Add middleware support

Middlewares allow customizing the request processing.

All existing Cowboy project are incompatible with this commit.
You need to change `{dispatch, Dispatch}` in the protocol options
to `{env, [{dispatch, Dispatch}]}` to fix your code.

1 files changed, 49 insertions, 0 deletions

diff --git a/src/cowboy_router.erl b/src/cowboy_router.erl
new file mode 100644
index 0000000..35c9396
--- /dev/null
+++ b/src/cowboy_router.erl
@@ -0,0 +1,49 @@
+%% Copyright (c) 2011-2013, Loïc Hoguin <[email protected]>
+%%
+%% 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 Routing middleware.
+%%
+%% Resolve the handler to be used for the request based on the
+%% routing information found in the <em>dispatch</em> environment value.
+%% When found, the handler module and associated data are added to
+%% the environment as the <em>handler</em> and <em>handler_opts</em> values
+%% respectively.
+%%
+%% If the route cannot be found, processing stops with either
+%% a 400 or a 404 reply.
+%%
+%% @see cowboy_dispatcher
+-module(cowboy_router).
+-behaviour(cowboy_middleware).
+
+-export([execute/2]).
+
+%% @private
+-spec execute(Req, Env)
+	-> {ok, Req, Env} | {error, 400 | 404, Req}
+	when Req::cowboy_req:req(), Env::cowboy_middleware:env().
+execute(Req, Env) ->
+	{_, Dispatch} = lists:keyfind(dispatch, 1, Env),
+	[Host, Path] = cowboy_req:get([host, path], Req),
+	case cowboy_dispatcher:match(Dispatch, Host, Path) of
+		{ok, Handler, HandlerOpts, Bindings, HostInfo, PathInfo} ->
+			Req2 = cowboy_req:set_bindings(HostInfo, PathInfo, Bindings, Req),
+			{ok, Req2, [{handler, Handler}, {handler_opts, HandlerOpts}|Env]};
+		{error, notfound, host} ->
+			{error, 400, Req};
+		{error, badrequest, path} ->
+			{error, 400, Req};
+		{error, notfound, path} ->
+			{error, 404, Req}
+	end.