{Unit to export a dataset to XML}
unit DS2XML;
interface
uses
 Classes, DB;
procedure DatasetToXML(Dataset: TDataSet; FileName: string);
implementation
uses
 SysUtils;
var
 SourceBuffer: PChar;
procedure WriteString(Stream: TFileStream; s: string);
begin
 StrPCopy(SourceBuffer, s);
 Stream.Write(SourceBuffer[0], StrLen(SourceBuffer));
end;
procedure WriteFileBegin(Stream: TFileStream; Dataset: TDataSet);
 function XMLFieldType(fld: TField): string;
 begin
  case fld.DataType of
  ftString: Result := '"string" WIDTH="' + IntToStr(fld.Size) + '"';
  ftSmallint: Result := '"i4"'; //??
  ftInteger: Result := '"i4"';
  ftWord: Result := '"i4"'; //??
  ftBoolean: Result := '"boolean"';
  ftAutoInc: Result := '"i4" SUBTYPE="Autoinc"';
  ftFloat: Result := '"r8"';
  ftCurrency: Result := '"r8" SUBTYPE="Money"';
  ftBCD: Result := '"r8"'; //??
  ftDate: Result := '"date"';
  ftTime: Result := '"time"'; //??
  ftDateTime: Result := '"datetime"';
  else
  end;
  if fld.Required then
  Result := Result + ' required="true"';
  if fld.ReadOnly then
  Result := Result + ' readonly="true"';
 end;
var
 i: Integer;
begin
 WriteString(Stream, '<?xml version="1.0" standalone="yes"?><!-- Generated by SMExport --> ' +
  '<DATAPACKET Version="2.0">');
 WriteString(Stream, '<METADATA><FIELDS>');
 {write th metadata}
 with Dataset do
  for i := 0 to FieldCount - 1 do
  begin
  WriteString(Stream, '<FIELD attrname="' +
  Fields[i].FieldName +
  '" fieldtype=' +
  XMLFieldType(Fields[i]) +
  '/>');
  end;
 WriteString(Stream, '</FIELDS>');
 WriteString(Stream, '<PARAMS DEFAULT_ORDER="1" PRIMARY_KEY="1" LCID="1033"/>');
 WriteString(Stream, '</METADATA><ROWDATA>');
end;
procedure WriteFileEnd(Stream: TFileStream);
begin
 WriteString(Stream, '</ROWDATA></DATAPACKET>');
end;
procedure WriteRowStart(Stream: TFileStream; IsAddedTitle: Boolean);
begin
 if not IsAddedTitle then
  WriteString(Stream, '<ROW');
end;
procedure WriteRowEnd(Stream: TFileStream; IsAddedTitle: Boolean);
begin
 if not IsAddedTitle then
  WriteString(Stream, '/>');
end;
procedure WriteData(Stream: TFileStream; fld: TField; AString: ShortString);
begin
 if Assigned(fld) and (AString <> '') then
  WriteString(Stream, ' ' + fld.FieldName + '="' + AString + '"');
end;
function GetFieldStr(Field: TField): string;
 function GetDig(i, j: Word): string;
 begin
  Result := IntToStr(i);
  while (Length(Result) < j) do
  Result := '0' + Result;
 end;
var
 Hour, Min, Sec, MSec: Word;
begin
 case Field.DataType of
  ftBoolean: Result := UpperCase(Field.AsString);
  ftDate: Result := FormatDateTime('yyyymmdd', Field.AsDateTime);
  ftTime: Result := FormatDateTime('hhnnss', Field.AsDateTime);
  ftDateTime:
  begin
  Result := FormatDateTime('yyyymmdd', Field.AsDateTime);
  DecodeTime(Field.AsDateTime, Hour, Min, Sec, MSec);
  if (Hour <> 0) or (Min <> 0) or (Sec <> 0) or (MSec <> 0) then
  Result := Result + 'T' + GetDig(Hour, 2) + ':' + GetDig(Min,
  2) + ':' + GetDig(Sec, 2) + GetDig(MSec, 3);
  end;
  else
  Result := Field.AsString;
 end;
end;
procedure DatasetToXML(Dataset: TDataSet; FileName: string);
var
 Stream: TFileStream;
 bkmark: TBookmark;
 i: Integer;
begin
 Stream := TFileStream.Create(FileName, fmCreate);
 SourceBuffer := StrAlloc(1024);
 WriteFileBegin(Stream, Dataset);
 with DataSet do
 begin
  DisableControls;
  bkmark := GetBookmark;
  First;
  {write a title row}
  WriteRowStart(Stream, True);
  for i := 0 to FieldCount - 1 do
  WriteData(Stream, nil, Fields[i].DisplayLabel);
  {write the end of row}
  WriteRowEnd(Stream, True);
  while (not EOF) do
  begin
  WriteRowStart(Stream, False);
  for i := 0 to FieldCount - 1 do
  WriteData(Stream, Fields[i], GetFieldStr(Fields[i]));
  {write the end of row}
  WriteRowEnd(Stream, False);
  ;
  end;
  GotoBookmark(bkmark);
  EnableControls;
 end;
 WriteFileEnd(Stream);
 Stream.Free;
 StrDispose(SourceBuffer);
end;
end.

//Beispiel, Example:

uses DS2XML;
procedure TForm1.Button1Click(Sender: TObject);
 begin DatasetToXML(Table1, 'test.xml');
 end;