Access to query strings (GET params) in user-defined endpoint handlers

[achimnol]

SockJS (the client side) allows adding query strings to the endpoint URL.
Here, currently there is no way to access them (e.g., request.GET) inside user-defined endpoint handler coroutines. I'd like to access them! 👀

In the code, sockjs seems to invoke the user-defined endpoint handler in SessionManager.acquire() and _acquire() methods, which is called by transports' process() coroutines. SockJSRoute and transport subclasses have access to the aiohttp's request object but it is not passed to the user-defined handler via acquire method chains.

Maybe it is not a good idea to pass the whole request object to user-defined handlers due to design principles such as "separation of concern", but still I think it would be nice to have access to GET parameters.

[asvetlov]

Please provide a Pull Reqest