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

From: Mark Birbeck <mark.birbeck@webbackplane.com>
Date: Mon, 16 Nov 2009 13:42:38 +0000
Message-ID: <640dd5060911160542w602c8e10kcae86305b41c7af9@mail.gmail.com>
To: Ivan Herman <ivan@w3.org>
Cc: Niklas Lindström <lindstream@gmail.com>, Ben Adida <ben@adida.net>, RDFa <public-rdf-in-xhtml-tf@w3.org>
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.



[1] <http://www.ietf.org/rfc/rfc3986.txt>

Mark Birbeck, webBackplane



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Received on Monday, 16 November 2009 13:43:22 UTC

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