Question

I’d like to set a model’s ID to the correct value after a fetch in all instances of a backbone collection, but this doesn’t seem to work:

var NoteCollection = Backbone.Collection.extend(
{
    model: Note,
    initialize: function () {
        this.bind("add", function (note) {
            if (!note.id && note.has('noteid'))
                note.id = note.get('noteid');
        });
    } 
});

The function never gets called (I’m testing by creating a new NoteCollection and calling fetch on it), what am I doing wrong?

Note: I know I could bind the method on a specific instance of NoteCollection, and that works, but I want to bind it on all instances.

Answer 1

It’s probably because note.id is returning true.

The good news is Backbone already has a convention to set the model’s id property to a specific attribute on the model. This is done by setting the idAttribute (See this line in Backbone’s source)

var Note = Backbone.Model.extend({
  idAttribute: 'noteid'
});

With this code, Backbone will take care of setting note.id = note.get('noteid')