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Re: PROPOSAL for ISSUE-66, a way to detect the ldp:Container has updated during pagination

From: Steve Speicher <sspeiche@gmail.com>
Date: Wed, 19 Jun 2013 13:37:54 -0400
Message-ID: <CAOUJ7JpoNw4hCDgsTWcxQV69tXuu1aYTkscaaKb+bs+G5KiS9Q@mail.gmail.com>
To: "Wilde, Erik" <Erik.Wilde@emc.com>
Cc: "public-ldp-wg@w3.org" <public-ldp-wg@w3.org>

On Wed, Jun 19, 2013 at 11:57 AM, Wilde, Erik <Erik.Wilde@emc.com> wrote:

> hello all.
> On 2013-06-19 1:33 , "Steve Speicher" <sspeiche@gmail.com> wrote:
> >Discussion yesterday on this issue led an action for me to propose a way
> >for a client to detect if the LDPC has changed while a client is flipping
> >through the pages.
> >The proposed solution is for a LDP Server to include in each page a
> >non-member-property that indicates when the LDPC was last changed.  The
> >typical piece of data would be the entity tag of the LDPC.
> >PROPOSAL: Close ISSUE-66, saying to help clients detect when the LDPC
> >they are paging has changed, servers MAY include <ldpc-uri, ldp:etag,
> >etag>.
> this looks like an unfortunate way of designing the protocol. ETags are a
> part of the web's uniform interface in HTTP, and should be exposed in the
> way defined by that interface: in the ETag HTTP header. if you hide that
> information somewhere else, standard HTTP interactions can not take
> advantage of it, and the main reason why it is exposed in the interface is
> that it can be used in HTTP interactions. the golden rule of REST on the
> web: if you are exposing interaction semantics, and the uniform interface
> has a way of exposing them, then expose them through the uniform
> interface. this way, everybody (*including intermediaries*, who have no
> idea who's talking to whom) can use it.

I'm not sure where you get that from the issue and what I propose.  I think
there is some misunderstanding of the problem, did you review the issue
background?  I want to include information about the resource being paged
within the page resource (which has its own URL and ETag).  The issue is
about, how do I know if the ldp:pageOf resource (LDPC or LDPR) has changed
since a client starting flipping through the pages.  The answer we have
today is to do a HTTP HEAD on the ldp:pageOf resource to get ETag or
LastModified to see if anything has changed (regular HTTP stuff).  So the
proposal is an optimization to eliminate these additional requests and I
came up with this simple proposal to just include the ETag, no breaking of
the web.

- Steve Speicher

> cheers,
> dret.
Received on Wednesday, 19 June 2013 17:38:21 UTC

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