What's the best way to override Model.get(attr) in Backbone.js?

Question

I\'m using Backbone.js for the first time, and liking it so far. One thing I can\'t work out at the moment in dynamic attributes of models. For example, say I have a Person

Answer 1

The actual properties used by Model.get are stored in the attribute property. You could do something like this:

// function to cross-browser add a property to an object
function addProperty(object, label, getter, setter) {
    if (object.defineProperty){
      object.defineProperty(object, label, {getter: getter, setter: setter})
    }
    else {
        object.__defineGetter__(label, getter)
        object.__defineSetter__(label, setter)
    }
}

// inside the initializer of your model, add a property to the attribute object
var Person = Backbone.Model.extend({
    initialize: function(attr, options) {
        var t = this;
        ...
        addProperty(this.attributes, 'fullName',
            function() {return t.get('firstName') + ' ' + t.get('surname'),     
            function(val) {...}
        )
    }  
})

This will allow you to do person.get('fullName') as you requested.

Edit: To be clear, I agree with Bill's answer below. Shouldn't really be dinking around with the internal implementation of backbone.js. Especially since this is incomplete...what about escape() instead of get()? And the setter is more complex, as it does validation, change notification, etc...now I'm sorry I posted this :)