Casablanca - prevent console output

Question

Hi,

I am developing a console application using Casablanca and sometimes, when an error occurs, the library prints on my console window. Is there any way to prevent this, or a way to disable console outputs?

Answer 1

This is clearly an irritating "feature," one we're addressing in the upcoming refresh.

For now, it should be fixable by setting the default log object to 'nullptr,' using actors::log::set_default(nullptr); do this at the beginning of your application (in main() on the client, or on_initialize() on the server).

Caveat: I can't say that we have tested this a lot, but all the code does seem to be checking for NULL properly.

Niklas

Answer 2

I tried to disable the outputs by setting the default log to 'nullptr', but it didn't work for me. When I try to access an invalid url, for example, it prints on the console window "Error 12007: Error in: WinHttpSendRequest: The DNS server could not by Resolved" 

The same thing occurs when I start the TrivialServer example. It prints: "Registering the default server API Windows HTTP Server", and then, "Registering to listen for HTTP requests at http://localhost:4711/trivial..."

Here is the code:

int main(int argc, char* argv[])
{
actors::log::set_default(nullptr); // Try to prevent console outputs

http_listener::create("http://localhost:4711/trivial", [](http::http_request message)
    {
        message.reply(http::status_codes::OK, "Hello World!");
        //std::cout << "Served a request..." << std::endl;
    })
    /* Prevent Listen() from returning until user hits 'Enter' */ 
    .listen([]() { fgetc(stdin); }).wait();

    return 0;
}

Am I doing something wrong?

---

Marcelo

Answer 3

Nope, you're not doing anything wrong. This is a bug. I've stepped through the code and it fails.

The only workaround for the bug that I can think of is to implement a log class (derived from actors::_Log, overriding the two post() functions) that does nothing when given a string to post. Then, pass a pointer (or shared pointer) to an instance of this class to the set_default() function.

Good thing you found this and reported it before we refresh (we're hoping that will happen this week)!

Niklas

Answer 4

The proposed workaround worked nicely. 

The console outputs stopped and now I can store the messages into a log file.
Perfect.

class Log : public actors::_Log

{

private:

virtual void post(actors::log_level level, const std::string &message);
virtual void post(actors::log_level level, int code, const std::string &message);
virtual void post(actors::log_level level, const std::wstring &message);
virtual void post(actors::log_level level, int code, const std::wstring &message);

};

void Log::post(actors::log_level level, const std::string &message) { /* Here you can store the message into a log file */ }
void Log::post(actors::log_level level, int code, const std::string &message) { /* Here you can store the message into a log file */ }
void Log::post(actors::log_level level, const std::wstring &message) { /* Here you can store the message into a log file */ }
void Log::post(actors::log_level level, int code, const std::wstring &message) { /* Here you can store the message into a log file */ }

Thanks for the help.

---

Marcelo

Answer 5

BTW, we have an internal file log implementation that maybe we should make public...

I've checked in afix to the nullptr problem, so it will definitely be in the refresh.

Niklas