cndl strives to be an easy to embedd C++ webserver solution. One aim of this project was to have an as-close-to-flask-as-possible feel. Other aspects (like the handling of websockets) is roughly based on tornado's.
This is how the use of cndl looks:
#include <iostream>
#include <cndl/Route.h>
#include <cndl/Server.h>
#include <simplyfile/socket/Host.h>
using namespace std::literals::string_view_literals;
cndl::GlobalRoute a_route {R"(/(.+)/?)", [](cndl::Request const&, std::string_view arg) -> cndl::OptResponse {
// arg will have the value of the capture in the regex
return "<html><head></head><body><h1>cndl rocks</h1></body></html>"sv;
}, {.methods={"GET", "POST"}}};
struct : cndl::WebsocketHandler {
using Websocket = cndl::Websocket;
using Request = cndl::Request;
void onMessage([[maybe_unused]] Websocket& ws, [[maybe_unused]] AnyMessage msg) override {
if (std::holds_alternative<TextMessage>(msg)) {
std::cout << std::get<TextMessage>(msg) << std::endl;
}
ws.send(msg);
}
bool canOpen(Request const& request, [[maybe_unused]] int magic) {
std::cout << "socket connection request " << std::endl;
return true;
}
void onOpen([[maybe_unused]] Request const& request, [[maybe_unused]] Websocket& ws, [[maybe_unused]] int magic) {
std::cout << "socket connected " << request.header.url << std::endl;
}
void onClose([[maybe_unused]] Websocket& ws) override {
std::cout << "socket closed" << std::endl;
}
} echo_handler{};
int main()
{
cndl::Server& server = cndl::Server::getGlobalServer();
for (auto host : simplyfile::getHosts("localhost", "8080")) {
server.listen(host); // listen on localhost (ipv4 and ipv6 if available)
}
cndl::WSRoute wsroute{std::regex{R"(/(\d+)/)"}, echo_handler}; // route requests to /[number]/ to the echo_handler (onConnect will be called with the value of [number])
server.getDispatcher().addRoute(&wsroute); // hook the route to the server (you can have multiple routes fro a single endpoint)
server.loop_forever(); // run the server's ioloop (epoll). call this from as many threads as you like
return 0;
}A slightly more elaborate example can be found here. The example also employs qrqma and sargparse.