eventmgr.htm

网上商城的设计与实现

// ************************************************************************<BR>
// Microsoft Script Library<BR>
// Visual InterDev 6.0 EventManager Object 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 CreateEventManager(strName)
{
	if (typeof(strName) == 'string')
	{
		if (eval('typeof(_EM_' + strName + ')') != 'object')
			eval('_EM_' + strName + ' = new _EventManager()');
		return eval('_EM_' + strName);
	}
	return new _EventManager();
}

function _EventManager()
{
	_EM_Prototype();
	this._events = new Array;
	this._nLastAdviseID = 0;
}

function _EM_Prototype()
{
	_EventManager.prototype.advise = _EM_advise;
	_EventManager.prototype.adviseDefaultHandler = _EM_adviseDefaultHandler;
	_EventManager.prototype.unadvise = _EM_unadvise;
	_EventManager.prototype.fireEvent = _EM_fireEvent;
	_EventManager.prototype.getEventCount = _EM_getEventCount;
	_EventManager.prototype.getEvent = _EM_getEvent;
}

function _EM_Advisor()
{
	this.funcToCall = 0;
	this.nAdviseID = 0;
}

function _EM_advise(strEvent,funcToCall)
{
	if ((typeof(strEvent) == 'string') && 
		(strEvent != '') && 
		(typeof(funcToCall) != 'undefined'))
	{
		if (typeof(this._events[strEvent]) == 'undefined')
			this._events[strEvent] = new Array;

		var adviseList = this._events[strEvent];
		var objAdvisor = new _EM_Advisor;
		objAdvisor.funcToCall = funcToCall;
		objAdvisor.nAdviseID = ++this._nLastAdviseID;
		adviseList[adviseList.length] = objAdvisor;
		return this._nLastAdviseID;
	}
	return -1;
}

function _EM_adviseDefaultHandler(strName,strEvent,bVirtualEvent)
{
	var nAdviseID = -1;
	var strDefaultHandler = strName + '_' + strEvent;
	// temporarily commandeer the onerror event to prevent
	// error message for a known script engine 3.1 issue
	// when using typeof on a non-javascript function
	var fnUserErrorHandler = window.onerror;
	window.onerror = _EM__suppressError;
	// the 4.0 jscript engine will return 'unknown' for VBScript functions
	// this mechanism is used to wire-up virtual events, but real HTML events
	// are automatically fired by IE4 so real events should not be wired up or
	// the eventhandler will be called twice
	if (eval('typeof(' + strDefaultHandler + ')') == 'function' ||
		((typeof(bVirtualEvent) != 'undefined') && bVirtualEvent && eval('typeof(' + strDefaultHandler + ')') == 'unknown'))
		nAdviseID = this.advise(strEvent,strDefaultHandler + '()');
	window.onerror = fnUserErrorHandler;
	return nAdviseID;
}

function _EM__suppressError(msg,url,line)
{	// used to suppress harmless error message in 3.1 scripting engines
	window.event.returnValue = true;
}

function _EM_unadvise(strEvent,nAdviseID)
{
	if ((typeof(strEvent) != 'undefined') && 
		(nAdviseID != 'undefined') && 
		(typeof(this._events[strEvent]) != 'undefined'))
	{
		var adviseList = this._events[strEvent];
		var nLen = adviseList.length
		for (var i=0; i < nLen; i++)
		{
			if (adviseList[i].nAdviseID == nAdviseID)
			{
				for (var j = Number(i); j < nLen - 1; j++)
					adviseList[j] = adviseList[j+1];
				adviseList.length -= 1;
				return true;
			}
		}
	}
	return false;
}

function _EM_fireEvent(strEvent)
{
	if (typeof(this._events[strEvent]) != 'undefined')
	{
		var bReturn = true;
		var adviseList = this._events[strEvent];
		for (var i=0; i < adviseList.length; i++)
			_EM__fireEvent(adviseList[i].funcToCall);
	}
}

function _EM_getEventCount()
{
		var nLength = 0;
		for (var event in this._events)
			nLength++;
		return nLength;
}

function _EM_getEvent(nIndex)
{
	var i = 0;
	for (var event in this._events)
	{
		if (nIndex == i)
			return event;
	}
	return '';
}

function _EM__fireEvent(funcToFire)
{
	if (document.readyState != 'complete')
	{
		if (typeof(_EM__EventManager) == 'undefined' || _EM__EventManager == null)
		{
			_EM__EventManager = new _EventManager();
			document.onreadystatechange = _EM__fireInit;
		}
		_EM__EventManager.advise('oninit',funcToFire);
		return;
	}

	if (typeof(funcToFire) == 'string')
		eval(funcToFire);
	else if (typeof(funcToFire) == 'function')
		funcToFire();
}

function _EM__fireInit()
{
	if (document.readyState == 'complete')
	{
		_EM__EventManager.fireEvent('oninit');
		_EM__EventManager = null;	
	}
}

function encodeHTMLQuotes(strIn)
{
	var strOut;
	while (strOut != strIn)
	{
		strOut = strIn;
		strIn = strIn.replace('"', '&quot;');
	}
	
	return strOut;
}