NAME

RDF::aREF::Query - aREF query expression

SYNOPSIS

    my $rdf = {
        'http://example.org/book' => {
            dct_creator => [
                'http://example.org/alice', 
                'http://example.org/bob'
            ]
        },
        'http://example.org/alice' => {
            foaf_name => "Alice"
        },
        'http://example.org/bob' => {
            foaf_name => "Bob"
        }
    };

    my $getnames = RDF::aREF::Query->new( 
        query => 'dct_creator.foaf_name' 
    );
    my @names = $getnames->apply( $rdf, 'http://example.org/boo' );
    $getnames->query; # 'dct_creator.foaf_name'

    use RDF::aREF qw(aref_query_map);
    my $record = aref_query_map( $rdf, $publication, {
        'dct_creator@' => 'creator',
        'dct_creator.foaf_name' => 'creator',
    });

DESCRIPTION

Implements aREF query, a query language to access strings and nodes from agiven RDF graph.

See also functions aref_query and aref_query_map in RDF::aREF for convenient application.

CONFIGURATION

The constructor expects the following options:

query

aREF query expression

decoder

Instance of RDF::aREF::Decoder to map qNames to URIs. A new instance is created unless given.

ns

Optional namespace map (RDF::NS), passed to the constructor of RDF::aREF::Decoder if no decoder is given.

METHODS

apply( $graph [, $origin ] )

Perform the query on a given RDF graph. The graph can be given as aREF structure (subject map or predicate map) or as instance of RDF::Trine::Model. An origin subject node must be provided unless the RDF graph is provided as predicate map.

query

Returns the aREF query expression

SEE ALSO

Use SPARQL for more complex queries, e.g. with RDF::Trine::Store::SPARQL.