Oh! Forget guys my message above!

The calling of Python code from C++ plugin in @kbar 's advice does the trick!

If someone from the future who will read this thread will need the code example, I just use the code snippet from here: https://developers.maxon.net/docs/Cinema4DCPPSDK/html/page_maxonapi_python.html

and feed to it this code:

// call it from somewhere
String code = "import c4d\nimport maxon\nimport os    ";
        code+= "\n\nprint(f'This is simple message')";
        code += "\nos.rename('C:/Code/sdk/plugins/myPlugin/myPlugin.xdl64', 'C:/Code/sdk/plugins/myPlugin/old_myPlugin.old')"; 
        
ExecutePythonScript(code, GetActiveDocument());

this is what I got:
sslConnection.DoHandShake failed while connecting to https://www.mysite.com/myfile.xdl64: SSL_do_handshake returned error: SSL_ERROR_SSL (certificate verify failed Certificate Information: not available)

I have the same problem (C++, R21, Win10).
this code:

const maxon::Url url("https://www.mysite.com/myfile.xdl64"_s);
if (url.IoDetect() != maxon::IODETECT::FILE)
        return;

returns the ssl certificate error in debug console.

The same code works in R23, R24, R25 (R22 did not check yet).

Hi @ferdinand , thank you for your answer.
I've fixed the problem via a simple disabling "threat warnings as errors" to "No" in Project Properties/C++/General.

It compiles now, which is cool, but is pretty strange, because I did it early before the asking here.

About the error reasons I still don't know what was causing the problem. Yes, I checked the console output. The error is from there with no more details. Also this c2220 error appears only in VS-project created for a R24 version of Cinema 4D. The same code has no problem in VS-projects for a R23 and R25. Literally: I just copy and paste the same code from here to here. Every project - with the same project settings, same additional libraries dependencies and same C++ version (17).

So in case someone comes across this problem, just disable the "Threat warnings as errors" in your project properties. It should help.

Hello.
I have a problem with compiling the plugin for a R24. The same code which compiles and is performed perfectly for R23 and R25, in R24 when I try to build the project throws an error.
The error is: "error C2220: the following warning is treated as an error".
The source of an error is almost random. The codeline which throw an error for R24, does not do it for R23 and R25.
For example the line like so:

C4DGadget* const textA = AddEditText(3000, BFH_SCALEFIT, 0, 10, 0);

If I delete it at all and hit the "build project", the same error appears in entirely another place:

for (Int32 i = 0; i < linkBoxesIDs.size(); ++i) {}

if I delete it too, the error starts to appear another place:

BaseContainer* data = op->GetDataInstance();

etc.

I've check the version of the project tool, sdk(the same as a version of c4d) and my Visual Studio (it is 2019).

The plugin file which was compiled for a R23, shows up in R24. And I would use it in a R24 version of Cinema 4D, but my plugin uses some python code from a C++ and due to some differences in include files for the python in r23 and r24, this python code does not work in R24. So I need to recompile the plugin for the correct version.

Is this a known issue?

Oh! Forget guys my message above!

The calling of Python code from C++ plugin in @kbar 's advice does the trick!

If someone from the future who will read this thread will need the code example, I just use the code snippet from here: https://developers.maxon.net/docs/Cinema4DCPPSDK/html/page_maxonapi_python.html

and feed to it this code:

// call it from somewhere
String code = "import c4d\nimport maxon\nimport os    ";
        code+= "\n\nprint(f'This is simple message')";
        code += "\nos.rename('C:/Code/sdk/plugins/myPlugin/myPlugin.xdl64', 'C:/Code/sdk/plugins/myPlugin/old_myPlugin.old')"; 
        
ExecutePythonScript(code, GetActiveDocument());

@kbar thanks for advice.
Do you rename and delete in your case the .xdl64 file? Or the .pyp/.pypv ?

Actually, after a lot of debugging I can see that the C4DPL_ENDPLUGINACTIVITY2 is called before the plugin registration destroyed. Contrary to the statement here: https://developers.maxon.net/docs/Cinema4DCPPSDK/html/group___c4_d_p_l___m_e_s_s_a_g_e_s.html#ga76cde585e6d5b223b10edcb6591a60ac
After C4DPL_ENDPLUGINACTIVITY2 case sends its end
we go to the c4d_pmain.cpp, where c4d starts to free the plugin resources:

C4D_MAIN
{
	static Int32 init_count = 0;

	switch (action)
	{
case C4DPL_END:
			init_count -= 1;
			if (init_count == 0)
			{
				PluginEnd();
				FreeResource();
				DeleteObj(path_storage);
			}
			return 1;

So before that last line it is impossible to replace the plugin file. But after that line we don't go back anymore to our plugins functions where "replace" function exists.

Maybe I am trying to do it entirely in a wrong way? And there is more smart way how others do the update system for their plugins?

Hi @ferdinand
I've tried your advice with renaming the file. But it is still the same : (
Am I doing it in a way it is intended?
(this func is called when the C4DPL_ENDPLUGINACTIVITY2 occurs )

Bool WriteUpdates()
{ 
	Filename old_fn;	 
	old_fn = GeGetPluginPath();
	old_fn += Filename{ "firstplugin.xdl64" };
	AutoAlloc<BaseFile> file;
	if (file == nullptr)
		return false;
                               // if I change FILEOPEN::READ to WRITE, I get the error 
	if (!file->Open(old_fn, FILEOPEN::READ , FILEDIALOG::ANY, BYTEORDER::V_INTEL, MACTYPE_CINEMA, MACCREATOR_CINEMA))
		return false;

	Filename new_fn;
	new_fn = GeGetPluginPath();
	new_fn += Filename{ "firstplugin.old" };
	file->WriteFilename(new_fn); // here I got an error

        // After that I`ve tried this line (with changing Alloc to Hyperfile), but also got an error
        GeFKill(old_fn, GE_FKILL_FORCE); 
 
	return true;
}

Thank you @ferdinand . Sorry for my confused explanation, but yes, you understand perfectly correctly: I need to update the plugin file on the clients machine when the update-file is ready on my web-server.
Right now I am able to send the message into my plugin instance from my server. My plugin listening my web-server and in some moment receives the message that the update is available. When plugin instance got this message, it starts the code function quoted above (i.e download the new .xdl64 file).

So I can build the updates system through the notification to the client with the request to install this update manually. But I want to make it more easily and unnoticed by the client.

Right now I've tried to simple replace my plugin-file (.xdl64) during C4DPL_ENDPLUGINACTIVITY2 via

std::filesystem::copy_file(from, to, overwrite_existing);

But I got the error and had not success.
It seems that the .xdl64 file is still in use when C4DPL_ENDPLUGINACTIVITY2 make a call. During debugging I just got an error from <filesystem> and "plugin.xdl64" remain the same, which is understandable if the file is still in use:)

So I will try your advice with the storing the data from new one .xdl64 to a Char*. But I have a doubt will it help if the .xdl64 is still busy during C4DPL_ENDPLUGINACTIVITY2.

Thank you again @ferdinand .

Hello @ferdinand
Thank you for a such detailed answer.
I've pasted your code in my project but received the error during compiling when I call SomeFunction() in another place of project.

So I've changed it little bit to this and now it works perfectly:

void DownloadUpdates()
{
    iferr_scope_handler
    {
        GePrint(err.GetMessage());
        return;
    }; 
     
    const maxon::Url url("https://mysite.com/somefile.jpg"_s);
  
    const maxon::UrlScheme scheme = url.GetScheme();
    const maxon::Bool isHTTP = scheme == maxon::URLSCHEME_HTTP;
    const maxon::Bool isHTTPS = scheme == maxon::URLSCHEME_HTTPS;

    if (isHTTP || isHTTPS)
    {
        const maxon::InputStreamRef inputStream = url.OpenInputStream() iferr_return;
        const maxon::Int length = inputStream.GetStreamLength() iferr_return;

        maxon::BaseArray<maxon::Char> data;
        data.Resize(length) iferr_return;

        inputStream.Read(data) iferr_return;
        inputStream.Close() iferr_return;

          
        const maxon::Url someUrl(GeGetPluginPath().GetString()); 
        const maxon::Url anotherUrl = (someUrl + url.GetName()) iferr_return;
        const maxon::OutputStreamRef outputStream = anotherUrl.OpenOutputStream() iferr_return;

        outputStream.Write(data) iferr_return;
        outputStream.Close() iferr_return;

    }
}  

Thank you.

One last question: does the way to rewrite the .xdl64 plugin file during Cinema 4D is going to work exist? (OR at least replace it after Cinema 4D was closed?)
Or I will be needed to ask user to install updates manually?