Lazarus Pascal

REST through HTTP Proxy

See more REST Examples

Demonstrates how to connect through an HTTP proxy to make REST API calls. 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.AuthAws,
  Chilkat.Rest,
  Chilkat.Xml,
  Chilkat.Socket;

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

procedure RunDemo;
var
  success: Boolean;
  rest: TRest;
  socket: TSocket;
  bTls: Boolean;
  port: Integer;
  maxWaitMs: Integer;
  authAws: TAuthAws;
  responseXml: string;
  xml: TXml;

begin
  success := False;

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

  //  This example connects to a REST server through an HTTP proxy.
  //  It will connect to the Amazon AWS service for this example.
  rest := TRest.Create;
  socket := TSocket.Create;

  //  Set the HTTP proxy domain or IP address, and port.
  socket.HttpProxyHostname := '192.168.1.100';
  socket.HttpProxyPort := 8088;

  //  We want to tell the socket object that we're doing HTTP over the proxy connection.
  //  This is because an HTTP proxy used for other protocols (IMAP, SMTP, SSH, FTP, etc.) 
  //  can require some internal differences in behavior (i.e. how we do things).
  socket.HttpProxyForHttp := True;

  //  Other properties exist for specifying a proxy login, password, and authentication method (such as NTLM),
  //  but these are not used in this example.

  //  Connect through the HTTP proxy to the Amazon AWS server for the S3 service.
  bTls := True;
  port := 443;
  maxWaitMs := 5000;
  success := socket.Connect('s3.amazonaws.com',port,bTls,maxWaitMs);
  if (success <> True) then
    begin
      WriteLn('Connect Failure Error Code: ' + socket.ConnectFailReason);
      WriteLn(socket.LastErrorText);
      Exit;
    end;

  //  Use the proxied TLS connection:
  success := rest.UseConnection(socket,True);
  if (success <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  Provide AWS credentials for the REST call.
  authAws := TAuthAws.Create;
  authAws.AccessKey := 'AWS_ACCESS_KEY';
  authAws.SecretKey := 'AWS_SECRET_KEY';
  authAws.ServiceName := 's3';
  success := rest.SetAuthAws(authAws);

  //  List all buckets for the account...
  responseXml := rest.FullRequestNoBody('GET','/');
  if (rest.LastMethodSuccess <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  xml := TXml.Create;
  success := xml.LoadXml(responseXml);

  //  Show the full XML returned.
  WriteLn(xml.GetXml());

  //  Iterate over the buckets, showing each bucket name.
  success := xml.FindChild2('Buckets');
  if (xml.FirstChild2() = True) then
    begin
      WriteLn(xml.GetChildContent('Name'));
      while (xml.NextSibling2() = True) do
        begin
          WriteLn(xml.GetChildContent('Name'));
        end;

    end;
  //  Move the internal pointer back to the root node.
  xml.GetRoot2();


  rest.Free;
  socket.Free;
  authAws.Free;
  xml.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.