- From: Niklas Lindström <lindstream@gmail.com>
- Date: Tue, 17 Nov 2009 13:34:41 +0100
- To: Ivan Herman <ivan@w3.org>
- Cc: Mark Birbeck <mark.birbeck@webbackplane.com>, Ben Adida <ben@adida.net>, RDFa <public-rdf-in-xhtml-tf@w3.org>
Another point though. Isn't there a problem if prefixes are declared for existing protocols? When prefixes are declared for e.g.: xmlns:http="http://www.w3.org/2006/http#" xmlns:tag="http://example.org/tagging#" With the proposed rules ("unsafe CURIE or URI"), wouldn't these: about="http://example.org/me" resource="tag:example.org,2009:item:1" be resolved against those prefixes (instead of as-is)? Best regards, Niklas 2009/11/16 Niklas Lindström <lindstream@gmail.com>: > Ah, but indeed! Good elephant-hunting Mark! ;) It's quite comforting > that RFC 3986 is so precise about these things. > > (I should have known that -- I now recall reading that very same rule > a couple of months ago when investigating the legality of non-escaped > colons in URI:s. Only remembered half of it apparently.) > > Best regards, > Niklas > > > 2009/11/16 Ivan Herman <ivan@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 Tuesday, 17 November 2009 12:35:35 UTC