NAME

       RDF::Query::ServiceDescription - Class for describing federated query data sources.

VERSION

       This document describes RDF::Query::ServiceDescription version 2.918.

METHODS

       "new ( $service_uri, %data )"
       "new_from_uri ( $url )"
           Creates  a  new  service  description object using the DARQ-style service description data located at
           $url.

       "new_with_model ( $model )"
           Creates a new service description object using the DARQ-style service description data loaded in  the
           supplied $model object.

       "url"
           Returns the endpoint URL of the service.

       "size"
           Returns the number of triples the service claims to have.

       "label"
           Returns the label of the service.

       "definitive"
           Returns true if the endpoint claims to have definitive information.

       "capabilities"
           Returns an ARRAY reference of capabilities (as HASH references) of the service.  Each capability will
           contain information on size, selectivity, any subject-object filter, and required predicate, with the
           following classes:

             $capability->{object_selectivity} # RDF::Trine::Node::Literal xsd:double
             $capability->{sofilter} # RDF::Query::Expression
             $capability->{size} # RDF::Trine::Node::Literal xsd:integer
             $capability->{pred} # RDF::Trine::Node::Resource

       "patterns"
           Returns  an  ARRAY  reference  of  RDF::Query::Algebra::BasicGraphPattern objects representing common
           patterns used by the endpoint.

       "computed_statement_generator"
           Returns a  closure  appropriate  for  passing  to  "RDF::Query->add_computed_statement_generator"  to
           generate statement iterators for the remote service.

           This  closure  takes "($query, $bridge, \%bound, $subj, $pred, $obj [, $context ] )" as arguments and
           returns  either  "undef"  if  no  statements  can  be   generated   given   the   arguments,   or   a
           "RDF::Trine::Iterator::Graph" iterator containing statements matching "$subj, $pred, $obj [, $context
           ]".

       "answers_triple_pattern ( $triple )"
           Returns  true  if  the  service described by this object can answer queries comprised of the supplied
           triple pattern.

AUTHOR

        Gregory Todd Williams <gwilliams@cpan.org>

perl v5.38.2                                       2024-04-30                RDF::Query::ServiceDescription(3pm)