A helper for working with Excel files in classic ASP using JScript

excel.asp

<%

var excel = (function () {

	var connection = null;
	
	function open(file) {
		connection = Server.createObject('ADODB.Connection'); 
		connection.CommandTimeout = 60;
		connection.CursorLocation = 3;
		connection.Open('Provider=Microsoft.ACE.OLEDB.12.0;Data Source='+file+';Extended Properties="Excel 12.0 Xml;HDR=YES;IMEX=1";');
		return this;
	};
	
	function query(sql, params, callback) {
		var sql = (params == null ? sql : replaceSQLParams(sql, params));
		var rsa = Server.CreateObject("ADODB.Recordset");
		rsa.open(sql, connection, 3, 3);
		if (typeof callback == 'function') {
			callback(resultSet(rsa));
		} else {
			return resultSet(rsa);
		}
		return this;
	};
	
	function close() {
		connection.close();
	};
	
	function each(sql, params, callback) {
		query(sql, params, function(data) {
			data.each(callback);
		});
	};

	function replaceSQLParams(s, p) {
		var r = s;
		for (var k in p) {
			if (typeof p[k] == 'string') {
				r = r.replace(new RegExp('@' + k, 'g'), '\'' + p[k].replace(/\'/g, '\'\'') + '\'');
			} else {
				r = r.replace(new RegExp('@' + k, 'g'), p[k]);
			}
		}
		return r;
	};

	
	// below a small interface with the native ado result set objects 
	
	function resultSet(nativeResultSet) {
		
		var fieldsCache = null;
		
		function each(f, dontClose) {
			for (var i = 0; !eof(); i++) 
				f(get(), i);
			if (!dontClose) rs_close();
		};
		
		function asArray() {
			var d = [];
			while (!eof())
				d.push(get());
			rs_close();
			return d;
		};

		function get(f) {
			if (eof()) return null;
			if (f) {
				var t = nativeResultSet.fields(f).value;
				if (typeof t == 'date') t = new Date(''+t).toISOString();
				return t;
			} else {
				var r = getObject();
				next();
				return r;
			}
		};

		function getObject() {
			var o = {};
			var fld = fields();
			for (var i = 0; i < fld.length; i++)
				o[fld[i]] = get(fld[i]);
			return o;
		};

		function next() {
			nativeResultSet.moveNext();
		};
		
		function eof() {
			return nativeResultSet.eof;
		};
		
		function numFields() {
			return nativeResultSet.fields.count;
		};

		function rowCount() {
			return nativeResultSet.recordCount;
		};

		function fields() {
			if (fieldsCache == null) {
				fieldsCache = [];
				var j = numFields();
				for (var i = 0; i < j; i++)
					fieldsCache.push(nativeResultSet.fields(i).name);
			}
			return fieldsCache;
		};
		
		function rs_close() {
			nativeResultSet.close();
		};
		
		return {
			eof: eof,
			each: each,
			get: get,
			next: next,
			fields: fields,
			numFields: numFields,
			rowCount: rowCount,
			close: rs_close,
			asArray: asArray
		};
	};
	
	return {
		open: open,
		query: query,
		close: close,
		each: each
	};
	
})();

%>