[99s-extend] REST handler failure

Ivan uemlianin ivan at llaisdy.com
Wed Oct 30 16:27:15 CET 2013


Instead of <<"this body ignored">> can you return the atom halt?

#dontevenhaveanyofmycodewithme:(

Ivan

--
festina lente


On 30 Oct 2013, at 15:58, Daniel Goertzen <daniel.goertzen at gmail.com> wrote:

> Well, this sort of works.  I tried this in the response handler:
> 
>             {ok, Req2} = cowboy_req:reply(404, [] , <<"this is the body that gets used">>, Req1),
>             {<<"this body gets ignored">>, Req2, State};
> 
> 
> 
> The client receives a 404 response, but cowboy crashes:
> 
> =ERROR REPORT==== 8-Sep-2013::22:22:03 ===
> Error in process <0.131.0> with exit value: {function_clause,[{cowboy_req,reply,[200,[],<<31 bytes>>,{http_req,#Port<0.1208>,ranch_tcp,keepalive,<0.131.0>,<<3 bytes>>,'HTTP/1.1',{{192,168,1,187},51017},<<12 bytes>>,undefined,80,<<24 bytes>>,undefined,<<0 bytes>>,undefined,[{channel_num,3}],[{<<10 bytes>>,<<11 bytes>>},{<<4 bytes>>,<<12 bytes>>},{<<6 bytes>>,<<3 bytes>>}],[{<<17 bytes>>,undefined},{<<13 bytes>>,undefined},{<<19 bytes>>,undefined},{<<8 bytes>>,undefined},{<<6 bytes>>,[... 
> 
> 
> 
> The issue is that the REST wrapper wants to do the cowboy_req:reply(), and when we do the call we cause the wrapper's call to fail.
> 
> Dan.
> 
> 
> 
> On Tue, Oct 29, 2013 at 4:01 PM, Ivan uemlianin <ivan at llaisdy.com> wrote:
>> Sorry for terse but I only have a phone. Why can't you return a 404 here?  Using something like cowboy:reply(404, ...
>> 
>> Ivan
>> 
>> --
>> festina lente
>> 
>> 
>> On 29 Oct 2013, at 21:25, Daniel Goertzen <daniel.goertzen at gmail.com> wrote:
>> 
>>> My situation is that I have a rest handler that may fail due to invalid url segments.  Example situation:
>>> 
>>> 
>>> init(_Transport, _Req, _Opts) ->
>>>         {upgrade, protocol, cowboy_rest}.
>>> 
>>> content_types_provided(Req, State) ->
>>>     {[{<<"application/json">>, get_json}], Req, State}.
>>> 
>>> get_json(Req0, State) ->
>>>     {Params, Req1} = lists:mapfoldl(fun cowboy_req:binding/2, Req0, [param1, param2, param3, ....]),
>>> 
>>>     case catch other_module:request(Params) of
>>>         {'EXIT', {badarg, _}} ->
>>>             hmmm, Params were bad and I would like to return a 404 code now.
>>>         Result ->
>>>             {jiffy:encode(Result), Req1, State}
>>>     end.
>>> 
>>> 
>>> 
>>> So I would like to return a 404 code when my underlying request function fails, but it appears my choices are:
>>> 
>>> - return a 200 (ok) response with data.
>>> - crash and cause a 500 (Internal Server Error) response to be returned.  Not exactly the sentiment I want.
>>> 
>>> 
>>> Is there some other way to cause a 404 response?
>>> 
>>> I realize I could add path constraint functions, but I will be replicating logic from my underlying request function.  Furthermore, the constraint functions consider parameters in isolation, so that won't work if the validity of parameters is coupled.
>>> 
>>> Thanks,
>>> Dan.
>>> _______________________________________________
>>> Extend mailing list
>>> Extend at lists.ninenines.eu
>>> http://lists.ninenines.eu:81/listinfo/extend
> 
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