Add functions for async operations

Author: na2axl

src/Util.js

@@ -1,7 +1,7 @@
 /**
  * JSONDB - JSON Database Manager
  *
- * Manage JSON files as databases with JSON Query Language (JQL)
+ * Manage JSON files as databases with JSONDB Query Language (JQL)
  *
  * This content is released under the GPL License (GPL-3.0)
  *
@@ -307,13 +307,14 @@ var Util = (function () {
  length = length || l;
 
  var ret = {};
- var i = 0;
+ var i = j = 0;
  for (var key in object) {
  if (object.hasOwnProperty(key)) {
- if (i > offset && i < length) {
+ if (i >= offset && j < length) {
  ret[key] = object[key];
+ ++j;
  }
- i++;
+ ++i;
  }
  }
  return ret;
@@ -327,7 +328,9 @@ var Util = (function () {
  */
  Util.prototype.extends = function (child, parent) {
  for (var key in parent) {
- if (parent.hasOwnProperty(key)) child[key] = parent[key];
+ if (parent.hasOwnProperty(key)) {
+ child[key] = parent[key];
+ }
  }
  function Ctor() {
  this.constructor = child;
@@ -480,8 +483,41 @@ var Util = (function () {
  return server + '/' + database;
  };
 
+ /**
+ * Add 0 to a number lower than 10
+ * @param {number|string} number
+ * @return {string}
+ */
+ Util.prototype.zeropad = function (number) {
+ number = parseInt(number);
+ if (number < 10 && number >= 0) {
+ number = '0' + number;
+ }
+ return number;
+ };
+
+ /**
+ * Asynchronous while
+ * @param {function} condition The while condition
+ * @param {function} bridge The function used for recursion
+ * @param {function} callback The callback function
+ */
+ Util.prototype.whilst = function(condition, bridge, callback) {
+ try {
+ if (condition() === false) {
+ return callback(null);
+ }
+ return bridge(function() {
+ this.whilst(condition, bridge, callback);
+ }.bind(this));
+ }
+ catch (e) {
+ return callback(e);
+ }
+ };
+
  return Util;
 })();
 
 // Exports the module
-module.exports = new Util();
+module.exports = new Util();