when to use defaults vs the initialize constructor on a model

Question

So, I'm trying to learn how to use Backbone and I keep switching back and forth between using the defaults object and the initialize method. If I use the method, it's with "this.set()" to set attributes, etc. Otherwise those attributes are set in the default object.

I've looked around on google and I can't seem to find a recommended way or "common" pattern of when to use defaults or when to use initialize. I can make my code work both ways and both yield an object with the desired attributes, but it bugs me because i'm unsure if i'm using it incorrectly.

Answer 1

You would use the defaults object for all "static" data as you can only define them once for a model class. You will need the initialize method if you have to add dynamic per instance properties. For example:

initialize: function() {
  this.set({displayName: this.get('firstname') + this.get('lastname')});
}