cowboy/test/ws_SUITE_data/ws_subprotocol.erl

%% Feel free to use, reuse and abuse the code in this file.

-module(ws_subprotocol).

-export([init/2]).
-export([websocket_handle/2]).
-export([websocket_info/2]).

init(Req, Opts) ->
	[Protocol | _] = cowboy_req:parse_header(<<"sec-websocket-protocol">>, Req),
	Req2 = cowboy_req:set_resp_header(<<"sec-websocket-protocol">>, Protocol, Req),
	{cowboy_websocket, Req2, Opts, #{
		idle_timeout => 1000
	}}.

websocket_handle(_Frame, State) ->
	{ok, State}.

websocket_info(_Info, State) ->
	{ok, State}.
send resp_headers with websocket responses 2016-06-24 19:34:11 -06:00			`%% Feel free to use, reuse and abuse the code in this file.`

			`-module(ws_subprotocol).`

			`-export([init/2]).`
Remove Req from the Websocket interface After the switch to Websocket, we are no longer in a request/response scenario, therefore a lot of the cowboy_req functions do not apply anymore. Any data required from the request will need to be taken from Req in init/2 and saved in the handler's state. 2016-08-12 19:27:23 +02:00			`-export([websocket_handle/2]).`
			`-export([websocket_info/2]).`
send resp_headers with websocket responses 2016-06-24 19:34:11 -06:00
			`init(Req, Opts) ->`
			`[Protocol \| _] = cowboy_req:parse_header(<<"sec-websocket-protocol">>, Req),`
			`Req2 = cowboy_req:set_resp_header(<<"sec-websocket-protocol">>, Protocol, Req),`
Allow passing options to sub protocols Before this commit we had an issue where configuring a Websocket connection was simply not possible without doing magic, adding callbacks or extra return values. The init/2 function only allowed setting hibernate and timeout options. After this commit, when switching to a different type of handler you can either return {module, Req, State} or {module, Req, State, Opts} where Opts is any value (as far as the sub protocol interface is concerned) and is ultimately checked by the custom handlers. A large protocol like Websocket would accept only a map there, with many different options, while a small interface like loop handlers would allow passing hibernate and nothing else. For Websocket, hibernate must be set from the websocket_init/1 callback, because init/2 executes in a separate process. Sub protocols now have two callbacks: one with the Opts value, one without. The loop handler code was largely reworked and simplified. It does not need to manage a timeout or read from the socket anymore, it's the job of the protocol code. A lot of unnecessary stuff was therefore removed. Websocket compression must now be enabled from the handler options instead of per listener. This means that a project can have two separate Websocket handlers with different options. Compression is still disabled by default, and the idle_timeout value was changed from inifnity to 60000 (60 seconds), as that's safer and is also a good value for mobile devices. 2017-02-18 18:26:20 +01:00			`{cowboy_websocket, Req2, Opts, #{`
			`idle_timeout => 1000`
			`}}.`
send resp_headers with websocket responses 2016-06-24 19:34:11 -06:00
Remove Req from the Websocket interface After the switch to Websocket, we are no longer in a request/response scenario, therefore a lot of the cowboy_req functions do not apply anymore. Any data required from the request will need to be taken from Req in init/2 and saved in the handler's state. 2016-08-12 19:27:23 +02:00			`websocket_handle(_Frame, State) ->`
			`{ok, State}.`
send resp_headers with websocket responses 2016-06-24 19:34:11 -06:00
Remove Req from the Websocket interface After the switch to Websocket, we are no longer in a request/response scenario, therefore a lot of the cowboy_req functions do not apply anymore. Any data required from the request will need to be taken from Req in init/2 and saved in the handler's state. 2016-08-12 19:27:23 +02:00			`websocket_info(_Info, State) ->`
			`{ok, State}.`