"}}
{{link-to "Heavy A" "heavy-dom.expensive-a"}}
{{link-to "Heavy B" "heavy-dom.expensive-b"}}
{{link-to "Guest" "heavy-dom.guest" "dummy"}}

<br><br>

{{outlet}}

templates.components.rich-and-complex.hbs

~{{name}}~

templates.heavy-dom.expensive-a.hbs

expensive-a.hbs

templates.heavy-dom.expensive-b.hbs

expensive-b.hbs

templates.heavy-dom.guest.hbs

heavy-dom/guest.hbs
<br>
{{model}}
<br>
<b>never be rendered</b>, if you don't link to it of course

templates.heavy-dom.hbs

<div id="wrapper-for-debug-purposes-only">
  {{rich-and-complex name=model.name}}
</div>

{{outlet}}

templates.index.hbs

index.hbs

templates.just-a-page.hbs

<h5>{{model.title}}</h5>

Click the links to render a rich, complex & flavorful component.

tests.helpers.destroy-app.js

import Ember from 'ember';

export default function destroyApp(application) {
  Ember.run(application, 'destroy');
}

tests.helpers.resolver.js

import Resolver from '../../resolver';
import config from '../../config/environment';

const resolver = Resolver.create();

resolver.namespace = {
  modulePrefix: config.modulePrefix,
  podModulePrefix: config.podModulePrefix
};

export default resolver;

tests.helpers.start-app.js

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

const { run } = Ember;
const assign = Ember.assign || Ember.merge;

export default function startApp(attrs) {
  let application;

  let attributes = assign({rootElement: "#test-root"}, config.APP);
  attributes = assign(attributes, attrs); // use defaults, but you can override;

  run(() => {
    application = Application.create(attributes);
    application.setupForTesting();
    application.injectTestHelpers();
  });

  return application;
}

tests.test-helper.js

import resolver from './helpers/resolver';
import {
  setResolver
} from 'ember-qunit';

setResolver(resolver);

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": "2.4.5",
    "ember-template-compiler": "2.4.5",
    "ember-testing": "2.4.5"
  },
  "addons": {}
}