How do I convert a filtered collection to JSON with Backbone.js?

Question

So I have a collection in Backbone for a list of events. This collection has a method on it which filters the list based on a list of categories passed to it.

var Events = Backbone.Collection.extend({
    model: Event,
    url: settings.events_url,
    filtered: function(checked) {
        return this.filter(function(e) {
            if ($.inArray(e.get('category').name, checked) >= 0) {
                return true;
            } else {
                return false;
            }
        });
    }
});

What I need to be able to do is convert this filtered collection to JSON, the same way you would do the collection as a whole.

var events = new Events();
events.toJSON();

However, because the filtered collection is no longer an actual collection, but rather a list of models, I don't have the .toJSON() method available to me. Is there a way to convert my filtered collection to a real collection? Or is there an easier way to convert it to JSON?

Thanks!

Answer 1

The constructor for a collection can take a list of models as an argument so:

var events = new Events();
var filteredEvents = new Events(events.filtered(true));
console.log(filteredEvents.toJSON());