RDF::Query::ServiceDescription - Class for describing federated query data sources.
This document describes RDF::Query::ServiceDescription version 2.910.
new ( $service_uri, %data )
new_from_uri ( $url )
Creates a new service description object using the DARQ-style service description data located at $url.
$url
new_with_model ( $model )
Creates a new service description object using the DARQ-style service description data loaded in the supplied $model object.
$model
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 $capability->{pred} # RDF::Trine::Node::Resource
patterns
Returns an ARRAY reference of RDF::Query::Algebra::BasicGraphPattern objects representing common patterns used by the endpoint.
computed_statement_generator
Returns a closure appropriate for passing to RDF::Query->add_computed_statement_generator to generate statement iterators for the remote service.
RDF::Query->add_computed_statement_generator
This closure takes ($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 [, $context ].
($query, $bridge, \%bound, $subj, $pred, $obj [, $context ] )
undef
RDF::Trine::Iterator::Graph
$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.
Gregory Todd Williams <gwilliams@cpan.org>
To install RDF::Query, copy and paste the appropriate command in to your terminal.
cpanm
cpanm RDF::Query
CPAN shell
perl -MCPAN -e shell install RDF::Query
For more information on module installation, please visit the detailed CPAN module installation guide.