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* Add Server::CustomRoute() for HTTP methods outside the built-in set parse_request_line validates the request method against a fixed whitelist and rejects anything else with 400 before routing runs. That blocks WebDAV, where PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK and UNLOCK are ordinary methods defined by RFC 4918, and it blocks extension methods such as UPnP's SUBSCRIBE. The need has been open since #847. Registering a handler is now what makes the server accept a method: svr.CustomRoute("PROPFIND", "/dav/:id", handler); Because custom methods go through the normal dispatch path, patterns work the way they do for Get() and friends, and the request body is available in req.body. Serving these methods through set_pre_routing_handler was never enough: the body has not been read at that point, so PROPPATCH and LOCK, which require one, could not be implemented at all. A HandlerWithContentReader overload is available too. The content reader gate in routing() also fires when a custom method carries no body, matching what expect_content() does unconditionally for POST/PUT/PATCH/DELETE, so a body-less PROPFIND (RFC 4918 treats one as allprop) reaches its handler instead of falling through to 404. Method names are validated as RFC 9110 tokens, and the ten built-in methods are refused. Seven of them are dispatched by the if/else chain in routing() before the custom tables are consulted, so a route registered for one could never fire; CONNECT, TRACE and PRI carry protocol-level meaning this library does not route. A refused registration makes is_valid() return false, so listen() fails rather than starting a server holding a handler that would never run. This is also why SSLServer::is_valid() now chains to Server::is_valid() instead of only checking ctx_. Servers that never call CustomRoute() keep the previous per-request cost: the built-in method set is checked first and short-circuits, and the custom lookup returns early on an empty map. * Add cookbook recipe for custom HTTP methods The CustomRoute() docs were a section inside S01, which pushed that page to 90 lines, the longest in the cookbook, and mixed a separate feature into a page about registering GET/POST/PUT/DELETE handlers. Move the section into its own recipe and give it room for the part that was missing: the OPTIONS handler returning DAV: and Allow, which WebDAV clients probe for before anything else. S01 goes back to 68 lines and keeps a pointer to the new page. The recipe is titled after the API rather than after WebDAV, and says outright that generating the 207 Multi-Status XML, interpreting Depth and managing locks are the reader's job. Routing the method is all the library does. S23 takes order 42, so the TLS, SSE and WebSocket recipes shift to 43-57. That only moves the sort key. Filenames, the T01/E01/W01 labels, the published URLs and every cross-reference are untouched.
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2.5 KiB
title, order, status
| title | order | status |
|---|---|---|
| W03. Handle Connection Close | 54 | draft |
A WebSocket ends when either side closes it explicitly, or when the network drops. Handle close cleanly, and your cleanup and reconnect logic stays tidy.
Detect a closed connection
When ws.read() returns ReadResult::Fail, the connection is gone — either cleanly or with an error. Break out of the loop and the handler will finish.
svr.WebSocket("/chat", [](const httplib::Request &req, httplib::ws::WebSocket &ws) {
std::string msg;
while (ws.is_open()) {
auto result = ws.read(msg);
if (result == httplib::ws::ReadResult::Fail) {
std::cout << "disconnected" << std::endl;
break;
}
handle_message(ws, msg);
}
// cleanup runs once we're out of the loop
cleanup_user_session(req);
});
You can also check ws.is_open() — it's the same signal from a different angle.
Close from the server side
To close explicitly, call close().
ws.close(httplib::ws::CloseStatus::Normal, "bye");
The first argument is the close status; the second is an optional reason. Common CloseStatus values:
| Value | Meaning |
|---|---|
Normal (1000) |
Normal closure |
GoingAway (1001) |
Server is shutting down |
ProtocolError (1002) |
Protocol violation detected |
UnsupportedData (1003) |
Received data that can't be handled |
PolicyViolation (1008) |
Violated a policy |
MessageTooBig (1009) |
Message too large |
InternalError (1011) |
Server-side error |
Close from the client side
The client API is identical.
cli.close(httplib::ws::CloseStatus::Normal);
Destroying the client also closes the connection, but calling close() explicitly makes the intent clearer.
Graceful shutdown
To notify in-flight clients that the server is going down, use GoingAway.
ws.close(httplib::ws::CloseStatus::GoingAway, "server restarting");
The client can inspect that status and decide whether to reconnect.
Example: a tiny chat with quit
svr.WebSocket("/chat", [](const auto &req, auto &ws) {
std::string msg;
while (ws.is_open()) {
if (ws.read(msg) == httplib::ws::ReadResult::Fail) break;
if (msg == "/quit") {
ws.send("goodbye");
ws.close(httplib::ws::CloseStatus::Normal, "user quit");
break;
}
ws.send("echo: " + msg);
}
});
Note: On a sudden network drop,
read()returnsFailwith no chance to callclose(). Put your cleanup at the end of the handler, and both paths — clean close and abrupt disconnect — end up in the same place.