W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > November 2009

Re: Proposal for 'URIs everywhere'

From: Gregg Kellogg <gregg@kellogg-assoc.com>
Date: Fri, 27 Nov 2009 15:23:27 -0500
To: Mark Birbeck <mark.birbeck@webbackplane.com>
CC: Ivan Herman <ivan@w3.org>, Toby Inkster <tai@g5n.co.uk>, W3C RDFa task force <public-rdf-in-xhtml-tf@w3.org>
Message-ID: <907B23D1-1936-44D3-9A81-046AA9E4E689@kellogg-assoc.com>
+1

[a:b] should generate an error if "" is undefined.

Gregg Kellogg
Sent from my iPhone

On Nov 27, 2009, at 1:00 PM, "Mark Birbeck" <mark.birbeck@webbackplane.com 
 > wrote:

> Wow...great work Ivan and Toby. :)
>
> The algorithm I outlined is actually ever so slightly different to
> what you have described Ivan.
>
> Obviously it's all up for debate, but just so that we can have that
> discussion, I'll clarify what I was proposing.
>
> We've agreed that we're now saying that this is not a CURIE:
>
>  a:b
>
> but this is:
>
> @prefix a: <http://example.com/>
>
> a:b
>
> I.e., if a mapping is defined, then we have a CURIE, if not, we have  
> a URI.
>
> However...
>
> I believe it would be useful to say that the following will *never*
> become a URI:
>
>  [a:b]
>
> My feeling is that in this situation the author is saying that they
> explicitly want to use the CURIE 'a:b' with the mapping 'a'. And if
> the mapping 'a' doesn't exist, then something has gone wrong, and they
> would prefer it to be ignored altogether.
>
> I'm seeing this as a useful 'strict' mode, that automated systems
> might want to use, but hand-coders would almost certainly avoid.
>
> Any thoughts?
>
> Regards
>
> Mark
>
> --
> Mark Birbeck, webBackplane
>
> mark.birbeck@webBackplane.com
>
> http://webBackplane.com/mark-birbeck
>
> webBackplane is a trading name of Backplane Ltd. (company number
> 05972288, registered office: 2nd Floor, 69/85 Tabernacle Street,
> London, EC2A 4RR)
>
>
>
>
> On Fri, Nov 27, 2009 at 5:18 PM, Ivan Herman <ivan@w3.org> wrote:
>> I redid the relevant part of my distiller, too, and it is much  
>> nicer and
>> simpler. It is one single method that has some internal branches, but
>> can still handle @rel/@rev/@about/@resource/@typeof in one place. An
>> this is nice. What it does with 'value':
>>
>> 1. Get the possible safe curie signs out of the way at the start,  
>> ie, if
>> the value is of the form '[...]' then remove the [ and ] signs. Ie,  
>> the
>> safe curie is there for backward compatibility only. (And yes, that
>> means that I do allow unsafe curies for @about and @resource)
>>
>> 2. Get the possible blank node management out of the way, ie return  
>> the
>> right blank node for things like '_:a'. Note that if this is called  
>> for
>> a @rel/@property/@ref, then return None (with possible error message)
>> because you cannot have a blank node for a predicate
>>
>> 3. If it is called on @rel/@rev and the value is a keyword then  
>> return
>> the corresponding URI
>>
>> 4. Try to match the value against a CURIE definition (ie, see if it  
>> is
>> of the form a:b and 'a' is defined as a namespace, oops, local  
>> name). If
>> yes, return the corresponding URI
>>
>> 5. If we get here, this is a real URI (absolute or relative), and  
>> fall
>> back to the usual URI management to get the final URI (there are  
>> python
>> tools to do that with all the quirks of relative uris and the like).
>>
>> I think this is in line with what Mark describes. I have written it  
>> down
>> here to see if it is what Mark had in mind (until we have relevant  
>> test
>> cases...)
>>
>> I plan to test a bit more and put up a test version of the distiller
>> service on line with an extra "1.1" flag to trigger this behaviour.
>> Hopefully on the week end or early next week.
>>
>> Ivan
>>
>>
>> Toby Inkster wrote:
>>> On Wed, 2009-11-25 at 22:06 +0000, Mark Birbeck wrote:
>>>> Anyway, below you'll find a series of minor changes that I feel  
>>>> would
>>>> need to be made to various parts of the syntax document, in order  
>>>> to
>>>> support URIs and CURIEs in all RDFa-related attributes (except @src
>>>> and @href).
>>>
>>> The following describes the behaviour of the unreleased
>>> RDF::RDFa::Parser 0.21 package for Perl. (Latest released version is
>>> 0.20.)
>>>
>>> If the parser is instantiated with the option "full_uris" set to  
>>> true,
>>> then, it uses the following behaviour for these attributes:
>>>
>>> @about/@resource: Safe CURIE, falling back to URIs.
>>> @src/@href: URIs only.
>>> @rel/@rev: Keywords, falling back to safe CURIEs, CURIEs then URIs.
>>> @property/@typeof/@datatype: Safe CURIEs, CURIEs then URIs.
>>>
>>> I think this is more or less the same as your proposal, except that
>>> unsafe CURIEs are disallowed in @about/@resource.
>>>
>>> By default, i.e. when "full_uris" is not true, it uses:
>>>
>>> @about/@resource: Safe CURIE, falling back to URIs.
>>> @src/@href: URIs only.
>>> @rel/@rev: Keywords, falling back to safe CURIEs, then CURIEs.
>>> @property/@typeof/@datatype: Safe CURIEs, falling back to CURIEs.
>>>
>>> And as of 0.21 it's now passing all 107 approved tests in the XHTML 
>>> +RDFa
>>> test suite. (Yay!)
>>>
>>
>> --
>>
>> Ivan Herman, W3C Semantic Web Activity Lead
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> PGP Key: http://www.ivan-herman.net/pgpkey.html
>> FOAF: http://www.ivan-herman.net/foaf.rdf
>>
>
Received on Friday, 27 November 2009 20:24:31 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 17:02:05 UTC