Ember.js: ArrayController undefined in template - ember.js

Question

Problem:
I am kind of struggling with the organization of my first ember app. The current issue is that the my Items ArrayController is not defined in my dashboard template:
<script type="text/x-handlebars" data-template-name="dashboard">
{{#if controllers.items}}
<p class="alert alert-error">Dashboard can access item's info - Nice!</p>
{{else}}
<p class="alert alert-error">Dashboard cannot access items... :-/</p>
{{/if}}
</script>
Likely cause: *
**EDIT: after talking with #conrad below, I'm kind of questioning this:*
I had a similar issue in an earlier post and kingpin2k suggested the cause was that I:
"never created anything that uses the options controller".
This is probably the case here as well. This quick screencast shows that a breakpoint on my ArrayController is not hit on page load - but it is hit when I inspect the Items controller in the Ember inspector tool (eg, Ember creates the ArrayController object right then for the first time).
Apparent non-solutions:
My Dashboard controller says it needs the Items controller. I guess that isn't enough to instantiate the ArrayController?
App.ItemsController = Ember.ArrayController.extend({
len: function(){
return this.get('length');
}.property('length'),
totalCost: function() {
return this.reduce( function(prevCost, item){
return parseInt(item.get('values').findBy('type', 'cost').price, 10) + prevCost;
}, 0);
}.property('#each.values')
[more computed properties...]
});
App.DashboardController = Em.Controller.extend({
needs: ['items'],
itemsLength: Ember.computed.alias('controllers.items.len'),
itemsTotalCost: Ember.computed.alias('controllers.items.totalCost'),
[more computed properties...]
});
Furthermore, each item in Items is being rendered in my items template. I guess that does not create the missing controllers.items either...
<script type="text/x-handlebars" data-template-name="items">
{{#each}}
[these render fine]
{{/each}}
</script>
<script type="text/x-handlebars" data-template-name="display">
<!-- DISPLAY TEMPLATE -->
{{!- DASHBOARD -}}
{{render dashboard}}
{{!- ITEMS -}}
{{render 'items' items}}
</script>
So then.. what?
I can imagine many possible avenues, but haven't gotten any of them to work yet:
Specify the Items ArrayController in {{render dashboard}}?
Some configuration in a Route?
Maybe my templates/routes are not correctly arranged?

Answer 1

You could make sure that the ItemController is instantiated in the dashboard template by calling it in the DashboardController's init function:
App.DashboardController = Em.Controller.extend({
needs: ['items'],
init: function() {
this._super();
this.get('controllers.items.length');
}
});
/edit:
removed the part that was not helpful