Lazarus Pascal

Explaining the Rest ClearResponseBodyStream Method

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The ClearResponseBodyStream method would be needed if your applicaiton called SetResponseBodyStream to send the response to a stream for one request, but then wants to subsequently do something else. The application must call ClearResponseBodyStream to no longer send responses to the stream. Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.BinData,
  Chilkat.Rest,
  Chilkat.Stream;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  rest: TRest;
  bTls: Boolean;
  port: Integer;
  bAutoReconnect: Boolean;
  fileStream: TStream;
  expectedStatus: Integer;
  responseStr: string;
  bd: TBinData;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  rest := TRest.Create;

  //  Connect to the web server
  bTls := True;
  port := 443;
  bAutoReconnect := True;
  success := rest.Connect('www.chilkatsoft.com',port,bTls,bAutoReconnect);
  if (success <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  Setup a file stream for the download
  fileStream := TStream.Create;
  fileStream.SinkFile := 'qa_output/starfish.jpg';

  //  Indicate that the call to FullRequestNoBody should send the response body
  //  to fileStream if the response status code is 200.
  //  If a non-success response status code is received, then nothing
  //  is streamed to the output file and the error response is returned by FullRequestNoBody.
  expectedStatus := 200;
  rest.SetResponseBodyStream(expectedStatus,True,fileStream);

  responseStr := rest.FullRequestNoBody('GET','/images/starfish.jpg');
  if (rest.LastMethodSuccess = False) then
    begin
      //  Examine the request/response to see what happened.
      WriteLn('response status code = ' + rest.ResponseStatusCode);
      WriteLn('response status text = ' + rest.ResponseStatusText);
      WriteLn('response header: ' + rest.ResponseHeader);
      WriteLn('response body (if any): ' + responseStr);
      WriteLn('---');
      WriteLn('LastRequestStartLine: ' + rest.LastRequestStartLine);
      WriteLn('LastRequestHeader: ' + rest.LastRequestHeader);
      Exit;
    end;

  WriteLn('downloaded starfish.jpg');

  //  Clear the response body stream previously set in the call to SetResponseBodyStream.
  rest.ClearResponseBodyStream();

  //  Download something else, but this time send the response body to bd.
  bd := TBinData.Create;
  success := rest.FullRequestNoBodyBd('GET','/images/penguins.jpg',bd);
  if (success = False) then
    begin
      //  Examine the request/response to see what happened.
      WriteLn('response status code = ' + rest.ResponseStatusCode);
      WriteLn('response status text = ' + rest.ResponseStatusText);
      WriteLn('response header: ' + rest.ResponseHeader);
      WriteLn('response body (if any): ' + bd.GetString('utf-8'));
      WriteLn('---');
      WriteLn('LastRequestStartLine: ' + rest.LastRequestStartLine);
      WriteLn('LastRequestHeader: ' + rest.LastRequestHeader);
      Exit;
    end;

  //  Save the contents of bd to a file.
  success := bd.WriteFile('qa_output/penguins.jpg');

  WriteLn('Success: ' + success);


  rest.Free;
  fileStream.Free;
  bd.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.