rsnavbar.htm

网上商城的设计与实现

// ************************************************************************<BR>
// Microsoft Script Library<BR>
// Visual InterDev 6.0 RecordsetNavbar 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 CreateRecordsetNavbar(strName,funcInit,objParent)
{
	if (typeof(strName) == 'string' && strName != '')
	{
		if (typeof(RSNB_ONFIRSTCLICK) == 'undefined')
		{	// define RSNB constants
			RSNB_ONFIRSTCLICK = 'onfirstclick';
			RSNB_ONPREVIOUSCLICK = 'onpreviousclick';
			RSNB_ONNEXTCLICK = 'onnextclick';
			RSNB_ONLASTCLICK = 'onlastclick';

			RSNB_BUTTONFIRST = 0;
			RSNB_BUTTONPREV = 1;
			RSNB_BUTTONNEXT = 2;
			RSNB_BUTTONLAST = 3;

			RSNB_ALIGN_VERTICAL = 0;
			RSNB_ALIGN_HORIZONTAL = 1;

			RSNB_MASK_FIRSTIMAGE = 1;
			RSNB_MASK_FIRSTCAPTION = 2;
			RSNB_MASK_PREVIMAGE = 4;
			RSNB_MASK_PREVCAPTION = 8;
			RSNB_MASK_NEXTIMAGE = 16;
			RSNB_MASK_NEXTCAPTION = 32;
			RSNB_MASK_LASTIMAGE = 64;
			RSNB_MASK_LASTCAPTION = 128;

			_RSNB_BUTTONCOUNT = 4;
			_RSNB_BUTTONNAMES = new Array('First','Previous','Next','Last');
		}
			
		if ((objParent != null) && (typeof(objParent) == 'object'))
		{
		    var strHTML = '<' + 'span name="' + strName + '" id="' + strName + '"></span>';
		    objParent.insertAdjacentHTML('BeforeEnd',strHTML);   
		}
		else
			document.write('<' + 'span name="' + strName + '" id="' + strName + '"></span>');
		
		objSpan = eval(strName);
		if ((objSpan == null) || (typeof(objSpan) != 'object'))
			return null;

		//public members
		objSpan.pageSize = 1;
		objSpan.updateOnMove = true;
		objSpan.isVisible = _RSNB_isVisible;
		objSpan.show = _RSNB_show;
		objSpan.hide = _RSNB_hide;
		objSpan.getAlignment = _RSNB_getAlignment;
		objSpan.setAlignment = _RSNB_setAlignment;
		objSpan.setButtonStyles = _RSNB_setButtonStyles; 
		objSpan.getButtonStyles = _RSNB_getButtonStyles; 
		objSpan.cancelOperation = _RSNB_cancelOperation;
		objSpan.isOperationCancelled = _RSNB_isOperationCancelled;
		objSpan.getButton = _RSNB_getButton;
		objSpan.getDataSource = _RSNB_getDataSource;
		objSpan.setDataSource = _RSNB_setDataSource;
		objSpan.display = _RSNB_display;
		objSpan.advise = _RSNB_advise;
		objSpan.unadvise = _RSNB_unadvise;
		
		//private members
		objSpan._onfirstclick = _RSNB__onfirstclick;
		objSpan._onpreviousclick = _RSNB__onpreviousclick;
		objSpan._onnextclick = _RSNB__onnextclick;
		objSpan._onlastclick = _RSNB__onlastclick;

		objSpan._nAlignment = RSNB_ALIGN_HORIZONTAL;
		objSpan._objDataSource = null;
		objSpan._fireEvent = _RSNB__fireEvent;
		objSpan._bCancelOperation = false;
		objSpan._nButtonMask = 0;
		objSpan._bCreated = false;

		// advise for default eventhandlers
		objSpan._objEventManager = CreateEventManager();
		objSpan._fireEvent('_RSNB__onbeforefuncinit(' + objSpan.id + ')');
		objSpan._fireEvent(funcInit);
			
		return objSpan;
	}
	return null;
}

function _RSNB__GenerateRecordsetNavbar(objSpan,nButtonMask)
{
	var strSepContent = '<br>';
	var strName = objSpan.name;
	var nAlignment = objSpan._nAlignment;
	this._nButtonMask = nButtonMask;	
	
	if (nAlignment == RSNB_ALIGN_HORIZONTAL)	
		strSepContent = ' ';
		
	var strSpanContent = ' ';
	var buttonType;
	var objButton = null;
		
	if ((nButtonMask & (RSNB_MASK_FIRSTIMAGE | RSNB_MASK_FIRSTCAPTION)) != 0)
	{
		buttonType = ((nButtonMask & RSNB_MASK_FIRSTIMAGE) != 0) ? 1 : 0;
		objButton = CreateButton(strName + '_Button0',null,objSpan);
		objButton.advise(BTN_ONCLICK,strName + '._onfirstclick()');
		objButton.setStyle(buttonType);
	        strSpanContent = strSepContent;
	}

	var strSeparatorSpan = '<span id="' + strName + '_Span0">' + strSpanContent + '</span>';
	objSpan.insertAdjacentHTML('BeforeEnd',strSeparatorSpan);
	strSpanContent = '';

	if ((nButtonMask & (RSNB_MASK_PREVIMAGE | RSNB_MASK_PREVCAPTION)) != 0)
	{
		buttonType = ((nButtonMask & RSNB_MASK_PREVIMAGE) != 0) ? 1 : 0;
		objButton = CreateButton(strName + '_Button1',null,objSpan);
		objButton.advise(BTN_ONCLICK,strName + '._onpreviousclick()');
		objButton.setStyle(buttonType);
	        strSpanContent = strSepContent;
	}

	strSeparatorSpan = '<span id="' + strName + '_Span1">' + strSpanContent + '</span>';
	objSpan.insertAdjacentHTML('BeforeEnd',strSeparatorSpan);
	strSpanContent = '';

	if ((nButtonMask & (RSNB_MASK_NEXTIMAGE | RSNB_MASK_NEXTCAPTION)) != 0)
	{
		buttonType = ((nButtonMask & RSNB_MASK_NEXTIMAGE) != 0) ? 1 : 0;
		objButton = CreateButton(strName + '_Button2',null,objSpan);
		objButton.advise(BTN_ONCLICK,strName + '._onnextclick()');
		objButton.setStyle(buttonType);
	        strSpanContent = strSepContent;
	}

	strSeparatorSpan = '<span id="' + strName + '_Span2">' + strSpanContent + '</span>';
	objSpan.insertAdjacentHTML('BeforeEnd',strSeparatorSpan);
	strSpanContent = '';
 
	if ((nButtonMask & (RSNB_MASK_LASTIMAGE | RSNB_MASK_LASTCAPTION)) != 0)
	{
		buttonType = ((nButtonMask & RSNB_MASK_LASTIMAGE) != 0) ? 1 : 0;
		objButton = CreateButton(strName + '_Button3',null,objSpan);
		objButton.advise(BTN_ONCLICK,strName + '._onlastclick()');
		objButton.setStyle(buttonType);
	}
	objSpan._bCreated = true;			
}


function _RSNB_isVisible()
{    return (this.style.visibility != 'hidden');	}

function _RSNB_show()
{    this.style.visibility = 'visible';	}

function _RSNB_hide()
{    this.style.visibility = 'hidden';	}

function _RSNB_getAlignment()
{    return this._nAlignment;	}

function _RSNB_setAlignment(nAlignment)
{
	if(!isNaN(parseInt(nAlignment)))
	{
		this._nAlignment = nAlignment;	
		if (this._bCreated)
		{
			var strToInsert = '<br>';
			if (nAlignment == RSNB_ALIGN_HORIZONTAL)
				strToInsert = '';
				
			for (var nIndex = 0; nIndex < 3; ++ nIndex)
			{
				var objSpan = document.all(this.id + '_Span' + nIndex)
				if ((objSpan != null) && (objSpan.innerHTML != strToInsert))
					objSpan.innerHTML = strToInsert;
			}
		}
		return true;
	}
	return false;
}

function _RSNB_setButtonStyles(nButtonMask)
{	_RSNB__GenerateRecordsetNavbar(this, nButtonMask);	}

function _RSNB_getButtonStyles()
{	return this._nButtonMask;	}
	
function _RSNB_cancelOperation()
{    this._bCancelOperation = true;		}

function _RSNB_isOperationCancelled()
{    return this._bCancelOperation;		}

function _RSNB_getButton(nIndex)
{
    if ((nIndex >= RSNB_BUTTONFIRST) && (nIndex <= RSNB_BUTTONLAST))
		return document.all(this.id + '_Button' + nIndex);
	return null;
}

function _RSNB_getDataSource()
{    return this._objDataSource;	}

function _RSNB_setDataSource(objRecordset)
{    this._objDataSource = objRecordset;	}

function _RSNB_advise(strEvent,funcToCall)
{    return this._objEventManager.advise(strEvent,funcToCall);	}

function _RSNB_unadvise(strEvent, nAdviseID)
{    return this._objEventManager.unadvise(strEvent, nAdviseID);	}

function _RSNB_display()
{	}

function _RSNB__onfirstclick()
{
	this._objEventManager.fireEvent(RSNB_ONFIRSTCLICK);
	if (this._objDataSource != null && !this._bCancelOperation)
	{
		if (this.updateOnMove)
			this._objDataSource.updateRecord();
		this._objDataSource.moveFirst();
	}
	else
		this._bCancelOperation = false;
}

function _RSNB__onpreviousclick()
{
	if (this._objDataSource == null)
	{
		this._objEventManager.fireEvent(RSNB_ONPREVIOUSCLICK);
		this._bCancelOperation = false;
	}
	else if (!this._objDataSource.BOF)
	{
		this._objEventManager.fireEvent(RSNB_ONPREVIOUSCLICK);
		if (!this._bCancelOperation)
		{
			if (this.updateOnMove)
				this._objDataSource.updateRecord();
			if (this.pageSize > 1)
			{	// move to first record of previous page
				var curPos = this._objDataSource.absolutePosition;
				var nCount = this._objDataSource.getCount();
				if (this._objDataSource.EOF)	curPos = nCount;
				if (curPos > 0 && nCount > 0)
				{
					var curPage = (curPos - (curPos % this.pageSize)) / this.pageSize;
					if (curPage > 1)
					{
						this._objDataSource.moveAbsolute(((curPage-1) * this.pageSize) + 1);
					}
					else
						this._objDataSource.moveFirst();
					return;
				}
			}

			// otherwise, move to previous record
			this._objDataSource.movePrevious();

			if (this._objDataSource.BOF)
				this._objDataSource.moveFirst();
		}
		else
			this._bCancelOperation = false;
	}
}

function _RSNB__onnextclick()
{
	if (this._objDataSource == null)
	{
		this._objEventManager.fireEvent(RSNB_ONNEXTCLICK);
		this._bCancelOperation = false;
	}
	else if (!this._objDataSource.EOF)
	{
		this._objEventManager.fireEvent(RSNB_ONNEXTCLICK);
		if (!this._bCancelOperation)
		{
			if (this.updateOnMove)
				this._objDataSource.updateRecord();
				
			if (this.pageSize > 1)
			{	// move to first record of next page
				var curPos = this._objDataSource.absolutePosition;
				var nCount = this._objDataSource.getCount();
				if (this._objDataSource.BOF)	curPos = 1;
				if (curPos > 0 && nCount > 0)
				{
					var curPage = (curPos - ((curPos - 1) % this.pageSize)) / this.pageSize;
					var newPos = curPage * this.pageSize;
					if (newPos + this.pageSize <= nCount)
						newPos += this.pageSize;
					this._objDataSource.moveAbsolute(newPos);
					return;
				}
			}

			// otherwise, move to next record
			this._objDataSource.moveNext();
				
			if (this._objDataSource.EOF)
				this._objDataSource.moveLast();
		}
		else
			this._bCancelOperation = false;
	}
}

function _RSNB__onlastclick()
{
	this._objEventManager.fireEvent(RSNB_ONLASTCLICK);
	if (this._objDataSource != null && !this._bCancelOperation)
	{
		if (this.updateOnMove)
			this._objDataSource.updateRecord();
		this._objDataSource.moveLast();
	}
	else
		this._bCancelOperation = false;
}

function _RSNB__fireEvent(funcToFire)
{
    if (typeof(funcToFire) == 'undefined')
		this._objEventManager.fireEvent('on' + window.event.type);
    else
        _EM__fireEvent(funcToFire);
}

function _RSNB__onbeforefuncinit(objSpan)
{
	objSpan._objEventManager.adviseDefaultHandler(objSpan.id, RSNB_ONFIRSTCLICK, true);
	objSpan._objEventManager.adviseDefaultHandler(objSpan.id, RSNB_ONPREVIOUSCLICK, true);
	objSpan._objEventManager.adviseDefaultHandler(objSpan.id, RSNB_ONNEXTCLICK, true);
	objSpan._objEventManager.adviseDefaultHandler(objSpan.id, RSNB_ONLASTCLICK, true);
}