dojo.provide("dojox.lang.oo.general");

dojo.require("dojox.lang.oo.Decorator");

(function(){
	var oo = dojox.lang.oo, md = oo.makeDecorator, oog = oo.general,
		isF = dojo.isFunction;

	// generally useful decorators

	oog.augment = md(function(name, newValue, oldValue){
		// summary:
		//		add property, if it was not defined before
		return typeof oldValue == "undefined" ? newValue : oldValue;
	});

	oog.override = md(function(name, newValue, oldValue){
		// summary:
		//		override property only if it was already present
		return typeof oldValue != "undefined" ? newValue : oldValue;
	});

	oog.shuffle = md(function(name, newValue, oldValue){
		// summary:
		//		replaces arguments for an old method
		return isF(oldValue) ?
			function(){
				return oldValue.apply(this, newValue.apply(this, arguments));
			} : oldValue;
	});

	oog.wrap = md(function(name, newValue, oldValue){
		// summary:
		//		wraps the old values with a supplied function
		return function(){ return newValue.call(this, oldValue, arguments); };
	});

	oog.tap = md(function(name, newValue, oldValue){
		// summary:
		//		always returns "this" ignoring the actual return
		return function(){ newValue.apply(this, arguments); return this; };
	});

	oog.before = md(function(name, newValue, oldValue){
		// summary:
		//		creates a chain of calls where the new method is called
		//		before the old method
		return isF(oldValue) ?
			function(){
				newValue.apply(this, arguments);
				return oldValue.apply(this, arguments);
			} : newValue;
	});

	oog.after = md(function(name, newValue, oldValue){
		// summary:
		//		creates a chain of calls where the new method is called
		//		after the old method
		return isF(oldValue) ?
			function(){
				oldValue.apply(this, arguments);
				return newValue.apply(this, arguments);
			} : newValue;
	});
})();
