Pascal (Lazarus/Delphi)

Send a Staged Form-URL-Encoded REST Request

Demonstrates Rest.SendReqFormUrlEncoded, which sends an application/x-www-form-urlencoded request whose body is built from the query parameters added to the object.

Background. The staged request model separates sending from reading: a SendReq method transmits the request, ReadResponseHeader reads the status line and headers, and a ReadResp method reads the body. This gives fine control over large or streamed messages compared with the single-call full-request methods.

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Pascal (Lazarus/Delphi)

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.Rest;

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

procedure RunDemo;
var
  success: Boolean;
  rest: TRest;
  bTls: Boolean;
  bAutoReconnect: Boolean;
  statusCode: Integer;
  responseBody: string;

begin
  success := False;

  rest := TRest.Create;
  bTls := True;
  bAutoReconnect := True;
  success := rest.Connect('example.com',443,bTls,bAutoReconnect);
  if (success = False) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  The form body is built from the query parameters added to the object.
  rest.AddQueryParam('username','alice');
  rest.AddQueryParam('action','login');

  //  Send the application/x-www-form-urlencoded request.
  success := rest.SendReqFormUrlEncoded('POST','/api/login');
  if (success = False) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  After sending, read the response status line and header fields.  The return value is the HTTP
  //  status code, or -1 if no response was received.
  statusCode := rest.ReadResponseHeader();
  if (statusCode < 0) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;
  WriteLn('Response status code: ' + statusCode);

  //  Read the response body as text.
  responseBody := rest.ReadRespBodyString();
  if (rest.LastMethodSuccess = False) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;
  WriteLn(responseBody);


  rest.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.