Backbone.js collection with multiple sorts

Question

I have a todo list with name and date. I'd like to be able to sort the list using either the title or to the date. How would I do this? Comparator allows only one type of sorting.

Thanks.

Answer 1

It is possible to implement more logic into the comparator so that you can abstract away some of the sorting logic:

var Collection = Backbone.Collection.extend({

    model: myModel,
    order: 'name'

    comparator: function(model) {
        if (this.order === 'name') {
            return model.get('name');
        } else {
            return model.get('date'); //or modify date into a numeric value
        }
    }
});

Then to change how you want it sorted:

myCollection.order = 'date';
myCollection.sort();

This will call the comparator function and sort it this way.

You can listen for the resorting in a view:

this.listenTo(myCollection,'sort',this.render);

This has the added advantage that every time a model is added, it calls the comparator and sorts it using whatever your current setting is, because the sorting method is stored in the collection.

Answer 2

You may need to look at the answer here, here is the solution provided in that post:

comparator: function(item) {
    return [item.get("level"), item.get("title")]
}