Re: Paging with SPARQL CONSTRUCT implementations

John, Erik, Arnaud,

Yes, I can do what you suggest and always provide a nextPage URL until I get zero triples, and then mark that as the last page. Thank you all for clarifying things for me.

Thanks,
Elli



>________________________________
> From: John Arwe <johnarwe@us.ibm.com>
>To: Elli Schwarz <eliezer_schwarz@yahoo.com> 
>Cc: "public-ldp@w3.org" <public-ldp@w3.org> 
>Sent: Friday, June 7, 2013 2:12 PM
>Subject: Re: Paging with SPARQL CONSTRUCT implementations
> 
>
>
>Well, I think there's a couple of things
going on here. 
>
>> ... Do you expect an empty page to be returned?
Or do you also expect this response: 
>> 
>> <http://example.org/netWorth/nw1/assetContainer/?p=55> 
>>    a ldp:Page;
>>    ldp:pageOf <http://example.org/netWorth/nw1/assetContainer/>;
>>    ldp:nextPage rdf:nil.
> 
>I think you have a false dichotomy here.  The
triples you show above is exactly what I meant in my original reply when
I said 
>
>> solution is to always provide a next-page URL
until your construct 
>> returns zero triples (which is still a valid page of content), and 
>> mark it as the last page.   
>
>"marking it as the last page" == adding
the Page triples you showed. 
>It gives every client exactly one way to detect "last
page"; no gratuitous variability (waves to Raul ;-) ).
> 
>
>> What do you expect to happen currently if a user
tries to access the URL <
>> http://example.org/netWorth/nw1/assetContainer/?p=55>
and page 2 is 
>> the last page? 
> 
>As a generic LDP client who knows nothing (zero) about
your server's URL construction rules, I either got that p=55 URL from a
ldp:nextPage triple object (this discussion) or "somewhere else".
 In the latter case, tell me where it came from and I'll you whether
or not I think LDP constrains the answer.  In the former case, I expect
exactly what LDP prescribes, and since it's a different resource there's
very little in the way of MUST/MUSTNOT-constraints coming from LDP.  404/410
is perfectly allowable (not especially reasonable for the case you started
with, but allowable in general). 
>
>If you tell me your client knows anything about the
server's URI construction rules, you're outside of LDP already so you can't
look to LDP for answers. 
>
>Best Regards, John
>
>Voice US 845-435-9470  BluePages 
>Tivoli OSLC Lead - Show me the Scenario 
>
>
>
>