1XML::Atom::OWL(3) User Contributed Perl Documentation XML::Atom::OWL(3)
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6 XML::Atom::OWL - parse an Atom file into RDF
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9 use XML::Atom::OWL;
10 $parser = XML::Atom::OWL->new($xml, $baseuri);
12 $graph = $parser->graph;
13
15 This has a pretty similar interface to RDF::RDFa::Parser.
16 Constructor
18 "new($xml, $baseuri, \%options, $storage)"
19 This method creates a new XML::Atom::OWL object and returns it.
20 The $xml variable may contain an XML (Atom) string, or an
22 XML::LibXML::Document object. If a string, the document is parsed
23 using XML::LibXML, which will throw an exception if it is not well-
24 formed. XML::Atom::OWL does not catch the exception.
25 The base URI is used to resolve relative URIs found in the
27 document.
28 Currently only one option is defined, 'no_fetch_content_src', a
30 boolean indicating whether <content src> URLs should be
31 automatically fetched and added to the model as if inline content
32 had been provided. They are fetched by default, but it's pretty
33 rare for feeds to include this attribute.
34 $storage is an RDF::Trine::Storage object. If undef, then a new
36 temporary store is created.
37 Public Methods
39 "uri"
40 Returns the base URI of the document being parsed. This will
41 usually be the same as the base URI provided to the constructor.
42 Optionally it may be passed a parameter - an absolute or relative
44 URI - in which case it returns the same URI which it was passed as
45 a parameter, but as an absolute URI, resolved relative to the
46 document's base URI.
47 This seems like two unrelated functions, but if you consider the
49 consequence of passing a relative URI consisting of a zero-length
50 string, it in fact makes sense.
51 "dom"
53 Returns the parsed XML::LibXML::Document.
54 "graph"
56 This method will return an RDF::Trine::Model object with all
57 statements of the full graph.
58 This method automatically calls "consume".
60 "root_identifier"
62 Returns the blank node or URI for the root element of the Atom
63 document as an RDF::Trine::Node
64 Calls "consume" automatically.
66 "set_callbacks(\%callbacks)"
68 Set callback functions for the parser to call on certain events.
69 These are only necessary if you want to do something especially
70 unusual.
71 $p->set_callbacks({
73 'pretriple_resource' => sub { ... } ,
74 'pretriple_literal' => sub { ... } ,
75 'ontriple' => undef ,
76 });
77 For details of the callback functions, see the section CALLBACKS.
79 "set_callbacks" must be used before "consume". "set_callbacks"
80 itself returns a reference to the parser object itself.
81 "consume"
83 The document is parsed. Triples extracted from the document are
84 passed to the callbacks as each one is found; triples are made
85 available in the model returned by the "graph" method.
86 This function returns the parser object itself, making it easy to
88 abbreviate several of XML::Atom::OWL's functions:
89 my $iterator = XML::Atom::OWL->new(undef, $uri)
91 ->consume->graph->as_stream;
92 You probably only need to call this explicitly if you're using
94 callbacks.
95
97 Several callback functions are provided. These may be set using the
98 "set_callbacks" function, which taskes a hashref of keys pointing to
99 coderefs. The keys are named for the event to fire the callback on.
100 pretriple_resource
102 This is called when a triple has been found, but before preparing the
103 triple for adding to the model. It is only called for triples with a
104 non-literal object value.
105 The parameters passed to the callback function are:
107 • A reference to the "XML::Atom::OWL" object
109 • A reference to the "XML::LibXML::Element" being parsed
111 • Subject URI or bnode (string)
113 • Predicate URI (string)
115 • Object URI or bnode (string)
117 • Graph URI or bnode (string or undef)
119 The callback should return 1 to tell the parser to skip this triple
121 (not add it to the graph); return 0 otherwise.
122 pretriple_literal
124 This is the equivalent of pretriple_resource, but is only called for
125 triples with a literal object value.
126 The parameters passed to the callback function are:
128 • A reference to the "XML::Atom::OWL" object
130 • A reference to the "XML::LibXML::Element" being parsed
132 • Subject URI or bnode (string)
134 • Predicate URI (string)
136 • Object literal (string)
138 • Datatype URI (string or undef)
140 • Language (string or undef)
142 • Graph URI or bnode (string or undef)
144 Beware: sometimes both a datatype and a language will be passed. This
146 goes beyond the normal RDF data model.)
147 The callback should return 1 to tell the parser to skip this triple
149 (not add it to the graph); return 0 otherwise.
150 ontriple
152 This is called once a triple is ready to be added to the graph. (After
153 the pretriple callbacks.) The parameters passed to the callback
154 function are:
155 • A reference to the "XML::Atom::OWL" object
157 • A reference to the "XML::LibXML::Element" being parsed
159 • An RDF::Trine::Statement object.
161 The callback should return 1 to tell the parser to skip this triple
163 (not add it to the graph); return 0 otherwise. The callback may modify
164 the RDF::Trine::Statement object.
165
167 Please report any bugs to <http://rt.cpan.org/>.
168
170 RDF::Trine, XML::Atom::FromOWL.
171 <http://www.perlrdf.org/>.
173
175 Toby Inkster <tobyink@cpan.org>.
176
178 Copyright 2010-2011 Toby Inkster
179 This library is free software; you can redistribute it and/or modify it
181 under the same terms as Perl itself.
182
184 THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
185 WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
186 MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
187perl v5.34.0 2022-01-21 XML::Atom::OWL(3)