easy-loop/lib/easy-async.js

Easy sync loop processing for Node.js

'use strict';
var loop = require('./easy-for');

function async(list, concurrency, cb){
  var isArr = list instanceof Array;
  var results = isArr ? [] : {};
  loop(list, concurrency, function(i, value, next){
    if(typeof value !== 'function' && typeof value === 'object')
    {
      var size = 1;
      var isArr = value instanceof Array;
      if(isArr) size = value.length;
      else  size = Object.keys(value).length;
      async(value, size, function(err, results2){
        if(isArr) results.push(results2);
        else      results[i] = !results2 ? null : results2;
        next(err);
      });
    }
    else
    {
      value(function(err, val){
        if(err) next(err);
        else
        {
          if(isArr) results.push(val);
          else      results[i] = val === undefined ? null : val;
          next();
        }
      });
    }
  }, function(err){
    if(cb) cb(err, results);
  });
}

module.exports.series = function(list, concurrency, cb){
  var t = typeof concurrency;
  if(t === 'function')
  {
    cb = concurrency;
    concurrency = 1;
  }
  else if(t === 'number' && t <= 0 || t !== 'number' && arguments.length === 3)
  {
    concurrency = 1;
  }
  async(list, concurrency, cb);
};
module.exports.parallel = function(list, cb){
  var isArr = list instanceof Array;
  async(list, isArr ? list.length : Object.keys(list).length, cb);
};