Re: issue-34 example

>> 
>> 
>>>> It seems that we will never see eye-to-eye on this :) I just
>>>> think that what you want to do with LDP, is different from what I
>>>> want to do.
>>>> 
>>>> I want solutions where servers which guide my clients through a
>>>> service. If it is "unfriendly week", the hypermedia directing
>>>> linking with the :friend predicate shouldn't be there. Your
>>>> solution is essentially allowing any data to be added.
>>>> 
>>>> Would you agree ?
>>> 
>>> I agree that I want LDP to support adding arbitrary data.  May not
>>> be the only usage and some implementations may not allow the
>>> opertation (thay can always refuse anything).
>> 
>> Well, the server can always refuse something which would otherwise
>> put the system into an 'illegal' state - but, this isn't the most
>> helpful way of going about things.
> 
> Where is the pre-condition / guidance to the operation?
> 
>> btw: In the 'graph and links model', a resource might either be
>> liberal about which other properties it accepts (or not). This then
>> is a model which covers both arbitrary and constrained data
>> interaction.
>> 
>>>> 
>>>> I hope we can support both in LDP (I think we can).
>>> 
>>> I hope so - I'm having difficulty seeing what state manipulations
>>> you have in mind.  Do you have a concrete example?
>> 
>> Yes ! our LDP example - the Bug tracker.
> 
> "where servers which guide my clients through a service."
> 
> What do you consider as guiding?
> 
> I read "guiding" as, for example, the return indicates what the client 
> can do next (in the same way that sending back a form on a multi step 
> shopping process indicates the next steps).  How does the bug tracker 
> guide the client if it is not just constrains on input (roughly, 
> documentation)?

I think one part of that is when creating the response is not just a clone of the request - or at least, it doesn't have to be. 
Links in the created resources lead the client onwards. 
Also parameters that should be provided to help creation are advertised by the server, and these can vary throughout the life of the resource. 

Roger

> 
> 	Andy
> 
>> It seems that most (almost all) applications have some constraints on
>> how a graph may be evolved by LDP. A concrete, simple example started
>> this email thread; friends and enemies - if I want to add a new arc
>> to a Person, called :friend, it is only allowed to link to another
>> person, etc etc ...
>> 
>> I believe you will see similar constraints in pretty much any "Web
>> API" or "REST API" around on the web.
>> 
>> Roger
>> 
>>> Isn't the only state is the RDF of a LDP-R?  A unique
>>> characteristic here is that an LDP has no hidden/implicit state?
>> 
>> 
>> 
>>> 
>>> Andy
>>> 
>>>> 
>>>> Roger
>>>> 
>>>> 
>>>>> POST, as it's simply additional triples:
>>>>> 
>>>>> <Person/1> :friend <Person/4> .
>>>>> 
>>>>> This follows from "Extending a database through an append
>>>>> operation." (RFC 2616)
>>>>> 
>>>>> (it would be valuable to be explicit that POST to LDP-R is add
>>>>> triples)
>>>>> 
>>>>> Andy
>>>>> 
>>>>> On 18/01/13 00:25, Arnaud Le Hors wrote:
>>>>>> Hi Roger,
>>>>>> 
>>>>>> I have to admit not to understand how your example justifies
>>>>>> adding anything to LDP.
>>>>>> 
>>>>>> The spec as it stands allows you to update resources via PUT.
>>>>>> Why isn't it enough to PUT the new representation with the
>>>>>> added Person? Why does your resource have to be anything
>>>>>> special to the server rather than just another RDF resource
>>>>>> which happens to contain references to a bunch of resources
>>>>>> in a totally standard RDF fashion? -- Arnaud  Le Hors -
>>>>>> Software Standards Architect - IBM Software Group
>>>>>> 
>>>>>> 
>>>>>> Roger Menday <roger.menday@uk.fujitsu.com> wrote on
>>>>>> 01/17/2013 02:31:18 PM:
>>>>>> 
>>>>>>> From: Roger Menday <roger.menday@uk.fujitsu.com> To:
>>>>>>> "public-ldp-wg@w3.org Group" <public-ldp-wg@w3.org>, Date:
>>>>>>> 01/17/2013 02:32 PM Subject: issue-34 example
>>>>>>> 
>>>>>>> 
>>>>>>> Given the following LD.
>>>>>>> 
>>>>>>> <Person/1> :friend <Person/7>, <Person/9> :enemy
>>>>>>> <Person/6>
>>>>>>> 
>>>>>>> Issue-34 says it needs a simple way of linking a new
>>>>>>> friend (<Person/4>), to end up with
>>>>>>> 
>>>>>>> <Person/1> :friend <Person/7>, <Person/9>, <Person/4>
>>>>>>> :enemy <Person/6>
>>>>>>> 
>>>>>>> ?
>>>>>>> 
>>>>>>> So, I believe that aggregation is an essential piece for
>>>>>>> lDP.
>>>>>>> 
>>>>>>> regards, Roger
>>>>> 
>>>> 
>>> 
>> 
> 

Received on Monday, 21 January 2013 11:00:07 UTC