Question

I have a Backbone model:

var User = Backbone.Model.extend({
  idAttribute: '_id',

  url: '/api/user',

  defaults:
    { username: ''
    },

  initialize: function () {
    console.log(this, this.isNew());
  }
});

Then I initialise the model and fetch the instance:

var user = new User();

user.fetch();

This works. If I inspect user, there is an id property. It exists on the server. However, for some reason user.isNew() is reporting true – even though it has an id property set (property as well as attribute). I need to update this model on the server but Backbone insists on sending POST requests, when I need PUT…

Answer 1

initialize runs before the fetch is completed. isNew value will change until the server answer arrives. Listen for the change event on the model or pass a callback to the fetch call.

var user = new User();

user.fetch({success : function(){
  console.log( user.isNew() );
}});