On 07/09/13 00:30, Saud Al-Jaloud wrote:
Hi,
Is there a way with Jena api to pass a SPARQL query that can return the regex
pattern?
For example:
A query like: "PREFIX dc: <http://purl.org/dc/elements/1.1/>
SELECT ?title
WHERE { ?x dc:title ?title
FILTER regex(?title, "^SPARQL")
}"
Should return "^SPARQL". if there are more than one regex, it should return all
regex patterns.
I'm already using my version of regex search to extract the pattern, though it
still misses some patterns. I'd think using Jena is more certain in returning
the exact pattern.
The finest I could get to is to return the query pattern using
Query.getQueryPattern(); not any further.
Thanks,
Saud.
Query.getQueryPattern() returns an Element. You can walk that using a
ElementVisitor.
As you're working with the internals of the system, you'll probably want
to look at the source code. If you look at the classhierarchy (in
Eclipse for example) of ElementVisitor, you'll see some examples.
You may find work with the algebra easier.
http://jena.apache.org/documentation/query/algebra.html
and the OpVisitor, of which there are lots of examples in the code.
Andy
