Question

I have the following model:

    var User = Backbone.Model.extend({
            defaults: {
                status:     this.constructor.status.OFFLINE,
            },
        },
        {
            status:   {
                OFFLINE: 0,
                ONLINE:  1,
                BUSY:    2,
                AWAY:    3,
            },
        }
    );

I also tried:

status:     User.status.OFFLINE

but I keep getting this error:

TypeError: 'undefined' is not an object (evaluating 'this.constructor.status.OFFLINE')

or this:

TypeError: 'undefined' is not an object (evaluating 'User.status')

Any help? Thanks

Answer 1

You are trying to reference a static property that is not defined at the moment you create your User model.

Either define your defaults as a function

var User = Backbone.Model.extend({
    defaults: function() {
        return {status: User.status.OFFLINE}
    }
}, {
    status:   {
        OFFLINE: 0,
        ONLINE:  1,
        BUSY:    2,
        AWAY:    3
    }
});

http://jsfiddle.net/nikoshr/6XuC8/

or define first your static properties and then extend User.prototype to add your defaults:

var User = Backbone.Model.extend({}, {
    status:   {
        OFFLINE: 0,
        ONLINE:  1,
        BUSY:    2,
        AWAY:    3
    }
});

_.extend(User.prototype, {
    defaults: {
        status: User.status.OFFLINE
    }
});

var u = new User();
console.log(u.get('status'));

http://jsfiddle.net/nikoshr/6XuC8/2/