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Remove the onrequest hook

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It was redundant with middlewares. Allows us to save a few operations
for every incoming requests.
This commit is contained in:
Loïc Hoguin 2014-09-24 14:39:17 +03:00
parent 25259671f5
commit aa4d86b81f
12 changed files with 86 additions and 260 deletions
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48
doc/src/guide/hooks.ezdoc
View file

@ -1,45 +1,7 @@
::: Hooks
Cowboy provides two hooks. `onrequest` is called once the request
line and headers have been received. `onresponse` is called just
before sending the response.
:: Onrequest
The `onrequest` hook is called as soon as Cowboy finishes fetching
the request headers. It occurs before any other processing, including
routing. It can be used to perform any modification needed on the
request object before continuing with the processing. If a reply is
sent inside this hook, then Cowboy will move on to the next request,
skipping any subsequent handling.
This hook is a function that takes a request object as argument,
and returns a request object. This function MUST NOT crash. Cowboy
will not send any reply if a crash occurs in this function.
You can specify the `onrequest` hook when creating the listener,
inside the request options.
``` erlang
cowboy:start_http(my_http_listener, 100,
[{port, 8080}],
[
{env, [{dispatch, Dispatch}]},
{onrequest, fun ?MODULE:debug_hook/1}
]
).
```
The following hook function prints the request object everytime a
request is received. This can be useful for debugging, for example.
``` erlang
debug_hook(Req) ->
erlang:display(Req),
Req.
```
Make sure to always return the last request object obtained.
Hooks allow the user to customize Cowboy's behavior during specific
operations.
:: Onresponse
@ -48,9 +10,9 @@ to the socket. It can be used for the purposes of logging responses,
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. If a reply
is sent, the hook MUST explicitly provide all headers that are needed.
Note that this function MUST NOT crash. 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.