W3C home > Mailing lists > Public > public-ldp-wg@w3.org > January 2013

Re: ISSUE-37: the Graph and Links model

From: Roger Menday <roger.menday@uk.fujitsu.com>
Date: Mon, 14 Jan 2013 08:15:25 +0000
CC: "public-ldp-wg@w3.org Group" <public-ldp-wg@w3.org>
Message-ID: <75995B27-D408-4D03-BF5C-4849CBD244BD@uk.fujitsu.com>
To: Andy Seaborne <andy.seaborne@epimorphics.com>

hi Andy, 

>> 
>> Although I wouldn't call it the "general case". I would call it the
>> "unconstrained case".
>> 
>> Anyway, I think that the case of arbitrary graph evolution must also
>> be server directed. After-all, it is the server that needs to approve
>> that it able to manage an arbitrarily evolving graph (not least
>> because a LDP server-side might not be built on top of a triple
>> store).
> 
> Why does "on top a triple store" matter?

Put another way: if a LDP service happens to be built on top of a table model (which can't easy accommodate arbitrary data), then it shouldn't have to accept arbitrary inserts to be able to call itself LDP compliant, particularly when the application needs constrained interaction.  

> In fact, it seems at odds with 
> containers, server or client.

can you explain what exactly is at odds with containers ? 

> 
> If the client can PUT to a new resource, it can create new LDP-R.
> 

Well ok, but what if the client *can't* PUT ? (because the server rejects the operation). The result is that they cannot create a LDP-R, I suppose. 

Or are you saying that they always can make this create successfully ? 

However, don't you think it is more efficient and useful when the server directs that interaction ? 


What I am saying is that if the application requires arbitrary creation, then reflect this in the resources (with very liberal affordances in that case). 

Roger

> 	Andy
> 
>> 
>> Roger
>> 
>>> All the best, Ashok
>>> 
>>> On 1/13/2013 1:08 PM, Roger Menday wrote:
>>>> hi Ashok,
>>>> 
>>>>> Can a client create collections from this root resource?
>>>> Yes, when directed in the application.
>>>> 
>>>> I would like to ask a question back to you. Are you mainly
>>>> thinking of 'freestyle' applications (where a client can evolve
>>>> the graph however they please), or more constrained applications
>>>> ?
>>>> 
>>>> I don't ignore the freestyle kind, but, most of my scenario's are
>>>> the more  constrained variety.
>>>> 
>>>> For example, in the Bug tracker scenario, if a Bug is to have an
>>>> associated collection of Comment resources, this is something
>>>> that the server sets-up for the client to follow and interact
>>>> with, i.e. when a Bug resource is created, the server also
>>>> provides the means for a client to discover that Comments can be
>>>> created.
>>>> 
>>>> regards, Roger
>>>> 
>>>>> All the best, Ashok
>>>> 
>>>>> On 1/12/2013 10:22 AM, Roger Menday wrote:
>>>>>> hello there
>>>>>> 
>>>>>>>> 4. "Does each LDP model have/need a service document? If
>>>>>>>> yes, perhaps collections could be created by PUT on the
>>>>>>>> service document?"
>>>>>>>> 
>>>>>>>> I don't see a need for service documents.
>>>>>>> apart from the terminology "service document", i am
>>>>>>> wondering how you are envisioning interactions with the
>>>>>>> server for collection management, when you don't have a
>>>>>>> resource that allows you to provide interaction affordances
>>>>>>> for things such as, for example, the creation of
>>>>>>> collections?
>>>>>> the server provides a well-known 'root' resource from which
>>>>>> the interaction affordances, existing resources, etc. can be
>>>>>> discovered. just like on the HTML web.
>>>>>> 
>>>>>> Roger
>>>>>> 
>>>>>>> thanks and cheers,
>>>>>>> 
>>>>>>> dret.
>>>>>>> 
>>> 
>> 
> 



Received on Monday, 14 January 2013 08:16:40 UTC

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