add extend method

Author: z8

extend.js

@@ -0,0 +1,62 @@
+void function(global) {
+	if (!global.Box) {
+		global.Box = {};
+	}
+}(window)
+
+/**
+Merge the contents of two or more objects together into the first object.
+
+@methed Box.extend
+@param {Object} [, {Object}] [, {Object}] Objects you want to merge.
+@return {Object} Retrun merged object.
+@example
+   Box.extend({a: 'word'}, {a: 'string', b: {key: 'value'}})
+**/
+void function(Box){
+	var extend,
+		_extend,
+		_isObject;
+
+	_isObject = function(o){
+		return Object.prototype.toString.call(o) === '[object Object]';
+	}
+
+	_extend = function self(destination, source) {
+		var property;
+		for (var property in destination) {
+			if (destination.hasOwnProperty(property)) {
+
+				// when destination[property] is object and source[property] also is object
+				if (_isObject(destination[property]) && _isObject(source[property])) {
+					self(destination[property], source[property]);
+				};
+
+				if (source.hasOwnProperty(property)) {
+					continue;
+				} else {
+					source[property] = destination[property];
+				}
+			}
+		}
+	}
+
+	extend = function(){
+		var arr = arguments,
+			result = {},
+			i;
+
+		if (!arr.length) return {};
+
+		for (i = arr.length - 1; i >= 0; i--) {
+			if (_isObject(arr[i])) {
+				_extend(arr[i], result);
+			};
+		}
+
+		arr[0] = result;
+		return result;
+	}
+
+	Box.extend = extend;
+}(window.Box)