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Re: ldp-ISSUE-91 (rel='type' Link-based interaction): The LDP (REST) interactions must be driven by the rel='type' Link header [Linked Data Platform Spec]

From: Alexandre Bertails <bertails@w3.org>
Date: Sat, 23 Nov 2013 11:51:25 -0500
Message-ID: <5290DD0D.4050503@w3.org>
To: "Linked Data Platform (LDP) Working Group" <public-ldp-wg@w3.org>
Actually, the more I think about it, the more I'm puzzled with what it
means being an LDPC.

Sometimes, the LDPC is the RDF resource that has the type
ldp:Container (5.2.7). It is also the subject of the ldp:membershipXXX
triples.

But I can also GET its representation (5.3.X). And I can POST to it
(5.4.X).

This tension is well illustrated with Example 5 [2] as you're expected
to interact (GET, POST, etc.) with <http://example.org/netWorth/nw1/>
but not with <http://example.org/netWorth/nw1/assetContainer/>.

Looks like the confusion was introduced with
ldp:containerResource. And that being of type ldp:Container does not
entail the LDP interactions.

Are LDPC and ldp:Container two different beasts?

Alexandre.

[2] 
https://dvcs.w3.org/hg/ldpwg/raw-file/default/ldp.html#ldpc-ex-membership-full


On 11/22/2013 05:28 PM, Linked Data Platform (LDP) Working Group Issue 
Tracker wrote:
> ldp-ISSUE-91 (rel='type' Link-based interaction): The LDP (REST) interactions must be driven by the rel='type' Link header [Linked Data Platform Spec]
>
> http://www.w3.org/2012/ldp/track/issues/91
>
> Raised by: Alexandre Bertails
> On product: Linked Data Platform Spec
>
> We have already agreed that LDP interactions are not strictly hypermedia driven, as we agreed not to define a new media-type for LDP. Instead we have a Link header for Resource [1].
>
> The problem is that 4.2.10 [1] does not really advertise the LDP interaction, just the "LDP support" for the resource, and the interaction is currently derived from a { <> a ldp:Container } triple (or its absence). That means than I cannot create a simple LDPR with that triple _without_ the related interaction model. This is wrong.
>
> My proposal is to say that the interaction model is directly (and solely) derived from the "type" Link header, having one for the LDPR and one for the LDPC. This is aligned with the previous proposal of not defining a new media type but to extend the existing RDF ones with the rel='type' Link header.
>
> For an LDPR (and ideally for Binary if it also were an LDPR):
> Link: <http://www.w3.org/ns/ldp#Resource>; rel="type"
>
> For an LDPC:
> Link: <http://www.w3.org/ns/ldp#Container>; rel="type"
>
> Now, I can copy the content of an LDPC (eg. for backup purposes) into a new LDPR, without inheriting the LDPC interactions.
>
> Also, creating an LDPC is now easy to define (and implement): you POST a document *with* the corresponding Link header (otherwise, it's an LDPR, or a Binary).
>
> Alexandre.
>
> [1] https://dvcs.w3.org/hg/ldpwg/raw-file/default/ldp.html#ldpr-4_2_10
>
>
>
>
Received on Saturday, 23 November 2013 16:51:12 UTC

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