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<H1>[99s-extend] Using cowboy_req:body more than once per request</H1>
<B>Loïc Hoguin</B>
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TITLE="[99s-extend] Using cowboy_req:body more than once per request">essen at ninenines.eu
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<I>Tue Sep 16 00:22:27 CEST 2014</I>
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<PRE>It seems a bit weird to me to read the body and validate it before
validating the request itself.
I would explicitly put these checks in the handler directly. This of
course means that there is no need to read it twice anymore.
On 09/15/2014 11:24 PM, Paulo F. Oliveira wrote:
><i> Hi.
</I>><i>
</I>><i> I recently implemented a checksum header (X-Checksum) that allows
</I>><i> validating the content of a request's body by hash comparison (just to
</I>><i> give you some context). I'm using the onrequest hook to affect all
</I>><i> requests (and be able to reply appropriately for non-conformance to the
</I>><i> hash function result) but can't figure out how to not read the request
</I>><i> body twice, i.e. I read it in the onrequest hook but later on need to
</I>><i> read it again in the route handler, but I can't (from the manual, for
</I>><i> cowboy_req:body: "This function can only be called once. Cowboy will not
</I>><i> cache the result of this call."). At the moment, and because the API
</I>><i> consumers were in a hurry, the solution I found (I understand it might
</I>><i> be an ugly hack), was to read the body, store it in the Req's meta
</I>><i> (property body, for example) and then access that property later on,
</I>><i> instead of using cowboy_req:body. I'm not quite happy with this solution
</I>><i> and was wondering if there is anything more elegant that I can implement.
</I>><i>
</I>><i> Thanks.
</I>><i>
</I>><i> Cheers.
</I>><i>
</I>><i> - Paulo F. Oliveira
</I>><i>
</I>><i>
</I>><i> _______________________________________________
</I>><i> Extend mailing list
</I>><i> <A HREF="https://lists.ninenines.eu/listinfo/extend">Extend at lists.ninenines.eu</A>
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--
Loïc Hoguin
<A HREF="http://ninenines.eu">http://ninenines.eu</A>
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