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Diffstat (limited to 'guide/hooks.md')
| -rw-r--r-- | guide/hooks.md | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/guide/hooks.md b/guide/hooks.md index d4b520a..d7e6c72 100644 --- a/guide/hooks.md +++ b/guide/hooks.md @@ -48,7 +48,8 @@ or for modifying the response headers or body. The best example is providing custom error pages. Note that like the `onrequest` hook, this function MUST NOT crash. -Cowboy may or may not send a reply if this function crashes. +Cowboy may or may not send a reply if this function crashes. If a reply +is sent, the hook MUST explicitly provide all headers that are needed. You can specify the `onresponse` hook when creating the listener also. @@ -68,7 +69,10 @@ the default response otherwise. ``` erlang custom_404_hook(404, Headers, <<>>, Req) -> - {ok, Req2} = cowboy_req:reply(404, Headers, <<"404 Not Found.">>, Req), + Body = <<"404 Not Found.">>, + Headers2 = lists:keyreplace(<<"content-length">>, 1, Headers, + {<<"content-length">>, integer_to_list(byte_size(Body))}), + {ok, Req2} = cowboy_req:reply(404, Headers2, Body, Req), Req2; custom_404_hook(_, _, _, Req) -> Req. |