Backbone.js + Rails: Add Auth Token to Sync

gistfile1.js

// Adapted from: https://gist.github.com/1251730
// I like this technique better: https://gist.github.com/3960219
$(function(){
  var paramName = $("meta[name='csrf-param']").attr('content');
  var paramValue = $("meta[name='csrf-token']").attr('content');

  Backbone.sync = _.wrap(Backbone.sync, function(originalSync, method, model, success, error){
    if (method == 'create' || method == 'update' || method == 'delete') {

      // grab the token from the meta tag rails embeds
      var auth_options = {};
      auth_options[paramName] = paramValue;

      // set it as a model attribute without triggering events
      model.set(auth_options, {silent: true});
    }

    // proxy the call to the old sync method
    return originalSync(method, model, success, error);
  })
})