Source code for rdflib.plugins.parsers.pyRdfa.embeddedRDF
# -*- coding: utf-8 -*-
"""
Extracting possible embedded RDF/XML content from the file and parse it separately into the Graph. This is used, for example
by U{SVG 1.2 Tiny<http://www.w3.org/TR/SVGMobile12/>}.
@author: U{Ivan Herman<a href="http://www.w3.org/People/Ivan/">}
@license: This software is available for use under the
U{W3C® SOFTWARE NOTICE AND LICENSE<href="http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231">}
@contact: Ivan Herman, ivan@w3.org
@version: $Id: embeddedRDF.py,v 1.15 2012/11/16 17:51:53 ivan Exp $
"""
# Python 3 foolproof way...
try :
from io import StringIO
except :
from StringIO import StringIO
from .host import HostLanguage, accept_embedded_rdf_xml, accept_embedded_turtle
from .utils import return_XML
import re, sys
[docs]def handle_embeddedRDF(node, graph, state) :
"""
Handles embedded RDF. There are two possibilities:
- the file is one of the XML dialects that allows for an embedded RDF/XML portion. See the L{host.accept_embedded_rdf_xml} for those (a typical example is SVG).
- the file is HTML and there is a turtle portion in the C{<script>} element with type text/turtle.
@param node: a DOM node for the top level element
@param graph: target rdf graph
@type graph: RDFLib's Graph object instance
@param state: the inherited state (namespaces, lang, etc)
@type state: L{state.ExecutionContext}
@return: whether an RDF/XML or turtle content has been detected or not. If TRUE, the RDFa processing should not occur on the node and its descendents.
@rtype: Boolean
"""
#def _get_prefixes_in_turtle() :
# retval = ""
# for key in state.term_or_curie.ns :
# retval += "@prefix %s: <%s> .\n" % (key, state.term_or_curie.ns[key])
# retval += '\n'
# return retval
# This feature is optional!
def _get_literal(Pnode):
"""
Get the full text
@param Pnode: DOM Node
@return: string
"""
rc = ""
for node in Pnode.childNodes:
if node.nodeType in [node.TEXT_NODE, node.CDATA_SECTION_NODE] :
rc = rc + node.data
# Sigh... the HTML5 parser does not recognize the CDATA escapes, ie, it just passes on the <![CDATA[ and ]]> strings:-(
return rc.replace("<![CDATA[","").replace("]]>","")
if state.options.embedded_rdf :
# Embedded turtle, per the latest Turtle draft
if state.options.host_language in accept_embedded_turtle and node.nodeName.lower() == "script" :
if node.hasAttribute("type") and node.getAttribute("type") == "text/turtle" :
#prefixes = _get_prefixes_in_turtle()
#content = _get_literal(node)
#rdf = StringIO(prefixes + content)
content = _get_literal(node)
rdf = StringIO(content)
try :
graph.parse(rdf, format="n3", publicID = state.base)
state.options.add_info("The output graph includes triples coming from an embedded Turtle script")
except :
(type,value,traceback) = sys.exc_info()
state.options.add_error("Embedded Turtle content could not be parsed (problems with %s?); ignored" % value)
return True
elif state.options.host_language in accept_embedded_rdf_xml and node.localName == "RDF" and node.namespaceURI == "http://www.w3.org/1999/02/22-rdf-syntax-ns#" :
rdf = StringIO(return_XML(state, node))
try :
graph.parse(rdf)
state.options.add_info("The output graph includes triples coming from an embedded RDF/XML subtree")
except :
(type,value,traceback) = sys.exc_info()
state.options.add_error("Embedded RDF/XML content could not parsed (problems with %s?); ignored" % value)
return True
else :
return False
else :
return False