Filtering and rearranging model/content in Ember Controllers - json

Question

Let's say I have a JSON array of data, something like:
[ {"name":"parijat","age":28},
{"name":"paul","age":28},
{"name":"steven","age"27},
...
]
that is part of my model, and this model is setup like this:
App.UserRoute = Ember.Route.extend({
model:function(){
return App.User.FIXTURES ; // defined above
}
});
I want to get the unique ages from this JSON array and display them in my template, so I reference the computed properties article and read up a little on how to enumerate Ember Enumerables, to eventually get this:
App.UserController = Ember.ArrayController.extend({
ages:function(){
var data = this.get('content');
var ages = data.filter(function(item){
return item.age;
});
}.property('content');
});
Now the above piece of code for controller is not correct but the problem is that it doesn't even go into data.filter() method if I add a console.log statements inside. IMO, it should typically be console logging as many times as there exist a App.Users.FIXTURE. I tried using property('content.#each') which did not work either. Nor did changing this.get('content') to this.get('content.#each') or this.get('content.#each').toArray() {spat an error}.
Not sure what to do here or what I am completely missing.

Answer 1

Filter is used for reducing the number of items, not for mapping.
You can use data.mapBy('age') to get an array of your ages:
ages:function(){
return this.get('content').mapBy('age');
}.property('content.#each')
or in your handlebars function you can just use the each helper:
{{#each item in controller}}
{{item.age}}
{{/each}}