Keesver

Update: It works when I turn off the Firewall on my internet router (one step forward). Apparently there are other ports/channels needed to make a HTTPProxy work? Investigating......

There is no error, the call from the remote server back into the client simply does not reach it's destination. The remote server does receive a HTTPBeforeCommand event, this line is being called on the server: 

Writeln('Command redirected to DESTINATION: ' + dest_ip + ' - ' +  dest_port.ToString);

The connection between client and server seems to be working. When I use telnet to connect to the server, I do get a response from the server when I execute the 'HELP' command. Similar the call to SendCmd('DEST') in our client returns '200 OK'. Also 'netstat' shows an active connection between client and server.

Maybe my question is: what do I need more that an active (TCP) connection between client and server? 

Does the HTTP Proxy server requires additional channels to be opened to make this work? Or should the single channel suffice?

Hello,

We want to add remote support to our application and for this we want to use two idHttpProxyServer's chained together. The first server resides on our public server, the second instance resides on the customers network. This is the code we are using:

public server:

constructor TRemoteServer.Create(IP: string; Port: Integer);
begin
  IdHTTPProxyServer1 := TIdHTTPProxyServer.Create(nil);
  IdHTTPProxyServer1.ReuseSocket := rsTrue;
  IdHTTPProxyServer1.DefaultPort := Port;

  IdHTTPProxyServer1.OnHTTPBeforeCommand := HTTPBeforeCommandHandler;

  var handler := IdHTTPProxyServer1.CommandHandlers.Add;
  handler.Command := 'DEST';
  handler.HelpSuperScript := 'Sets caller as a DESTINATION for remote support (usage DEST PIN URL)';
  handler.OnCommand := DEST_Handler;

  if (IP <> '') and (Port <> 0) then
  begin
    Writeln('Starting server, binding to: ' + IP + '-' + Port.ToString);
    var bind := IdHTTPProxyServer1.Bindings.Add;
    bind.IP := IP;
    bind.Port := Port;
    bind.ReuseSocket := rsTrue;
  end else
    Writeln('Starting server, default binding');

  IdHTTPProxyServer1.Active := True;

  Writeln('Server running, listening on: ' + IdHTTPProxyServer1.Bindings[0].IP + ' - ' + IdHTTPProxyServer1.Bindings[0].Port.ToString);
end;

procedure TRemoteServer.DEST_Handler(ASender: TIdCommand);
begin
  Writeln(ASender.RawLine);
  dest_ip := ASender.Context.Binding.PeerIP;
  dest_port := ASender.Context.Binding.PeerPort;
  dest_pin := ASender.Params[0];
  dest_url := ASender.Params[1];
  Writeln('Address: ' + dest_ip + ' - ' + dest_port.ToString);
end;

procedure TRemoteServer.HTTPBeforeCommandHandler(AContext: TIdHTTPProxyServerContext);
begin
  if dest_ip <> '' then
  begin
    Writeln('Command redirected to DESTINATION: ' + dest_ip + ' - ' +  dest_port.ToString);

    var tempIO := TIdIOHandlerStack.Create(AContext.OutboundClient);
    tempIO.ReuseSocket := rsTrue;
    // tempIO.BoundIP := '10.0.2.4'; //IdHTTPProxyServer1.Bindings[0].IP;
    tempIO.BoundPort := 443; // IdHTTPProxyServer1.Bindings[0].Port;

    var tempProxy := TIdConnectThroughHttpProxy.Create(AContext.OutboundClient);
    tempProxy.Enabled := True;
    tempProxy.Host := dest_ip;
    tempProxy.Port := dest_port;
    tempIO.TransparentProxy := tempProxy;

    AContext.OutboundClient.IOHandler := tempIO;
  end;
end;

Client code:

procedure TForm1.ConnectToRemote(Connection: string);
begin
  HTTPProxyServer.Active := False;
  IdTCPClient1.Disconnect;

  IdTCPClient1.Host := <SERVER IP/URL>; //Connection.Split([':'])[0];
  IdTCPClient1.Port := <SERVER PORT>; // Connection.Split([':'])[1].ToInteger;
  IdTCPClient1.Connect;

  // Tell server we are there
  IdTCPClient1.SendCmd('DEST 4444 https://abc.com');

  HTTPProxyServer.Bindings.Clear;
  var bind := HTTPProxyServer.Bindings.Add;
  bind.IP := IdTCPClient1.Socket.Binding.IP;
  bind.Port := IdTCPClient1.Socket.Binding.Port;
  bind.ReuseSocket := rsTrue;

  HTTPProxyServer.Active := True;
end;

This setup works when we run both server and client on the same computer. However, when we put the server on a remote computer, it does not work. 

Should this work, or do we need other means to make this happen?

Thanks and regards,

Kees

ok, will do.

I was trying to use FDBatchMove + FDBatchMoveSQLWriter to import a table from MSSql into Interbase. The internal table generator uses 'Int64' for such fields, am I using the wrong generator?

Greetings,

Kees

Which data type should be used for Int64 values?

I tried Int64 and bigint, both return an error:

create table Test(ID Int64)

create table Test(ID bigint)

Error message:

Project IBTest.exe raised exception class EIBNativeException with message '[FireDAC][Phys][IB]Dynamic SQL Error
SQL error code = -607
Invalid command
Specified domain or source column does not exist'.

Thanks

WeekOfTheYear is working. I was looking for something like DateTimeToString which supports displaying dates like above using week numbers (aka "2009-W01")

According to this document ISO 8601 - Wikipedia
 

Monday 29 December 2008 is written as "2009-W01-1" when a week number is used.

As you can see, instead of 2008, the value 2009 is shown. What date formatting function supports this in Delphi?

Thanks

Can you explain why supports/queryinterface can't be used?

Hello,

We are looking at safely handling queued calls. The problem is that under some circumstances the object used inside the queued method is freed before the method gets executed. This raises an exception. Can we use this construct to fix it:

type
  ITest = interface
    ['{10DD63EA-490E-45D5-9250-72AEB1FF6D19}']
    function GetName: string;
    procedure SetName(const Value: string);
  end;

  TTest = class(TInterfacedObject, ITest)
  protected
    FName: string;

    function GetName: string;
    procedure SetName(const Value: string);
  end;

  TObjectWithTest = class
  private
    FTest: ITest;

  public
    constructor Create(const AInterface: ITest);
    procedure   QueueCallSafe([weak]AInterface: ITest);
    function GetTest: ITest;
  end;

implementation

procedure TObjectWithTest.QueueCallSafe([weak]AInterface: ITest);
begin
  TThread.ForceQueue(nil, procedure begin
    if AInterface = nil then
      ShowMessage('nil') else
      ShowMessage('not nil');
  end);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  var obj := TObjectWithTest.Create(TTest.Create);
  obj.QueueCallSafe(obj.GetTest);
  
  // Free object --> [weak] reference will be cleared (no exception!!)
  obj.Free;
end;

We are using EV (extended validation) code signing certificates to add trust, this should prevent Windows from asking additional confirmation when installing our software. In addition, when the certificate is renewed, trust statistics are kept because the new certificate is recognized as being the same as the 'old' one. Requesting such a certificate requires extra steps during the certification process.
(I can send you an installation url if you want to see how this works out)

This seems to be related: 6546 – EglCreateWindowSurface failed with error 12297 (0x3009) (xamarin.github.io)

Thanks everyone for your comments. Enough information to look into.

The Delphi language guide looks like a good starting point, this is something the person can do by themselves.

@David: your comments include a good list of topics that need to be touched in the learnings. 

Greetings,

Kees Vermeulen

VCL and FMX and Oxygene (much of our code is reused in our web application using WebAssembly)

New to Delphi, they have completed their bachelor's degree in software engineering.

Hello,

We extended our team with new (inexperienced) developers. What would be the best way to teach them Delphi?

Greetings, Kees

MadExcept includes the name of the Delphi compiler in their reports. I checked their code, they use a defines to get to the name of the compiler:

{$ifdef ver340}
// 'compiled with', 'Delphi 10.4 Sydney'
{$endif}

I can remember that Remy Lebeau posted some messages on this.  Searching for "openssl android remy" will bring you to StackOverflow.

We run on Azure...

We are preparing to release our software using Thinfinity as an alternative to the desktop version. We did some tests and this showed it worked pretty good. We do want to change our application to make it look more 'web' alike. This means hiding the menu for example. Can't tell yet how performant it will be. You do need a server capable of handling the number of concurrent users of your application though.

We were told RDS licenses are not required because Thinfinity does not use the RDS services (which I can confirm after running multiple sessions on the same server without such license). I can't say if Microsoft agrees on this....

Got my copy as well, thanks!

A 'trick' we used to improve the behavior while moving windows between monitors was to create a bitmap when the user starts dragging and use this image while dragging. It works very good and only when the user releases the mouse you need to do rescaling.

I think this should be TThread.Synchronize because the code needs to wait for the result.

Hello,

We are looking for an FMX developer, experience required. We are located in the Netherlands, but working remote is possible. This is a long term project for at least 3 days per week.

Thanks, Kees Vermeulen, A-dato

2 hours ago, Fr0sT.Brutal said:

Is it possible to embed this engine into Delphi app?

Yes, see https://github.com/Coldzer0/QuickJS-Pascal

Looks like a promising solution too.

15 hours ago, Bob Devine said:

@Keesver We have a private WeMe group and some more recent updates. Email me on gmail.com (name at the end of this post). The deal is that I confirm with Alexander that you're a registered user then you can get access. 

 

Cheers, Bob (rlsdevine@)

Thanks for your reply. Problem is that we are not a 'registered user' of paxCompiler.

We are investigating possibilities of adding scripting to our application and paxCompiler seems to have all the right specifications. Maybe someone is willing to sell their license to us?

I have contacted Apex but got no reply (yet).