Overriding Backbone.sync to POST instead of PUT/DELETE/PATCH

backbone-sync-override.js

// The following could have been replaced by setting `Backbone.emulateHTTP = true;`

Backbone._sync = Backbone.sync;
Backbone.sync = function( method, model, options ) {
    var beforeSend = options.beforeSend;

    options = options || {};
  
    if ( method === "update" || method === "delete" || method === "patch" ) {
        options.beforeSend = function( xhr ) {
            xhr.setRequestHeader( "X-HTTP-Method-Override", method );
            if ( beforeSend ) { beforeSend.apply( this, arguments ); }    
            method = "create";                        
        };
    }
   
    return Backbone._sync( method, model, options );
};

var Contact = Backbone.Model.extend({ urlRoot: "/contacts" });

var john = new Contact({ id: 42, firstName: "John", lastName: "Smith" });

john.save(); // POST instead of PUT with X-HTTP-Method-Override of `create`