Is it possible to have dynamic routes in pion? - c++

Question

I'd like to use pion 5.0.6 as a small webserver in a VS2017 c++ project. For static routes I can use
add_resource("/my/static/route", <handler>)
I would need dynamic routes as well - like "/data/:id/info
How do I do this?

Answer 1

For those who may need it: I found a solution to add dynamic routing to the pion webserver. It requires smart router code I found at hxoht on github, and works the way that
all routes - static and dynamic - are set with httpd->add_resource(<url>, <handler);
a 404-handler has to be set with httpd->set_not_found_handler(<handler>); and is responsible for dispatching the dynamic routes to the handlers added above.
your webserver class must derive from pion::http::server in order to find the handler by name with httpd->find_request_handler(<url>, <handler>);
in your 404-handler, you use the Match::test(<dynamic-route>) method to detect a dynamic route - like in the following code fragment:
void handle_404(http::request_ptr& req, tcp::connection_ptr& con)
{
Route target;
Match dynamic = target.set(req->get_resource());
for (auto& route : dynamic_routes) // Our list of dynamic routes
{
if (dynamic.test(route)) // Does the url match the dynamic route pattern?
{
request_handler_t h;
if (find_request_handler(route, h))
{
auto name = get_param_name(route); // e.g. /a/:b -> "b"
value = dynamic.get(name); // Save value in string or map<name, value>
h(req, con); // Call original handler with value set properly
return;
}
}
}
// If no match then return a 404.
http::response_writer_ptr w(http::response_writer::create(con, *req,
boost::bind(&tcp::connection::finish, con)));
http::response& res = w->get_response();
res.set_status_code(http::types::RESPONSE_CODE_NOT_FOUND);
res.set_status_message(http::types::RESPONSE_MESSAGE_NOT_FOUND);
w->send();
}
For using the pion webserver in a multi-threaded way, I would store the parsed value inside the request object, which would be derived from pion::http::request.
This would work for Windows and Linux :)