Re: Some thoughts on the RDFa DOM API document

Hi Shane,


On Apr 26, 2010, at 12:49 , Shane McCarron wrote:

[snip]

>  2. I assume that the designation of BlankNodes are constant for the
>     lifetime of a specific document instance.  In otherwords, if I
>     process a page and start using it, depending upon blank node names
>     like '_:123' , that designator will refer to the same node at
>     least until the next time the page is processed.  We should make
>     this explicit if it is true.
> 

If I understand well what you say then I think I disagree. So here is how I understand: if I look at an RDFa page today and run a javascript with the API and I get _:123 as an identifier for a particular bnode, is it true that if I run the same javascript on the same page tomorrow, will I get _:123 as an identifier for the same bnode?

If this is what you ask then my answer is no. There is absolutely no reason for that, _:123 is not a stable and permanent identifier for a node, it is only a temporary identifier at a particular run. It is a perfectly valid implementation of bnodes to use random identifiers, with the only requirement that two different bnodes should have different identifiers. (In fact, RDFLib explicitly runs a random generator to generate a bnode id to avoid giving the false impression that these are stable ID-s.)

Ivan



> -- 
> Shane P. McCarron                          Phone: +1 763 786-8160 x120
> Managing Director                            Fax: +1 763 786-8180
> ApTest Minnesota                            Inet: shane@aptest.com
> 
> 
> 


----
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, 27 April 2010 00:07:48 UTC