The following issue has been SUBMITTED. ====================================================================== http://bugs.librdf.org/mantis/view.php?id=593 ====================================================================== Reported By: normang Assigned To: ====================================================================== Project: Raptor RDF Syntax Library Issue ID: 593 Category: api Reproducibility: always Severity: major Priority: normal Status: new Syntax Name: ====================================================================== Date Submitted: 2015-02-02 07:58 Last Modified: 2015-02-02 07:58 ====================================================================== Summary: RDF/XML and RDF/XML-abbrev serialisers produce inconsistent output (and I think the latter is wrong) Description: Consider the following:
% cat xml.ttl @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>. @prefix test: <urn:foo#>. test:foo test:prop "name"; test:value """<greeting>Hello, world!</greeting>"""^^rdf:XMLLiteral. Converting this to RDF/XML produces: % rapper -iturtle -ordfxml xml.ttl rapper: Parsing URI file:///checkouts/me/clouds/latex-and-xmp/xml.ttl with parser turtle rapper: Serializing with serializer rdfxml <?xml version="1.0" encoding="utf-8"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"; xmlns:test="urn:foo#"> <rdf:Description rdf:about="urn:foo#foo"> <test:prop>name</test:prop> </rdf:Description> <rdf:Description rdf:about="urn:foo#foo"> <test:value rdf:parseType="Literal"><greeting>Hello, world!</greeting></test:value> </rdf:Description> </rdf:RDF> rapper: Parsing returned 2 triples But converting it to RDF/XML with abbreviations produces: % rapper -iturtle -ordfxml-abbrev xml.ttl rapper: Parsing URI file:///checkouts/me/clouds/latex-and-xmp/xml.ttl with parser turtle rapper: Serializing with serializer rdfxml-abbrev <?xml version="1.0" encoding="utf-8"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"; xmlns:test="urn:foo#"> <rdf:Description rdf:about="urn:foo#foo"> <test:prop>name</test:prop> <test:value rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral";><greeting>Hello, world!</greeting></test:value> </rdf:Description> </rdf:RDF> rapper: Parsing returned 2 triples % Notice that in the first case, the XML literal appears as a rdf:parseType='Literal' element containing XML elements, but in the second it appears as a string, with the angle brackets escaped. Unfortunately, I'm not _convinced_ I know what should be happening here, but this _does_ appear to be at least inconsistent. The -ordfxml output appears to be correct (comparing it with http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax-XML-literals), and the text of section 7.2.17 appears to indicate that there is no need for any rdf:XMLLiteral typing. The -ordfxml-abbrev output, however, is I think wrong, because it's _different_ XML from what appears in the -ordfxml case: in the rdfxml case, the result is a single 'greeting' element, in the rdfxml-abbrev case, the result is a sequence of characters, which includes (escaped) '<' and '>' characters. This does not strictly contradict http://www.w3.org/TR/rdf11-concepts/#section-XMLLiteral because a sequence of characters _is_ 'XML content', but it is not, I think, the same XML content (ie, an element) that is indicated by """<greeting>Hello, world!</greeting>"""^^rdf:XMLLiteral Raptor is partly consistent, here, because the -ordfxml and -ordfxml-abbrev outputs (and -ordfxml-xmp) produce the same -oturtle output. However the -ordfxml and -ordfxml-abbrev outputs are inconsistent with each other. That is, they can't both be right, and I think it's the rdfxml-abbrev output which is wrong. It's true that the -ordfxml output uses rdf:parseType='Literal', whereas the -ordfxml-abbrev output rdf:datatype="http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral";. I _think_ these are equivalent to each other (the Note in http://www.w3.org/TR/rdf11-concepts/#section-XMLLiteral isn't completely clear); if so, the content should be the same. This last point implies (again, I think) that raptor's parsing of the -ordfxml-abbrev output is incorrect. Referring again to <http://www.w3.org/TR/rdf11-concepts/#section-XMLLiteral>, the content "<greeting..." is indeed in the lexical space of the rdf:XMLLiteral datatype (good), but the lexical-to-value mapping is (the normalized version of) "a DOM DocumentFragment node [DOM4] corresponding to the input string". The problem is that that 'corresponding' is slightly vague, but the only thing I think it can mean is the result of doing an XML parse on the input string (namely "<greeting...") which produces a series of character nodes, not an element. ====================================================================== Issue History Date Modified Username Field Change ====================================================================== 2015-02-02 07:58 normang New Issue ====================================================================== _______________________________________________ redland-dev mailing list redland-dev@lists.librdf.org http://lists.librdf.org/mailman/listinfo/redland-dev
