Override saveCompat for WordPress Media Uploader

Question

I am new to Backbone , so can't understand what I am doing wrong. What I need is to override saveCompat ( media-models.js line 310 , WP 3.9.1 ). I am trying to do it same way I have overridden some media views

wp.media.model.Attachment = wp.media.model.Attachment.extend({

    saveCompat: function( data, options ) {
        some code here...
    }
});

But it doesn't work for me. Native WordPress saveCompat is executed. At the same time the very same idea is perfectly working for wp.media.view.AttachmentCompat for example

wp.media.view.AttachmentCompat = wp.media.view.AttachmentCompat.extend({

    save: function( event ) {
        some code here...
    }
});

Thanks in advance!

Answer 1

I figured it out. The correct way to extend it is:

_.extend( wp.media.model.Attachment.prototype, {

    saveCompat: function( data, options ) {
        some code here...
    }
});

Answer 2

Using _.extend removes the ability to call the super class implementation of methods. The proper (or at least a working) way to do it is to use Backbone's extend method and then overwrite the prototype in wp.media.model.Attachment like this:

var MediaCreditAttachmentModel = wp.media.model.Attachment.extend( {
        saveCompat: function( data, options ) {
           ...
        }
} );

wp.media.model.Attachment.prototype = MediaCreditAttachmentModel.prototype;