recordset.htm

网上商城的设计与实现

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

function _RS_getRecordSource()
{
	if (this._rsRDS != null)
		return this._rsRDS.recordset;

	return null;
}

//function _RS_setRecordSource(rsADO) OR
function _RS_setRecordSource(strConn,strSQL)
{
	if (typeof(strConn) == 'string')
	{	// given a connect and SQL string
		this._strConn = unescape(strConn);
		return this.setSQLText(strSQL);
	}

	if (typeof(strConn) == 'object')
	{	// given an ADO object
		this._strConn = '';
		this._strSQL = '';

		if (this._rsRDS != null)
			this._rsRDS.SourceRecordset = strConn;
		else
		{
			this._rsADO = strConn;
			this.open();
		}

		return true;
	}
	return false;
}

function _RS_open()
{
	this._objEventManager.fireEvent(RS_ONBEFOREOPEN);
	this._connect();
	if (this._rsADO != null)
		this._rsRDS.SourceRecordset = this._rsADO;
	this._objEventManager.fireEvent(RS_ONAFTEROPEN);
}

function _RS_isOpen()
{
	if (this._rsRDS != null)
	{
		if ((this._rsRDS.ReadyState == 2) || (this._rsRDS.ReadyState == 4))
			return true;
	}
	return false;
}

function _RS_close()
{
	this._rsRDS = null;
	this._count = -1;
}

function _RS_getConnectString()
{
	return this._strConn;
}

function _RS_getSQLText()
{
	if (this._rsRDS != null)
		return this._rsRDS.SQL;
	else
		return this._strSQL;
}

function _RS_setSQLText(strSQL)
{
	if (typeof(strSQL) == 'string')
	{
		this._strSQL = strSQL;
		if (this._rsRDS != null)
			this._rsRDS.SQL = strSQL;
		return true;
	}
	return false;
}

function _RS_requery()
{
	if (this.isOpen())
	{
		this._rsRDS.Refresh();
		this._count = -1;
	}
}

function _RS_setBookmark(bookmark)
{
	this._bookmark = bookmark;
	if (this.isOpen() && this._bookmark > 0)
	{
		if (this._rsRDS.recordset.Supports(8192))
		{	// supports bookmarks
			this._rsRDS.recordset.Bookmark = this._bookmark;
		}
		else
		{	// use AbsolutePosition
			this._rsRDS.recordset.AbsolutePosition =  this._bookmark * 1;
		}
		return true;
	}
	return false;
}

function _RS_getBookmark()
{
	if (this.isOpen())
	{
		if (this._rsRDS.recordset.Supports(8192))
		{	// supports bookmarks
			return this._rsRDS.recordset.Bookmark;
		}
		else
		{	// use AbsolutePosition
			return this._rsRDS.recordset.AbsolutePosition;
		}
	}
	return this._bookmark;
}

function _RS_isDHTMLAware()
{	return true;	}

function _RS_getDHTMLDataSourceID()
{
	if (this._rsRDS != null)
		return (this.name + '_RDS');
	return '';
}

function _RS__connect()
{
	var strServer = 'http://' + document.domain;
	var strRDS = '';
	strRDS = strRDS + '<' + 'OBJECT classid=clsid:BD96C556-65A3-11D0-983A-00C04FC29E33 height=1 style="LEFT: 0px; TOP: 0px" width=1';
	strRDS = strRDS + ' id=' + this.name + '_RDS>\n'; 
	strRDS = strRDS + '<PARAM NAME="Server" VALUE="' + strServer + '">\n';
	if (this._strConn != '')
		strRDS = strRDS + '<PARAM NAME="Connect" VALUE="' + encodeHTMLQuotes(this._strConn) + '">\n';
	if (this._strSQL != '')
		strRDS = strRDS + '<PARAM NAME="SQL" VALUE="' + encodeHTMLQuotes(this._strSQL) + '">\n';
	strRDS = strRDS + '</OBJECT>';
	this._spanTag.innerHTML = strRDS;
	this._rsRDS = document.all[this.name + '_RDS'];
	this.fields = CreateFields(this._rsRDS);
	this._rsRDS.onrowenter = _RS__onrowenter;
	this._rsRDS.onrowexit = _RS__onrowexit;
	this._rsRDS.ondatasetcomplete = _RS__ondatasetcomplete;
	this._rsRDS.ondatasetchanged = _RS__ondatasetchanged;
	this._bDSChanged = false;
	this._bDSComplete = false;
	this._count = -1;

	return true;
}

function _RS__fireEvent(funcToFire,bUseEvent)
{
	if ((typeof(bUseEvent) == 'boolean') && (bUseEvent))
	{
		var strRS = event.srcElement.id;
		strRS = strRS.substring(0,strRS.length-4);	// strip _RDS to get name
		var _objRS = eval(strRS);
		if (typeof(_objRS) == 'object')
		{
			if (funcToFire == RS_ONDATASETCOMPLETE)
			{
				_objRS._bDSComplete = true;
			}
			if (funcToFire == RS_ONDATASETCHANGED)
			{
				_objRS._syncBOFandEOF();
				_objRS.fields = CreateFields(_objRS._rsRDS);
				_objRS._bDSChanged = true;
			}
			if (funcToFire == RS_ONROWENTER)
			{
				if (_objRS._bFiringOnRowEnter)
					return;

				_objRS._bFiringOnRowEnter = true;
				_objRS._syncBOFandEOF();
				_objRS.fields = CreateFields(_objRS._rsRDS);
				_objRS._bFiringOnRowEnter = false;
			}
			if (_objRS._objEventManager != null)
				_objRS._objEventManager.fireEvent(funcToFire);
		}
	}
	else
	{	// fire recordset initFunc immediately
		if (typeof(funcToFire) == 'string')
			eval(funcToFire);
		else if (typeof(funcToFire) == 'function')
			funcToFire();
	}
}

function _RS__ondatasetcomplete()
{	_RS__fireEvent(RS_ONDATASETCOMPLETE,true);	}

function _RS__ondatasetchanged()
{	_RS__fireEvent(RS_ONDATASETCHANGED,true);	}

function _RS__onrowenter()
{	_RS__fireEvent(RS_ONROWENTER,true);	}

function _RS__onrowexit()
{	_RS__fireEvent(RS_ONROWEXIT,true);	}

function _RS__isEmpty()
{	return (!this.isOpen() || (this.BOF && this.EOF))	}

function _RS__onbeforefuncinit(objRecordset)
{
	objRecordset._objEventManager.adviseDefaultHandler(objRecordset.id,RS_ONBEFOREOPEN, true);
	objRecordset._objEventManager.adviseDefaultHandler(objRecordset.id,RS_ONROWENTER, true);
	objRecordset._objEventManager.adviseDefaultHandler(objRecordset.id,RS_ONROWEXIT, true);
	objRecordset._objEventManager.adviseDefaultHandler(objRecordset.id,RS_ONDATASETCHANGED, true);
	objRecordset._objEventManager.adviseDefaultHandler(objRecordset.id,RS_ONDATASETCOMPLETE, true);
	objRecordset._objEventManager.adviseDefaultHandler(objRecordset.id,RS_ONBEFOREUPDATE, true);
	objRecordset._objEventManager.adviseDefaultHandler(objRecordset.id,RS_ONAFTERUPDATE, true);
}

// ************************************************************************
// Fields Object
// ************************************************************************

function CreateFields(rsRDS)
{
	if (typeof(rsRDS) == 'object' && rsRDS != null)
		return new _Fields(rsRDS);
	return null;
}

function _Fields(rsTag)
{
	_Fields_Prototype();
	this.rsTag = rsTag;
}

function _Fields_Prototype()
{
	_Fields.prototype.getName = _FS_getName;
	_Fields.prototype.getValue = _FS_getValue;
	_Fields.prototype.setValue = _FS_setValue;
	_Fields.prototype.getCount = _FS_getCount;
	_Fields.prototype._isValid = _FS__isValid;
}

function _FS_getName(nIndex)
{
	if (typeof(nIndex) == 'number' && nIndex >= 0 && nIndex < this.getCount())
	{
		fsTmp =  this.rsTag.recordset.Fields;
		return fsTmp(nIndex).name;
	}
	return '';
}

function _FS_getValue(field)
{
	var r = '';
	if (this._isValid() && (typeof(field) == 'number' || typeof(field) == 'string'))
	{
		fsTmp =  this.rsTag.recordset.Fields;
		r = fsTmp(field).value;
		if (r == null)
			r = '';
	}
	return r;
}

function _FS_setValue(field,value)
{
	if ((typeof(field) == 'number' || typeof(field) == 'string') && typeof(value) != 'undefined')
	{	// validate field as updatable
		if (this._isValid)
		{
			fsTmp =  this.rsTag.recordset.Fields;
			var nAttributes = Number(fsTmp(field).Attributes);
			if ((nAttributes & 4) || (nAttributes & 8))
			{	// field may be updated, adFldUpdatable=4, adFldUnknownUpdatable=8
				if (value == '' && (nAttributes & 32))
				{	// field is nullable, adFldIsNullable=32
					value = null;
				}
				fsTmp(field).value = value;
				return true;
			}
		}
	}
	return false;
}

function _FS_getCount()
{
	fsTmp =  this.rsTag.recordset.Fields;
	if (typeof(fsTmp) == 'object')
	    	return fsTmp.count;
	return 0;
}

function _FS__isValid()
{	return !(this.rsTag.recordset.BOF || this.rsTag.recordset.EOF);	}