%% 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.