How do you pass the index of iteration of {{#each}}? - ember.js

Question

I have a grid of objects to display. Each row of the grid displays 4 objects. Depending on where an object is in the grid I want certain classes to be on the elements of the objects. For example the last object in the grid should have the class "last_in_grid". This calculation depends on the index of the object in an array.
My template looks like:
{{#each row in objects}}
{{#each object in row}}
{{view MyApp.MyView objectBinding="object"}}
{{/each}}
{{/each}}
MyApp.MyView needs to know the index in of iteration of the each helper.
Ideally I want something like:
{{#each row in objects}}
{{#each object in row}}
{{view MyApp.MyView objectBinding="object" indexBinding="index_of_each_loop"}}
{{/each}}
{{/each}}
Django's template language can do this:
{% for item in items %}
{% if forloop.counter0 == 0 %}
blah blah blah
{% endif %}
{% endfor %}
https://docs.djangoproject.com/en/1.4/ref/templates/builtins/#for
Is this possible using Ember and Handlebars?
Do I have to write a custom version of each to do this?

Answer 1

Instead of {{each}} helper, You can use {{collection}} helper to get current index of iteration like this Fiddle:
http://jsfiddle.net/secretlm/67GQb/73/
HTML:
{{#collection contentBinding="App.peopleController"}}
{{#view App.PersonView personBinding="content" indexParentBinding="contentIndex" }}
<td>{{indexParent}}</td>
<td>{{person.fullName}}</td>
{{/view}}
{{/collection}}
Javascript:
App = Ember.Application.create();
App.Person = Ember.Object.extend({
fullName: function() {
return this.get('firstName') + ' ' + this.get('lastName');
}.property('firstName', 'lastName')
});
App.peopleController = Ember.ArrayController.create({
content: [App.Person.create({ firstName: "Yehuda", lastName: "Katz" }),
App.Person.create({ firstName: "Tom", lastName: "Dale" })]
});
App.PersonView = Ember.View.extend({
tagName: 'tr',
indexParent: null
});​

Answer 2

If you use a CollectionView the items/views of that collection can query it and see if they are the last item.
Fiddle: http://jsfiddle.net/qKXJt/138/
ArrayControllers are just proxies to their content, which is an Ember Array. This means you get all the goodies that come with Enumerable, Array, MutableArray, and so on.