%% Copyright (c) 2013, Loïc Hoguin %% %% Permission to use, copy, modify, and/or distribute this software for any %% purpose with or without fee is hereby granted, provided that the above %% copyright notice and this permission notice appear in all copies. %% %% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES %% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF %% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR %% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES %% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN %% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF %% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. %% @doc Behaviour for middlewares. %% %% Only one function needs to be implemented, execute/2. %% It receives the Req and the environment and returns them %% optionally modified. It can decide to stop the processing with %% or without an error. It is also possible to hibernate the process %% if needed. %% %% A middleware can perform any operation. Make sure you always return %% the last modified Req so that Cowboy has the up to date information %% about the request. -module(cowboy_middleware). -type env() :: [{atom(), any()}]. -export_type([env/0]). -callback execute(Req, Env) -> {ok, Req, Env} | {suspend, module(), atom(), [any()]} | {halt, Req} | {error, cowboy:http_status(), Req} when Req::cowboy_req:req(), Env::env().