%% Feel free to use, reuse and abuse the code in this file.
%% @private
-module(error_hook_app).
-behaviour(application).
%% API.
-export([start/2]).
-export([stop/1]).
%% API.
start(_Type, _Args) ->
Dispatch = cowboy_router:compile([
{'_', []}
]),
{ok, _} = cowboy:start_http(http, 100, [{port, 8080}], [
{env, [{dispatch, Dispatch}]},
{onresponse, fun error_hook/4}
]),
error_hook_sup:start_link().
stop(_State) ->
ok.
error_hook(404, Headers, <<>>, Req) ->
Path = cowboy_req:path(Req),
Body = ["404 Not Found: \"", Path,
"\" is not the path you are looking for.\n"],
Headers2 = lists:keyreplace(<<"content-length">>, 1, Headers,
{<<"content-length">>, integer_to_list(iolist_size(Body))}),
cowboy_req:reply(404, Headers2, Body, Req);
error_hook(Code, Headers, <<>>, Req) when is_integer(Code), Code >= 400 ->
Body = ["HTTP Error ", integer_to_list(Code), $\n],
Headers2 = lists:keyreplace(<<"content-length">>, 1, Headers,
{<<"content-length">>, integer_to_list(iolist_size(Body))}),
cowboy_req:reply(Code, Headers2, Body, Req);
error_hook(_Code, _Headers, _Body, Req) ->
Req.
