paralell.js

/***
 * @function make the parallel request filters and finish with the last filter.
 *
 * @example
 *
 * misc.parallel(
 *    func1, func2, func3, func4
 * );
 *
 * func1 ---+
 *          |
 * func2 ---+---> func4
 *          |
 * func3 ---+
 *
 * all the filter functions takes 3 arguments (request, response, next)
 * as usual as Express way.
 */
exports.parallel = function(){
   var list = arguments;
   return function(req, res, next){
      var current = 0;
      var len = list.length;
      var last = list[len-1];
      function pass(i){
         return function(){
            current += 1;
            if( current == len - 1 ){
               last(req, res, next);
            }
         };
      }
      for(var i=0; i<len-1;i++){
         var fun = list[i];
         fun(req, res, pass(i));
      }
   };
}