miscutils.htm

网上商城的设计与实现

// ************************************************************************<BR>
// Microsoft Script Library<BR>
// Visual InterDev 6.0 Miscellaneous utility functions for DHTML<BR>
// Copyright 1998 Microsoft Corporation. All Rights Reserved.<BR>
// <B>Do not modify in design view. Switch to source view.</B><BR>
// ************************************************************************<BR>
// <SCRIPT>
//*****************************************************************
// function closure(obj,method)
//
//	Creates a closure object for encapsulating a function of an 
//	object instance.
//*****************************************************************
function closure(obj,method)
{
	return function() 
	{ 
		var params = ""; var i;

		for (i = 0; i < (arguments.length - 1); i++) 
		{	params += arguments[i] + ","	}

		if (i < arguments.length) 
		{	params += arguments[i];			}

		with (obj) 
			return eval(method + "(" + params + ")"); 
	};
}

//*****************************************************************
// function TypeOf(x)
//
//	Returns a string indicating the type of given variable x.
//	This is a specialized implementation of the native typeof
//	function which differentiates date and array objects.
//
//	Returns "undefined","function","string","boolean",
//			"number", "object", "array", or "date"
//*****************************************************************
function TypeOf(x)
{
	var t = typeof(x);
	if (t == "object" && x != null)
	{
		if (typeof(x.constructor) != "undefined")
		{ 
			var ctor = new String(x.constructor);
			var chStart = ctor.indexOf("function");
			var chEnd = ctor.indexOf("(");
			if (chStart != -1 && chEnd != -1)
			{
				ctor = ctor.substring(chStart+9,chEnd);
				if (ctor == "Array" || ctor == "Date" || ctor == "String" || ctor == "Number" || ctor == "Boolean")
					t = ctor.toLowerCase();
			}
		}
	}
	return t;
}

//*****************************************************************
// function QuickDictionary()
//
//	A quick and dirty implementation of a dictionary.
//*****************************************************************
function QuickDictionary()
{
	this.dict = new Object;
	this.items = new Array;
	this.count = 0;
	this.Add = new Function("key","item","this.dict[key] = this.count; this.items[this.count] = item; this.count++;");
	this.Exists = new Function("key","return (typeof(this.dict[key]) != \"undefined\");");
	this.Item = new Function("key","return this.items[this.dict[key]];");
	this.RemoveAll = new Function("","this.dict = new Object; this.items.length = 0; this.count = 0;");
}