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<>}.

@author: U{Ivan Herman<a href="">}
@license: This software is available for use under the
@contact: Ivan Herman,
@version: $Id:,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 + # 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 == "" : 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