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 <http://gbv.github.io/aREF/aREF.html#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 <http://gbv.github.io/aREF/aREF.html#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
       <http://gbv.github.io/aREF/aREF.html#predicate-maps>.

query

       Returns the aREF query expression

SEE ALSO

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