Re: request for verification: paging in TPF

Hi Markus,

Thanks for taking the time for checking this.

>   The page MUST contain a non-empty subset of data of the corresponding
>   Triple Pattern Fragment
> 
> Why the MUST there? Wouldn't a SHOULD suffice? Think of cases where the
> underlying data changes. What should happen in that case? 404 or empty page?

Indeed, the MUST is wrong.
The purpose of this statement was to avoid that clients unnecessarily follow "next" links.
What I really meant was:

    Any page other than the last page MUST NOT be empty.

Would this make sense?

> This sounds exactly like what hydra:view was designed for. But I would first
> like to ask your for a simple example to ensure that we are on the same page.

I'll continue the example from the gist:

<http://fragments.dbpedia.org/2015/en#dataset> a void:Dataset, hydra:Collection;
    hydra:view <http://fragments.dbpedia.org/2015/en?subject=http%3A%2F%2Fdbpedia.org%2Fresource%2FNikola_Tesla&predicate=&object=&page=2>;
    void:subset <http://fragments.dbpedia.org/2015/en?subject=http%3A%2F%2Fdbpedia.org%2Fresource%2FNikola_Tesla&predicate=&object=>.

Can I already use hydra:view?

> I guess adding an example directly to the spec would be good as well.

Yes; especially the "metadata controls" section, which is now example-based, should:
– first be explained without an example
– then be exemplified together with all features

> Btw. have you considered that "fragment IRI" could be misinterpreted as "IRI fragment"?

Not yet; we should probably talk about "IRI of the fragment".

> Wow, that was fast!

Yeah… I was a bit… too up to speed today… :-)

> Seems to be inline but it's a bit hard to read a multi-page example.

Can I help?
For instance, I could deploy a live instance somewhere.

>> Current issue: hydra:itemsPerPage is gone. How to mitigate this?
> 
> Is it actually needed in this case?

a) Not needed for simple usage, but I want to replicate the human view, which has this.
b) Needed for some of the existing TPF query algorithms that do predictions based on page size.
(Those could also count the number of items per page, but not in all cases.)

Thanks,

Ruben

Received on Thursday, 29 October 2015 23:05:42 UTC