internal DynamicExpression(Report rpt, ReportLink p, string expr, Row row)
		{
			_Source=expr;
			_Expr = null;
            _rl = p;
            _Type = DoParse(rpt);
		}

		public string EvaluateString(Report rpt, Row row)
		{
			if (rpt == null || rpt.UserID == null)
				return Environment.UserName;
			else
				return rpt.UserID;
		}

		public object Evaluate(Report rpt, Row row)
		{
			bool bSave=true;
			IEnumerable re = this.GetDataScope(rpt, row, out bSave);
			if (re == null)
				return null;

			object v = GetValue(rpt);
			if (v == null)
			{
				object max_value=null;
				object current_value;

				foreach (Row r in re)
				{
					current_value = _Expr.Evaluate(rpt, r);
					if (current_value == null || (current_value is double && double.IsNaN((double)current_value)))
						continue;
					else if (max_value == null)
						max_value = current_value;
					else if (Filter.ApplyCompare(_tc, max_value, current_value) < 0)
						max_value = current_value;
				}
				v = max_value;
				if (bSave)
					SetValue(rpt, v);
			}
			return v;
		}

		public double EvaluateDouble(Report rpt, Row row)
		{
			bool bSave=true;
			IEnumerable re = this.GetDataScope(rpt, row, out bSave);
			if (re == null)
				return double.NaN;

			ODouble v = GetValueDouble(rpt);
			if (v != null)
				return v.d;

			double sum=0;
			int count=0;
			double temp;
			foreach (Row r in re)
			{
				temp = _Expr.EvaluateDouble(rpt, r);
				if (temp.CompareTo(double.NaN) != 0)
				{
					sum += temp;
					count++;
				}
			}
			double result;
			if (count > 0)
				result = (sum/count);
			else
				result = double.NaN;

			if (bSave)
				SetValue(rpt, result);

			return result;
		}

		public int EvaluateInt32(Report rpt, Row row)
		{
			bool bSave=true;
			IEnumerable re = this.GetDataScope(rpt, row, out bSave);
			if (re == null)
				return int.MinValue;

			Row startrow=null;
			foreach (Row r in re)
			{
				startrow = r;			// We just want the first row
				break;
			}

			int count;

			object currentValue = _Expr.Evaluate(rpt, row);
			int incr = currentValue == null? 0: 1;
			if (row == startrow)
			{
				// must be the start of a new group
				count = incr;
			}
			else
			{
				count = GetValue(rpt) + incr;
			}

			SetValue(rpt, count);
			return count;
		}

		// Evaluate is for interpretation  (and is relatively slow)
		public object Evaluate(Report rpt, Row row)
		{
			double d = EvaluateDouble(rpt, row);
			if (d.CompareTo(double.NaN) == 0)
				return null;
			return (object) d;
		}

		public double EvaluateDouble(Report rpt, Row row)
		{
			bool bSave=true;
			IEnumerable re = this.GetDataScope(rpt, row, out bSave);
			if (re == null)
				return 0;

			int v = GetValue(rpt);
			if (v < 0)
			{
				object temp;
				int count=0;
				foreach (Row r in re)
				{
					temp = _Expr.Evaluate(rpt, r);
					if (temp != null)
					{
						count++;
					}
				}
				v = count;

				if (bSave)
					SetValue(rpt, v);
			}
			return (double) v;
		}

		internal float GetX2(Report rpt)
		{
			float x2=GetOffsetCalc(rpt)+LeftCalc(rpt);
			if (Width != null)
				x2 += Width.Points;
			return x2;
		}		

		public object Evaluate(Report rpt, Row row)
		{
			object v = null;
			if (row == null)
				return null;
			bool bSave=true;
			RowEnumerable re = this.GetDataScope(rpt, row, out bSave);
			if (re == null)
				return null;

			Row crow=null;
			bool bNext=false;
			foreach (Row r in re)
			{
				if (bNext)
				{
					crow = r;
					break;
				}
				if (r == row)
					bNext = true;
			}
			if (crow != null)
				v = _Expr.Evaluate(rpt, crow);
			return v;
		}

		internal void CleanUp(Report rpt)		// closes any connections
		{
			foreach (DataSourceDefn ds in _Items.Values)
			{
				ds.CleanUp(rpt);
			}
		}

        public byte[] GetFileBytes(Report report)
        {
            var pages = report.BuildPages();
            int width = (int)report.PageWidthPoints;
            int height = (int)report.PageHeightPoints;
            string filename = string.Format("gen-{0}.pdf", Guid.NewGuid());
			
            try
            {
                using (Cairo.PdfSurface pdf = new Cairo.PdfSurface(filename, width, height))
                {
                    using (Cairo.Context g = new Cairo.Context(pdf))
                    {
						
                        var render = new  fyiReporting.RdlGtkViewer.RenderCairo(g);
                        render.RunPages(pages);
                    }
                }
                byte[] bytes = File.ReadAllBytes(filename);
                return bytes;
				
            }
            finally
            {
                if (File.Exists(filename))
                {
                    File.Delete(filename);
                }
            }
        }

        TextWriter tw; // where the output is going

        #endregion Fields

        #region Constructors

        public RenderXml(Report rep, IStreamGen sg)
        {
            r = rep;
            tw = sg.GetTextWriter();
            stkReportItem = new Stack();
            stkContainers = new Stack();
        }

		public string EvaluateString(Report rpt, Row row)
		{
			if (rpt == null || rpt.ClientLanguage == null)
				return CultureInfo.CurrentCulture.ThreeLetterISOLanguageName;
			else
				return rpt.ClientLanguage;
		}

        IStreamGen _sg; // stream generater

        #endregion Fields

        #region Constructors

        public RenderExcel(Report rep, IStreamGen sg)
        {
            r = rep;
            _sg = sg;					// We need this in future

            _Excel = new ExcelValet();
        }

		public double EvaluateDouble(Report rpt, Row row)
		{
			bool bSave=true;
			RowEnumerable re = this.GetDataScope(rpt, row, out bSave);
			if (re == null)
				return 0;

			int v = GetValue(rpt);
			if (v < 0)
			{
				object temp;
				int count = Math.Max(2, re.LastRow - re.FirstRow);
				Hashtable ht = new Hashtable(count);
				foreach (Row r in re)
				{
					temp = _Expr.Evaluate(rpt, r);
					if (temp != null)
					{
						object o = ht[temp];	// search for it
						if (o == null)			// if not found; add it to the hash table
						{
							ht.Add(temp, temp);
						}
					}
				}
				v = ht.Count;
				if (bSave)
					SetValue(rpt, v);
			}
			return (double) v;
		}

		internal void Save(Report rpt, System.IO.Stream stream, ImageFormat im)
		{
			if (_bm == null)
				Draw(rpt);
            _mf.Save(stream, im);
	//		_bm.Save(stream, im);
		}

		public object Evaluate(Report rpt, Row row)
		{
			bool bSave=true;
			IEnumerable re = this.GetDataScope(rpt, row, out bSave);
			if (re == null)
				return null;

			Row startrow=null;
			foreach (Row r in re)
			{
				startrow = r;			// We just want the first row
				break;
			}

			object v = GetValue(rpt);
			object current_value = _Expr.Evaluate(rpt, row);
			if (row == startrow)
			{}
			else
			{
				if (current_value == null)
					return v;
				else if (v == null)
				{}
				else if (Filter.ApplyCompare(_tc, v, current_value) > 0)
				{}
				else
					return v;
			}
			SetValue(rpt, current_value);
			return current_value;
		}

		public double EvaluateDouble(Report rpt, Row row)
		{
			bool bSave=true;
			IEnumerable re = this.GetDataScope(rpt, row, out bSave);
			if (re == null)
				return double.NaN;

			Row startrow=null;
			foreach (Row r in re)
			{
				startrow = r;			// We just want the first row
				break;
			}
			double currentValue = _Expr.EvaluateDouble(rpt, row);
			WorkClass wc = GetValue(rpt);
			if (row == startrow)
			{
				// must be the start of a new group
				wc.Value = currentValue;
				wc.Count = 1;
			}
			else
			{
				wc.Value = ((double) wc.Value + currentValue);
				wc.Count++;
			}

			return (double) wc.Value / wc.Count;
		}

		// 
		public virtual object Evaluate(Report rpt, Row row)
		{
			if (row == null)
				return null;
			Field f;
			string field = _ArgExpr.EvaluateString(rpt, row);
			if (field == null)
				return null;
			f = _Fields[field] as Field;
			if (f == null)
				return null;

			object o;
			if (f.Value != null)
				o = f.Value.Evaluate(rpt, row);
			else
				o = row.Data[f.ColumnNumber];

			if (o == DBNull.Value)
				return null;

			if (f.RunType == TypeCode.String && o is char)	// work around; mono odbc driver confuses string and char
				o = Convert.ChangeType(o, TypeCode.String);
			
			return o;
		}

		internal void SupplyValues(Report rpt, out string[] displayValues, out object[] dataValues)
		{
			displayValues = new string[_Items.Count];
			dataValues = new object[_Items.Count];
			int index=0;
			// go thru the parameters extracting the data values
			foreach (ParameterValue pv in _Items)
			{
				if (pv.Value == null)
					dataValues[index] = null;
				else
					dataValues[index] = pv.Value.Evaluate(rpt, null);
				if (pv.Label == null)
				{	// if label is null use the data value; if not provided use ""
					if (dataValues[index] == null)
						displayValues[index] = "";
					else
						displayValues[index] = dataValues[index].ToString();
				}
				else
				{
					displayValues[index] = pv.Label.EvaluateString(rpt, null);
					if (displayValues[index] == null)
						displayValues[index] = "";
				}
				index++;
			}
			return;
		}