Author Archives: Danijel Tkalčec

About Danijel Tkalčec

I was born on March 2nd 1975 in Croatia, in a small town called Čakovec. I have started learning programming in 1985 (at the age of 10) on a Commodore 64, then moved on to  Amiga 500 a few years later, then to an IBM compatible “AT/XP” PC in high-school (1989), where I’ve been widening my knowledge to other programming languages like dBase, Clipper, Assembly, Quick Basic, Turbo Prolog and Turbo Pascal. After my high-school years, I did my duty and served the Army, working in the Administration and writing custom Applications for Data Management in Turbo Pascal. Returning home, I’ve continued using Turbo Pascal to develop custom Applications for local Businesses. Then, Microsoft Windows started taking over the World of IBM compatible PCs, and the company behind Turbo Pascal has released “Delphi” for Windows. The rest is history.

RTC Portal: Discontinued and released on GitHub

RTC Portal was first released in July 2007 as a set of Delphi Projects using the RealThinClient SDK for communication and implementing a simple Remote Support solution with Remote Desktop Control, File Transfer and Multi-User Chat functionality. A few months later, RTC Portal was transformed into a set of visual components with full-featured Demo Projects, to make it easy for customers to update to later versions, without the need to make manual changes to their (usually modified) Projects. Unfortunately, because the market for such components is very small and the majority of customers didn’t seem to care much for updates, after 10 years of slow development and diminishing revenue, the last commercial RTC Portal update was released in June 2017 and RTC Portal was discontinued as a commercial component set for Delphi.

Today, RTC Portal is no longer available for purchase and there is NO SUPPORT available for using RTC Portal components or Demos, but the last version of RTC Portal VCL and RTC Portal X, compatible with RealThinClient SDK v9 and ready to be compiled for the Win32 platform using Delphi 7 – 10.2 can still be downloaded from GitHub:

-> RTC Portal VCL @ https://github.com/DTkalcec/portal
-> RTC Portal X @ https://github.com/DTkalcec/portalX

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RTC HTTP Server in 199 lines of code

Open a Text Editor of your choice, copy/paste the code below and save it as “MyHttpServer.dpr”.

program MyHttpServer;

{$APPTYPE CONSOLE}

uses
  SysUtils,

  rtcTypes,
  rtcSystem,
  rtcInfo,
  rtcConn,
  rtcDataSrv,
  rtcHttpSrv;

type
// This is our self-contained HTTP Server class ...
  TMyServer=class(TObject)
  protected
    HttpSrv:TRtcHttpServer;
    DataProv:TRtcDataProvider;

  public
    constructor Create(PortNumber:String='80'; IPVer:RtcIPV=rtc_IPVDefault);
    destructor Destroy; override;

    procedure DataProv_CheckRequest(Sender: TRtcConnection);
    procedure DataProv_DataReceived(Sender: TRtcConnection);

    procedure HttpSrv_ListenStart(Sender: TRtcConnection);
    procedure HttpSrv_ListenError(Sender: TRtcConnection; E:Exception);
    procedure HttpSrv_ListenStop(Sender: TRtcConnection);
    procedure HttpSrv_RequestNotAccepted(Sender: TRtcConnection);
    end;

constructor TMyServer.Create(PortNumber:String='80'; IPVer:RtcIPV=rtc_IPVDefault);
  begin
  // Create HttpServer and DataProvider components ...
  HttpSrv:=TRtcHttpServer.Create(nil);
  DataProv:=TRtcDataProvider.Create(nil);

  // Assign Server for our Data Provider ...
  DataProv.Server:=HttpSrv;

  // Assign Data Provider Events (handles Valid Requests) ...
  DataProv.OnCheckRequest:=DataProv_CheckRequest;
  DataProv.OnDataReceived:=DataProv_DataReceived;

  // Assign Server Events (handles the rest) ...
  HttpSrv.OnRequestNotAccepted:=HttpSrv_RequestNotAccepted;
  HttpSrv.OnListenStart:=HttpSrv_ListenStart;
  HttpSrv.OnListenStop:=HttpSrv_ListenStop;
  HttpSrv.OnListenError:=HttpSrv_ListenError;

  // Configure the Server ...
  HttpSrv.ServerPort:=PortNumber;
  HttpSrv.ServerIPV:=IPVer;
  HttpSrv.MultiThreaded:=True;

  // Start the Server listener ...
  HttpSrv.Listen();
  end;

destructor TMyServer.Destroy;
  begin
  // Stop the Server listener ...
  HttpSrv.StopListenNow();

  // Destroy the components ...
  HttpSrv.Free;
  DataProv.Free;
  end;

procedure TMyServer.DataProv_CheckRequest(Sender: TRtcConnection);
  begin
  // Check Request headers and "Accept" all Requests
  // we want to handle with our Data Provider ...
  with TRtcDataServer(Sender) do
    if (Request.Method='GET') and  // we only want "GET" requests
       (Request.ContentLength=0) then // ... with no content body
        if (Request.URI='/html') or
           (Request.URI='/json') or
           (Request.URI='/xml') or
           (Request.URI='/code') then
          Accept; // Accept the Request
  end;

procedure TMyServer.DataProv_DataReceived(Sender: TRtcConnection);
  var
    t:TRtcRecord;
  begin
  with TRtcDataServer(Sender) do
  // We will start processing the request only if
  // we have received the complee request content body ...
    if Request.Complete then
      if Request.URI='/html' then
        begin
        // We can use multiple "Write" calls
        // to prepare our HTML response ...
        Response.ContentType:='text/html';
        Write('<html><body>');
        Write('Your IP: '+PeerAddr+'<br>');
        Write('Your Port: '+PeerPort+'<br>');
        Write('Date & Time: <b>'+DateTimeToStr(Now)+'</b><br>');
        Write('Agent: <i>'+Request['User-Agent']+'</i><br>');
        Write('</body></html>');
        // All "Write" calls will be buffered,
        // RTC will calculate the "Content-Length" for us
        // and send the whole content body out as a single
        // Response - when we are finished with our event.
        end
      else
        begin
        // Using TRtcRecord to prepare our response Object ...
        t:=TRtcRecord.Create;
        try
          t.asText['agent']:=Request['User-Agent'];
          t.asText['ip']:=PeerAddr;
          t.asText['port']:=PeerPort;
          t.asDateTime['now']:=Now;
          if Request.URI='/json' then
            begin
            // Serialize to "JSON" ...
            Response.ContentType:='application/json';
            Write(t.toJSON);
            end
          else if Request.URI='/xml' then
            begin
            // Serialize to "XML-RPC" ...
            Response.ContentType:='text/xml';
            Write(t.toXMLrpc);
            end
          else if Request.URI='/code' then
            begin
            // Serialize to "Code" (RTC format) ...
            Response.ContentType:='text/plain';
            Write(t.toCode);
            end;
        finally
          t.Free;
          end;
        end
  end;

procedure TMyServer.HttpSrv_RequestNotAccepted(Sender: TRtcConnection);
  begin
  // Request wasn't accepted ...
  with TRtcDataServer(Sender) do
    begin
    // Send "404" status code back ...
    Response.Status(404,'Not Found');
    Response.ContentType:='text/plain';
    // Something to show in the Web Browser ...
    Write('Bad command.');
    // And ... Disconnect the Client.
    Disconnect;
    end;
  end;

procedure TMyServer.HttpSrv_ListenError(Sender: TRtcConnection; E: Exception);
  begin
  Writeln('Server Error: '+E.Message);
  end;

procedure TMyServer.HttpSrv_ListenStart(Sender: TRtcConnection);
  begin
  Writeln('Server started.');
  end;

procedure TMyServer.HttpSrv_ListenStop(Sender: TRtcConnection);
  begin
  Writeln('Server stopped.');
  end;

var
  MyServer:TMyServer;

begin
  try
    // Create and start our Server ...
    MyServer:=TMyServer.Create('80');
    try
      // Since this is a console application and our
      // Server is Multi-Threaded, we can do whatever
      // we want here. For simplicity reasons, we will
      // just use "ReadLn" to allow the Server to run
      // while we wait for the user to press <Enter>.

      Writeln('Press <Enter> to Quit ...');
      ReadLn;

      // User has pressed <Enter> - time to kill our Server.
    finally
      MyServer.Free;
      end;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

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Beware of the “As Administrator” option on Windows 8

Yesterday, I was preparing my Windows 8 Tablet PC for development and testing. As always, I went to use the “_clear.cmd” file from the “Lib” folder to delete old files before preparing a new package. But – wait! Windows 8 won’t let me run CMD files just like that! It blocked every time. So … to outsmart this new Windows 8 feature (I think it’s called “Screen-Scan”), I’ve simply selected “As Administrator” to run the “_clear.cmd” file with higher access rights.

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Posting code examples to RTC Forums

I’ve been burned by BB tags [b] and [i] more than once when posting code examples to RTC Forums, so I thought this would be worth mentioning here.

When posting to RTC Forums, you will be editing your text in raw format. This gives you full control over the look of your post by allowing you to directly insert special “BB” tags ([i] …[/i] for italic, [b]..[/b] for bold, [u]…[/u] for underlined text, and so on). You can also use the toolbar, which is visible directly above the text entry area (when composing your Forum post) to insert BB tags around your currently selected text.

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