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Subject: RE: Fooling around with cocoon davmap
Date: Mon, 3 Nov 2003 01:57:50 +0100
Message-ID: <84F0A43A4248CE45B5C0E20F4C40779C36CC60@naomi.webworks.nl>
Thread-Topic: Fooling around with cocoon davmap
Thread-Index: AcOhiDalDYWCn0BwQpuHCBUtBHQUsQADNBCg
From: "Unico Hommes" <Unico@hippo.nl>
To: <dev@cocoon.apache.org>


Sylvain Wallez wrote:
>=20
> Unico Hommes wrote:
>=20
> >Sylvain Wallez wrote:
> >
> >
> >>Unico Hommes wrote:
> >>
>=20
> <snip/>
>=20
> >>>I just had a look at the code, seems it was already a FIXME on
> Sylvain's list. Can I go ahead and make this change?
> >>>
> >>>
> >>Uh? Where's that list??
> >>
> >>
> >
> >
> >CallFunctionNode.java ln 166/184:
> >// FIXME (SW) : is a flow allowed not to redirect ?
> >
> >;-D
> >
> >
>=20
> Uh (again)? I'm wondering if there's not a misunderstanding here: this
> FIXME is about knowing if a flowscript is allowed to terminate without
> stating what page it to be displayed, i.e. check if one of sendPage(),
> sendPageAndWait() or redirectTo() was called.
>=20
> Sorry, but I don't see how this relates to HEAD, ETags et al... What
was
> the change you proposed to do?
>=20

We were talking about the fact that it seemed impossible to serve a
request without also sending an entity body along with the response.
(Short of suppressing the output in the serializer which is more of hack
than a solution). I thought it was allowed to call a flow function and
then not send a page. But apparently was wrong. Stefano agreed that it
should be legal to call a flow function that does not redirect to a page
in order to cover the full range HTTP better.

Specifically we were discussing the specification of the OPTIONS method
that prescribes that "the response MUST NOT include entity information
other than what can be considered as communication options" which seems
to exclude sending an entity body from being such a legal response.

I traced the above location as the place the code would need to be
changed in order to achieve this. But I could be wrong.

> BTW, can someone explain me what ETags are about (read that in the
http
> RFC a long time ago, but did not really understood at that time).
>=20

I just looked. It seems entity tags are used as cache validators,
similar to Last-Modified header I guess, i.e. they encode the state of a
resource entity so that clients can optimize network calls by sending
along headers like If-Match, If-None-Match, If-Range, that are then be
checked against the current value of the entity tag on the server. If
they match (or not) the method is executed. At least that's what I got
out of it.

-- Unico

> Sylvain
>=20
> --
> Sylvain Wallez                                  Anyware Technologies
> http://www.apache.org/~sylvain           http://www.anyware-tech.com
> { XML, Java, Cocoon, OpenSource }*{ Training, Consulting, Projects }
> Orixo, the opensource XML business alliance  -  http://www.orixo.com
>=20