#!/bin/env perl

print "==== Example 5 - RDQL query: find author\n" ;
print "==== NB we get matching subgraph - includes our anwser\n" ;

require Joseki ;
require RDF::Core::Model ;

my $kbURL = 'http://jena.hpl.hp.com:2020/books' ;
if ( $#ARGV != -1 )
{
    $kbURL = shift ;
    print "Data source = $kbURL\n" ;
}

my $rdql = 
    'SELECT ?z WHERE '. 
    '(?x dc:title \'Harry Potter and the Philosopher\\\'s Stone\') '.
    '(?x dc:creator ?z) ' .
    'USING book for <http://example.org/book/> dc FOR <http://purl.org/dc/elements/1.1/>' ;

my $m = Joseki->rdql($kbURL, $rdql) ;

printModelStmts($m) ;

sub printModelStmts
{
    my($model) = @_ ;
    my $sIter = $model->getStmts;
    my $stmt = $sIter->getFirst; 
    for(; defined $stmt ; $stmt = $sIter->getNext )
    {
	print "[ ",$stmt->getSubject->getURI,
              ",\n      ",$stmt->getPredicate->getURI,
              ",\n      ",$stmt->getObject->getLabel," ]\n" ;
	
    }
    $sIter->close ;
}