Send requests and receive replies. More...
Classes | |
| class | Authentication |
| HTTP authentication method for clients. More... | |
| class | BasicAuthentication |
| Basic HTTP authentication for clients. More... | |
| class | Authenticator |
| Client-side authentication. More... | |
| class | Client |
| HTTP user agent. More... | |
Client is the HTTP user agent. It holds one Request and one Reply, so the usual work is to fill the request, send it, and read the reply. The client opens a TCP connection to its host when a send needs one; there is no separate connect method.
The host is an Endpoint passed to a constructor or to setHost(). Asynchronous work needs an EventLoop, passed to a constructor or to setActive(), but the loop does not own the client. HTTPS is the same send and receive path after setSecure() has been given a Pt::Ssl::Context.
The request is request(). Set the URL, the method, query parameters and header fields before the send starts. The default method is GET. Write the request body with request().body(). The reply is reply() after a receive step has made it available.
Asynchronous receive is beginReceive() and endReceive(), and replyReceived() is emitted when a step has completed. endReceive() returns MessageProgress; if the reply is not finished, call beginReceive() again. Asynchronous send is beginSend() and endSend(), with requestSent() as the matching signal. A single beginReceive() is enough when the request is already complete and the caller only waits for the reply. Send first when the request has a body, when the body is chunked, or when several requests are pipelined.
A keep-alive header on the request asks for a persistent connection, which the server may still close. Pipelining needs that persistent connection, because several requests are sent before the matching replies are received. close() ends the connection. Leave it open only while the next request will reuse it; a later send on a closed or timed-out connection opens a new one.
send() and receive() are the blocking forms of the same exchange, and they complete the request or the reply on the calling thread.
When a reply is 401, Authenticator complements the request from realm credentials so the client can send it again. Basic authentication is built in, and other Authentication methods can be added.