Responder Class Reference

#include <Pt/Http/Responder.h>

Handles one HTTP request and writes the reply. More...

Inherited by WebSocketResponder.

Public Member Functions
	Responder (Service &s)
	Construct with service.
virtual	~Responder ()
	Destructor.
Service &	service ()
	Returns the service for which to respond.
const Service &	service () const
	Returns the service for which to respond.
void	beginRequest (Request &request, Reply &reply, System::EventLoop &loop)
	Called when the request header was received.
void	readRequest (Request &request, Reply &reply, System::EventLoop &loop)
	Called when request body data was received.
void	beginReply (const Request &request, Reply &reply, System::EventLoop &loop)
	Called when request is complete.
void	writeReply (const Request &request, Reply &reply, System::EventLoop &loop)
	Write responding reply.

Protected Member Functions
virtual void	onBeginRequest (Request &request, Reply &reply, System::EventLoop &loop)=0
	Called when the request header was received.
virtual void	onReadRequest (Request &request, Reply &reply, System::EventLoop &loop)=0
	Called for each chunk of the request body.
virtual void	onBeginReply (const Request &request, Reply &reply, System::EventLoop &loop)=0
	Called when request is complete.
virtual void	onWriteReply (const Request &request, Reply &reply, System::EventLoop &loop)=0
	Write responding reply.
void	setReady (bool isFinished)
	Sets whether the current step is complete.
void	setFinished (bool isFinished)
	Sets whether the exchange is finished.

Detailed Description

Responder is the per-exchange handler in the server model. A Service creates it for a mapped request and releases it when the reply has been sent. Derive from it and implement the four callbacks, which the server calls in order.

onBeginRequest() runs when the request header is available, so the responder can inspect fields and prepare the reply. onReadRequest() runs for each chunk of the request body, and may be called more than once. onBeginReply() runs when the request is complete and the reply should start. onWriteReply() runs when a previous Reply::beginSend(false) needs another chunk of the reply body, which is how a large reply is written in chunked encoding.

Finish the reply with Reply::beginSend() and the completion flag set to true. That call may be made from an earlier callback, in which case the remaining callbacks are skipped and the rest of the request is ignored. service() is the service that created this responder.

The example is a responder that ignores the request body and writes a fixed reply. beginSend(true) completes the reply in onBeginReply(), so onWriteReply() stays empty.

class HelloResponder : public Pt::Http::Responder
{
    public:
        explicit HelloResponder(Pt::Http::Service& s)
        : Pt::Http::Responder(s)
        {}
 
    protected:
        virtual void onBeginRequest(Pt::Http::Request& request,
                                    Pt::Http::Reply& reply,
                                    Pt::System::EventLoop& loop)
        {}
 
        virtual void onReadRequest(Pt::Http::Request& request,
                                   Pt::Http::Reply& reply,
                                   Pt::System::EventLoop& loop)
        {}
 
        virtual void onBeginReply(const Pt::Http::Request& request,
                                  Pt::Http::Reply& reply,
                                  Pt::System::EventLoop& loop)
        {
            reply.body() << "Hello World!";
            reply.beginSend(true);
        }
 
        virtual void onWriteReply(const Pt::Http::Request& request,
                                  Pt::Http::Reply& reply,
                                  Pt::System::EventLoop& loop)
        {}
};