From 0dc063ab7d94edb37c61f821b5d8e4c2da7f8ff1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Tue, 30 Sep 2014 20:12:13 +0300 Subject: Improve handler interface and documentation This change simplifies a little more the sub protocols mechanism. Aliases have been removed. The renaming of loop handlers as long polling handlers has been reverted. Plain HTTP handlers now simply do their work in the init/2 callback. There is no specific code for them. Loop handlers now follow the same return value as Websocket, they use ok to continue and shutdown to stop. Terminate reasons for all handler types have been documented. The terminate callback is now appropriately called in all cases (or should be). Behaviors for all handler types have been moved in the module that implement them. This means that cowboy_handler replaces the cowboy_http_handler behavior, and similarly cowboy_loop replaces cowboy_loop_handler, cowboy_websocket replaces cowboy_websocket_handler. Finally cowboy_rest now has the start of a behavior in it and will have the full list of optional callbacks defined once Erlang 18.0 gets released. The guide has been reorganized and should be easier to follow. --- doc/src/manual/cowboy_loop_handler.ezdoc | 91 -------------------------------- 1 file changed, 91 deletions(-) delete mode 100644 doc/src/manual/cowboy_loop_handler.ezdoc (limited to 'doc/src/manual/cowboy_loop_handler.ezdoc') diff --git a/doc/src/manual/cowboy_loop_handler.ezdoc b/doc/src/manual/cowboy_loop_handler.ezdoc deleted file mode 100644 index 0811a9a..0000000 --- a/doc/src/manual/cowboy_loop_handler.ezdoc +++ /dev/null @@ -1,91 +0,0 @@ -::: cowboy_loop_handler - -The `cowboy_loop_handler` behaviour defines the interface used -by HTTP handlers that do not send a response directly, instead -requiring a receive loop to process Erlang messages. - -This interface is best fit for long-polling types of requests. - -The `init/3` callback will always be called, followed by zero -or more calls to `info/3`. The `terminate/3` callback will -always be called last. - -:: Types - -None. - -:: Callbacks - -: init({TransportName, ProtocolName}, Req, Opts) - -> {loop, Req, State} - | {loop, Req, State, hibernate} - | {loop, Req, State, Timeout} - | {loop, Req, State, Timeout, hibernate} - | {shutdown, Req, State} - -Types: - -* TransportName = tcp | ssl | atom() -* ProtocolName = http | atom() -* Req = cowboy_req:req() -* Opts = any() -* State = any() -* Timeout = timeout() - -Initialize the state for this request. - -This callback will typically be used to register this process -to an event manager or a message queue in order to receive -the messages the handler wants to process. - -The receive loop will run for a duration of up to `Timeout` -milliseconds after it last received data from the socket, -at which point it will stop and send a `204 No Content` reply. -By default this value is set to `infinity`. It is recommended -to either set this value or ensure by any other mechanism -that the handler will be closed after a certain period of -inactivity. - -The `hibernate` option will hibernate the process until it -starts receiving messages. - -The `shutdown` return value can be used to skip the receive -loop entirely. - -: info(Info, Req, State) -> {ok, Req, State} | {loop, Req, State} - | {loop, Req, State, hibernate} - -Types: - -* Info = any() -* Req = cowboy_req:req() -* State = any() - -Handle the Erlang message received. - -This function will be called every time an Erlang message -has been received. The message can be any Erlang term. - -The `ok` return value can be used to stop the receive loop, -typically because a response has been sent. - -The `hibernate` option will hibernate the process until -it receives another message. - -: terminate(Reason, Req, State) -> ok - -Types: - -* Reason = {normal, shutdown} | {normal, timeout} | {error, closed} | {error, overflow} | {error, atom()} -* Req = cowboy_req:req() -* State = any() - -Perform any necessary cleanup of the state. - -This callback will typically unregister from any event manager -or message queue it registered to in `init/3`. - -This callback should release any resource currently in use, -clear any active timer and reset the process to its original -state, as it might be reused for future requests sent on the -same connection. -- cgit v1.2.3