Backbone JS enables you to create a JS application to connect with your existing API over a RESTful JSON interface.

Backbone defines some REST states to operate over models for instance:

• Model Fetch: GET
• Model New: POST
• Model Update: PUT

But is possible our API doesn’t implement all REST States, for instance, Drupal 8 (version in development) don’t implement the method PUT to save Drupal Entities yet.

In exchange, the REST State PATCH is used by Drupal to save models.

So if I try to create a regular Model, as you can see in the following snippet.

Node = Backbone.Model.extend({
        initialize: function(){
            alert("Welcome to this world");
        }
    });

var node = new Node({ id: 1, title: 'Node Sample in Backbone'});

node.save(userDetails, {
    success: function (user) {
        alert(user.toJSON());
    }
})

The code above will execute an Ajax call using PUT method.

If you are a Drupal Developer, you will notice the model doesn’t match the Drupal Entity structure with language and deltas, but I want to show a simple logic about Backbone save.

Now let me show you how we can overwrite the save function to change the REST method.

Node = Backbone.Model.extend({
        initialize: function(){
            alert("Welcome to this world");
        },
        save: function(attrs, options) {
          options.patch = true;
          // Proxy the call to the original save function
          Backbone.Model.prototype.save.call(this, attrs, options);
        }
    });

var node = new Node({ id: 1, title: 'Node Sample in Backbone'});

node.save(userDetails, {
    success: function (user) {
        alert(user.toJSON());
    }
})

Now our model will execute an Ajax request using PATCH method.

I used this technique to enable the library Backbone.Drupal send models to Drupal 8 using REST method PATCH.

I hope you found this blog entry useful.