global error handler for http_listener

[art-in]

hi, there's handler::handle_error, but i don't see where it's used.

is there way to set global error handler, so i dont need to try/catch all handlers to log exceptions? otherwise looks like http_listener just swallows exception and replies with 500.

[Meenapintu]

HI @artin-phares handler::handle_error designed to use as a global error handler but it's not used right now.

Anyway Global error handler can be used like

 void handler::handle_get(http_request message) {
    ucout <<  message.to_string() << endl;
    auto paths = http::uri::split_path(http::uri::decode(message.relative_uri().path()));

    message.relative_uri().path();
	//Dbms* d  = new Dbms();
    //d->connect();

      concurrency::streams::fstream::open_istream(U("static/index.html"), std::ios::in).then([=](concurrency::streams::istream is)
    {
        message.reply(status_codes::OK, is,  U("text/html"))
		.then([](pplx::task<void> t)
		{
			error_handle(t);
	});
    }).then([](pplx::task<void>t)
	{
		 error_handle(t);
	});

    return;

Thanks @artin-phares , I'll update it.

[art-in]

well, that doesn't look good to me..

the idea is to keep error handler away from request handlers as much as possible.

i'm currently using handle wrapper and lambdas like this:

void handle(web::http::http_request req, std::function<void()> handler) {
  try {
    handler();
  } catch (std::exception &e) {
    ucerr << "Failed to handle request: " << e.what() << std::endl;
    ucerr << req.to_string() << std::endl;
    throw e;
  }
}

void handler::handle_post(web::http::http_request req) {
  handle(req, [&] {
    // ... do stuff ...
    req.reply(web::http::status_codes::OK);
  });
};

void handler::handle_get(web::http::http_request req) {
  handle(req, [&] {
    // ... do stuff ...
    req.reply(web::http::status_codes::OK, resp);
  });
};

which doesn't look good either.

what i really want to do is something like this:

m_listener.set_error_handler(&handle_error);

handle_error(web::http::http_request req, std::exception e) {
  // handle exception thrown from any registered handler of this listener.
  // reply with custom status code/text, log, etc.
}

[Meenapintu]

m_listener.set_error_handler(&handle_error); is a good idea. I"m not aware that there is a such functionality or not as i'm not working on it frequently .

I think you have to deep dive and figure out.