redactor-plugins.js

    },

    urlcache: {},
    fetch: function( url, data, callback ) {
      var urlcache = this.translatable.urlcache;
      if ( !urlcache[ url ] ) {
        urlcache[ url ] = $.Deferred(function( defer ) {
          $.ajax( url, { data: data, dataType: 'json' } )
            .then( defer.resolve, defer.reject );
        }).promise();
      }
      return urlcache[ url ].done( callback );
    },
  };
};