RDF::Redland::Node - Redland RDF Node (RDF Resource, Property, Literal) Class
use RDF::Redland;
my $node1=new RDF::Redland::Node("Hello, World!");
my $node2=new RDF::Redland::Node($uri); # $uri is an RDF::Redland::URI
my $node3=$node2->clone;
my $node4=new RDF::Redland::URINode("http://example.com/";);
my $node5=new RDF::Redland::LiteralNode("Hello, World!");
my $node6=new RDF::Redland::XMLLiteral("<tag>content</tag>");
my $node7=new RDF::Redland::BlankNode("genid1");
# alternate more verbose ways:
my $node4=RDF::Redland::Node->new_from_uri("http://example.com/";);
my $node5=RDF::Redland::Node->new_literal("Hello, World!");
my $node6=RDF::Redland::Node->new_xml_literal("<tag>content</tag>");
my $node7=RDF::Redland::Node->new_from_blank_identifier("genid1");
...
print $node4->uri->as_string,"\n"; # Using RDF::Redland::URI::as_string
print $node5->literal_value_as_latin1,"\n";
This class represents RDF URIs, literals and blank nodes in the RDF graph.
- new [STRING | URI | NODE]
-
Create a new URI node, literal node or copy an existing node.
If a literal STRING is given, make a plain literal node. If a
the argument is of type URI (perl URI or RDF::Redland::URI),
make a resource node.
Otherwise if the argument is an RDF::Redland::Node NODE, copy it.
- new_from_uri URI
-
Create a new URI node. URI can be either a RDF::Redland::URI
object, a perl URI class or a literal string.
An alternative is:
new RDF::Redland::URINode("http://example.org/";);
- new_literal STRING [DATATYPE [XML_LANGUAGE]]
-
Create a new literal node for a literal value STRING.
Optional datatype URI DATATYPE (RDF::Redland::URI, perl URI or string)
and language (xml:lang attribute) XML_LANGUAGE may also be given.
An alternative is:
new RDF::Redland::LiteralNode("Hello, World!");
new RDF::Redland::LiteralNode("Bonjour monde!", undef, "fr");
- new_xml_literal STRING
-
Create a new XML datatyped literal node for the XML in STRING.
An alternative is:
new RDF::Redland::XMLLiteral("<tag>content</tag>");
- new_from_blank_identifier IDENTIFIER
-
Create a new blank node with blank node identifier IDENTIFIER.
An alternative is:
new RDF::Redland::BlankNode("id");
- clone
-
Copy a RDF::Redland::Node.
- uri
-
Get the current URI of the node as an RDF::Redland::URI object.
- blank_identifier
-
Get the current blank identifier of the node
- type
-
Get the node type. It is recommended to use the is_resource, is_literal
or is_blank methods in preference to this (both simpler and quicker).
The current list of types that are supported are:
$RDF::Redland::Node::Type_Resource
$RDF::Redland::Node::Type_Literal
$RDF::Redland::Node::Type_Blank
Example:
if ($node->type == $RDF::Redland::Node::Type_Resource) {
print "Node is a resource with URI ", $node->uri->as_string, "\n";
} else {
...
}
- is_resource
-
Return true if node is a resource (with a URI)
- is_literal
-
Return true if node is a literal
- is_blank
-
Return true if node is a blank nodeID
- literal_value
-
Get the node literal value string as UTF-8 (when the node is of type
$RDF::Redland::Node::Type_Literal)
- literal_value_as_latin1
-
Get the node literal value string converted from UTF-8 to ISO Latin-1
(when the node is of type $RDF::Redland::Node::Type_Literal)
- literal_value_language
-
Get the node literal XML language (when the node is of type
$RDF::Redland::Node::Type_Literal) or undef if not present.
- literal_value_is_wf_xml
-
Return non 0 if the literal string is well formed XML (when the node
is of type $RDF::Redland::Node::Type_Literal).
- literal_datatype
-
Return the RDF::Redland::URI of the literal datatype or undef if it
is not a datatype.
- as_string
-
Return the RDF::Redland::Node formatted as a string (UTF-8 encoded).
- equals NODE
-
Return non zero if this node is equal to NODE
- new_from_literal STRING XML_LANGUAGE IS_WF
-
Create a new RDF::Redland::Node object for a literal value STRING with XML
language (xml:lang attribute) XML_LANGUAGE
and if content is well formed XML, when IS_WF is non
0. XML_LANGUAGE is optional can can be set to undef.
This method remains but using new_literal is preferred.
Instead, for plain literals use:
$node=new RDF::Redland::Node("blah")
- new_from_typed_literal STRING [DATATYPE [XML_LANGUAGE]]
-
Renamed to new_literal with same arguments.
- new_from_uri_string URI_STRING
-
Create a new RDF::Redland::Node object for a resource with URI URI_STRING.
It is equivalent to use the shorter:
$a=new RDF::Redland::Node->new_from_uri($uri_string)
- new_from_node NODE
-
Create a new RDF::Redland::Node object from existing
RDF::Redland::Node NODE (copy constructor).
It is equivalent to use:
$new_node=$old_node->clone
the RDF::Redland::Statement manpage
Dave Beckett - http://www.dajobe.org/
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