Hi Nicolas,
On 01/02/12 06:38, Nicolas Nobelis wrote:
Hello,
First of all, sorry if this question has already been asked. I did a
search and some old result pop up
(http://tech.groups.yahoo.com/group/jena-dev/message/1480), but this
is still not clear for me.
1/ First question : I would like to create an individual with a space
is its name : "room_Hamburg_Am Hauptbahnhof 3_07.OG_NIC7"
To do so, I encode the name with URIRef and I get something like :
"room_Hamburg_Am%20Hauptbahnhof%203_07.OG_NIC7"
Yes - you have to do this.
Strictly, space is allowed in an "RDF URI Reference" but none of the
syntaxes can write it down safely because they use "URIs". i.e. you
can't use spaces in practice.
RDF 1.1 will remove phrase "RDF URI Reference" and say "IRI" and there
you can't use raw space.
RDF-2004 tied to align with RFC 3987, but published before the RFC,
which changed it's mind on spaces.
If this local name legal ?
It is a legal part of a URI.
A "local name" is a syntactic device for writing down URIs.
If a URI can't be written as prefixed name (i.e Turtle) it will be
written in long <...> form.
RDF.XML is a bit different - properties can only be written as qnames so
it must be possible to have namespace+local name.
Now, if I create the individual :
> String namespace = "http://example.com/location.owl#";
> OntModel m_model =
ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM);
> Individual i = m_model.createIndividual(namespace +
"room_Hamburg_Am%20Hauptbahnhof%203_07.OG_NIC7", aClass)
So you are passing the full URI to Jena - your code did the + beforfe
the call to createIndividual.
>
and I pring
the local name : println(i.getLocalName())
I then get : _07.OG_NIC7
Internl, Jen astore the URI. If you ask for the local name, it
calculates the longest part that is still legal for XML.
In this case, "_07.OG_NIC7" is the best it can do. The
Obviously there is something wrong here, because I expect
"room_Hamburg_Am%20Hauptbahnhof%203_07.OG_NIC7", right ?
Afraid not - "_07.OG_NIC7" is the best the system can do.
Not local names don't really matter - they are just surface syntax.
2/ Other question :
I there a magic method in the Jena API that, given a String,
transform it to a proper localName ? (sanitize it)
Yes - you called it :-) I'm afraid the rules of local names aren't
always what you want as they cater for RDF/XML.
RDF 1.1 is going to change this for the better.
1/ The local part of a Turtle prefix name will allow %20
2/ Turtle prefix names will be able to start with a number (XML qnames
can't).
3/ Other interesting chars can be escaped into a local name. e.g. ":" as \:
This is not implemented in Jena yet - the details have not been
finalized by the RDF working group.
I thought that URIRef.encode was doing this job, but it doesn't
correct some illegal local names, such as the ones beginning with
numbers (an entity with URI "http://example.com/location.owl#123"; is
illegal according the specs
(http://www.w3.org/TR/xml-names/#NT-NCName))
Yes - XML rules are pretty restrictive.
I tried also IRIFactory, but it seems to only report errors, no
correct them by itself.
Thanks a lot by advance for any answer,
Best regards
N. Nobelis
Summary: put this into the data:
http://example.com/location.owl#room_Hamburg_Am%20Hauptbahnhof%203_07.OG_NIC7
and don't worry too much about local names.
Hope that helps,
Andy
