ArchiveReader and Streams

adam

Hi,

Just wondering if there is an example on how to use the archive reader with a stream, or if you can please advise what is wrong with the below code?

MS1 := TMemoryStream.Create;
lArchiveReader := TppArchiveReader.Create(nil);
lArchiveDevice := TppArchiveDevice.Create(nil);
lArchiveDevice.Publisher := lArchiveReader.Publisher;
lArchiveDevice.OutputStream := MS1;
if not Table.isempty then
begin
while not Table.eof do
begin
MS2 := TMemoryStream.create;
TableReportData.SaveToStream(MS2);
MS2.position := 0;
lArchiveDevice.StartPrintJob := Table.Bof;
lArchiveDevice.EndPrintJob := (Table.RecNo = Table.RecordCount);
lArchiveReader.ArchiveStream := MS2;
lArchiveReader.PrintToDevices;
MS2.free;
Table.next;
end;

lArchiveReader.AllowPrintToFile := true;
lArchiveReader.ShowPrintDialog := False;
lArchiveReader.DeviceType := dtPDF;

lArchiveReader.PDFSettings.Author := Appname;
lArchiveReader.PDFSettings.Title := 'Title';
lArchiveReader.PDFSettings.OpenPDFFile := false;
lArchiveReader.TextFileName := 'c:\temp\merged.pdf';
lArchiveReader.Print;

ms1.free;
lArchiveDevice.Free;
lArchiveReader.Free;

Thanks & Regards

Adam.

nicocizik

Hi Adam,

The issue is that your merged archive data is held in the MS1 stream, yet you never assign it to the ArchiveReader after the loop.

Your code above merges multiple archives to a single archive, then exports that to PDF. You could skip the first step and merge the multiple archives (from your DB) directly to PDF.

begin

  lArchiveReader := TppArchiveReader.Create(nil);
  lPDFDevice := TppPDFDevice.Create(nil);

  try

  lPDFDevice.FileName := 'c:\temp\merged.pdf';
  lPDFDevice.PDFSettings.Title := 'Title';
  lPDFDevice.OpenFile := False;

  lPDFDevice.Publisher := lArchiveReader.Publisher;

  if not(Table.isempty) then
    begin

      while not(Table.eof) do
        begin
          MS2 := TMemoryStream.create;
          try
            TableReportData.SaveToStream(MS2);
            MS2.position := 0;
            lPDFDevice.StartPrintJob := Table.Bof;
            lPDFDevice.EndPrintJob := (Table.RecNo = Table.RecordCount);
            lArchiveReader.ArchiveStream := MS2;
            lArchiveReader.PrintToDevices;
            Table.next;
          finally
            MS2.free;
          end;
        end;
    end;

  finally
    lPDFDevice.Free;
    lArchiveReader.Free;
  end;

end;

adam

Wonderful - thanks Nico!

And thanks for all your help this year too!

adam

Hi Nard,

Just a quick question. Instead of using

lPDFDevice.FileName := 'c:\temp\merged.pdf';

I was hoping to save the end result to MS1. (TMemoryStream). Just wondering if this is possible, or whether I have to offload it to a file, and then re-import it?

Thanks & Regards

Adam.

nicocizik

Hi Adam,

Rather than assigning the FileName of the PDFDevice, simply set its OutputStream property to the memory stream you would like to write to (MS1).

begin

  MS1 := TMemoryStream.Create;
  lArchiveReader := TppArchiveReader.Create(nil);
  lPDFDevice := TppPDFDevice.Create(nil);

  try

  lPDFDevice.OutputStream := MS1;

...

adam

Thanks Nico. Got it all working well now! Appreciate the help.

adam

For anyone else who may come across this in the future, I ran into some issues with this still not working, and had to add the line:

lDevice.reset

after each itteration of PrintToDevices.


The end result is the following functions/procedures which I leave here in case it may come in handy for anyone else looking to do anything similar in the future. (Or incase I forget and find my own question 10 years from now... it's happened before ;-)

function CombineReports(const ReportList: TList<TMemoryStream>): TMemoryStream;
var
  lArchiveReader: TppArchiveReader;
  lDevice: TppArchiveDevice;
  i: Integer;
begin
  Result := TMemoryStream.Create;
  lArchiveReader := TppArchiveReader.Create(nil);
  try
    lDevice := TppArchiveDevice.Create(nil);
    try
      lDevice.Publisher := lArchiveReader.Publisher;
      lDevice.OutputStream := Result;

      for i := 0 to ReportList.Count - 1 do
      begin
        lDevice.StartPrintJob := (i = 0);
        lDevice.EndPrintJob := (i = ReportList.Count - 1);
        lArchiveReader.ArchiveStream := ReportList[i];
        lArchiveReader.PrintToDevices;
        lDevice.reset;
      end;
    finally
      lDevice.Free;
    end;
  finally
    lArchiveReader.Free;
  end;
end;


procedure RenderRBArchivesToStream(ML: TList<TMemoryStream>; var MS: TMemoryStream; DeviceType: string = dtPDF);
var
  ms1: TMemoryStream;
  LDevice: TppArchiveDevice;
  LPDFDevice: TppPDFDevice;
  lArchiveReader: TppArchiveReader;
begin
  if ML = nil then
    exit;

  try
    MS1 := CombineReports(ML);


    if MS1 <> nil then
    begin
      if DeviceType = dtArchive then
        MS.LoadFromStream(MS1)
      else
      begin
        lArchiveReader := TppArchiveReader.Create(nil);
        lPDFDevice := TppPDFDevice.Create(nil);
        LPDFDevice.Publisher := lArchiveReader.Publisher;
        LPDFDevice.outputstream := MS;
        LPDFDevice.StartPrintJob := true;
        LPDFDevice.EndPrintJob := true;
        lArchiveReader.ArchiveStream := ms1;
        lArchiveReader.PrintToDevices;

        LPDFDevice.Free;
        lArchiveReader.Free;
      end;

      FreeAndNil(MS1);
    end;

  except
    try
      LDevice.Free;
      lArchiveReader.Free;
    finally

    end;
    raise;
  end;

end;


procedure PrintToStream(Report: TPPReport; var MS: TMemoryStream);
var
  LDevice: TppArchiveDevice;
begin
  ms := TMemoryStream.create;
  lDevice := TppArchiveDevice.Create(nil);
  if not assigned(MS) then
    ms := TMemoryStream.create
  else
    ms.clear;

  try
    lDevice.OutputStream := MS; // assign output stream
    lDevice.Publisher := Report.Publisher;
    Report.PrintToDevices;
    ldevice.free;
  except
    ldevice.free;
    raise;
  end;
  MS.Position := 0;
end;