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

Re: URIs in @rel and @property...

From: Ivan Herman <ivan@w3.org>
Date: Mon, 16 Nov 2009 14:46:53 +0100
Message-ID: <4B0157CD.4020906@w3.org>
To: Mark Birbeck <mark.birbeck@webbackplane.com>
CC: Niklas Lindström <lindstream@gmail.com>, Ben Adida <ben@adida.net>, RDFa <public-rdf-in-xhtml-tf@w3.org>
Pfew...:-)

Ivan

P.S. Mark-the-elephant-hunter:-)

Mark Birbeck wrote:
> Hi Ivan/Niklas,
> 
> 2009/11/16 Ivan Herman <ivan@w3.org>:
>> Hi Niklas,
>>
>> Niklas Lindström wrote:
>>>> So is there an elephant?:-)
>>> I haven't followed this discussion to closely, so I want to check if
>>> this the following is considered:
>>>
>>> This usage will "muddle the waters" in cases when the relative URI:s
>>> contain colon, and there is a prefix with the same name as the leading
>>> part before that, right? Concrete (but contrieved) example:
>>>
>>> Given:
>>>     - base URI: <http://en.wikipedia.org/wiki/>
>>>     - prefix Talk: <http://example.org/schema/talk#>
>>>
>>> When:
>>>     @resource="Talk:Linked_Data"
>>>
>>> Then:
>>>     - URI becomes < http://example.org/schema/talk#Linked_Data>,
>>> instead of <http://en.wikipedia.org/wiki/Talk:Linked_Data>, which is
>>> might be expected?
>>>
>> Hm. You may found the elephant:-)
>>
>> Yes, in this case one would indeed get the example.org URI.
>>
>> The question is: is this use case so strong as to nullify the advantages
>> of using CURIE-s in @about? Indeed, wikipedia uses such URI-s with ':'
>> quite a lot but the user can of course put full URI-s into the value of
>> @about...
>>
>> Thanks!
> 
> 
> Whoah...slow down. :)
> 
> "Talk:Linked_Data" is not a relative path!
> 
> Forget prefixes, CURIEs, whatever...even if those things did not
> exist, how would a URI processor know whether "Talk:" is a scheme or
> just part of a relative path?
> 
> RFC 3986 [1] addresses this in the following way:
> 
>   A path segment that contains a colon character (e.g., "this:that")
> cannot be used as the
>   first segment of a relative-path reference, as it would be mistaken
> for a scheme name.
>   Such a segment must be preceded by a dot-segment (e.g.,
> "./this:that") to make a
>   relative-path reference.
> 
> So, if people are using relative paths that contain colons, in the
> wild, then there's a problem, and that problem is completely
> independent of RDFa.
> 
> Regards,
> 
> Mark
> 
> [1] <http://www.ietf.org/rfc/rfc3986.txt>
> 
> --
> 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)

-- 

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 Monday, 16 November 2009 13:47:29 UTC

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