javascript - View controller needs: property not working -

i have view, attach controller via controller: on create , want require controller i'd using needs:. when add i'm getting error "uncaught typeerror: cannot call method 'has' of null"

templates:

<script type="text/x-handlebars" charset="utf-8">     <div id="viewport">         {{view app.playerview}}         {{controllers.currentuser.content.name}}     </div> </script>  <script type="text/x-handlebars" data-template-name="player" charset="utf-8">     <button {{action play on="click"}}>play</button> </script> 

js:

app = ember.application.create();     app.user = ember.object.extend({     name:'john' });  app.applicationroute = ember.route.extend({     setupcontroller: function() {         this.controllerfor('currentuser').set('content', app.user.create({ name:'jose' }));     } });  //controllers app.applicationcontroller = ember.controller.extend({     needs:['currentuser'] });  app.currentusercontroller = ember.controller.extend();  app.playercontroller = ember.controller.extend({     isplaying: false,     //needs:['currentuser'], //uncomment break!!     play: function() {         this.toggleproperty('isplaying');         alert(this.get('isplaying'));     } });  //views app.playerview = ember.view.extend({     templatename:'player',     tagname: 'footer' });  app.playerview = app.playerview.create({     classnamebindings: ['controller.isplaying:playing'],     controller: app.playercontroller.create() }) 

i've set fiddle here: http://jsfiddle.net/84f9n/ (just uncomment line in playercontroller)

updated jsfiddle

you can use {{render}} helper render view/controller.

from docs:

{{render}} several things:

• gets singleton instance of corresponding controller renders
• the named template using controller sets model of the
• corresponding controller

for example, change {{view ... }} helper use {{render}} instead:

{{render "player"}} 

this find playerview , playercontroller , use them, similar route, without actual routing part.