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Subject: Re: _show without docid returns 500 instead of 404
From: Jan Lehnardt <jan@apache.org>
In-Reply-To: <1259687083.7371.82.camel@zelda.buyways.nl>
Date: Sat, 12 Dec 2009 09:51:58 -0800
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To: user@couchdb.apache.org

Hi,

great thread. Can you open a JIRA ticket so we don't lose track
of this?

https://issues.apache.org/jira/browse/COUCHDB

Cheers
Jan
--

On 1 Dec 2009, at 09:04, Markus Jelsma - Buyways B.V. wrote:

> Hello Chris,
> 
> 
> I'm glad you agree on my assumption that either the book or code is
> wrong and i'm glad something can be done about it.
> 
> Creating a custom 404 respone inside the show function seems
> inappropriate to me. Since show functions are without side-effects they
> cannot rely on other components in rendering a proper response so
> rendering a custom reusable error response is out of the question. And
> besides, a 404 Not Found is - in my opinion - exactly what we need and
> allows/forces for the caller to handle it properly.
> 
> In short, i concur. I would vote for the 404 reply and thus follow the
> instructions in the book.
> 
> 
> Regards,
> M.
> 
> 
> 
> On Tue, 2009-12-01 at 08:44 -0800, Chris Anderson wrote:
> 
> 
>> I think in this case the book is wrong (or maybe it is right and the
>> code is wrong). In the case of a missing doc the code currently forces
>> you to raise the 404 error from your show function.
>> 
>> I think this was done so that you have the option to render your own
>> 404 error message, instead of being stuck with CouchDB's JSON message.
>> 
>> The arguments for the CouchDB handling 404 for you:
>> 
>> It's simpler to program because CouchDB handles some major error
>> handling for you (and properly)
>> It's more efficient b/c your JS function is not called in the case of
>> a missing docid.
>> 
>> The arguments for the current system (handle your own errors) pretty
>> much boil down to some increased flexibility. The flexibility of 404
>> messages might be better handled outside of show functions anyway.
>> 
>> I am leaning toward the description the book gives (which would mean a
>> code change). If you convince me it should be changed, I'll change it.
>> Is anyone relying on the ability of show functions to render their own
>> 404s?
>> 
>> The change would be simple, just remove a catch clause on
>> couch_httpd_show.erl line 81.
>> 
>> Chris
>>