Hi, since the SPARQL xml-writer didnt work for me either I re-made the implementation using elementtree (attached). For versions before 2.5 it is possible to fall-back on the ElementTree package. This code has been used with rdflib 2.4.0 and its probably broken on trunk. I could test a variant of this against trunk if anyone is interested?
Cheers, Mikael On 09/08/07, Chimezie Ogbuji <[EMAIL PROTECTED]> wrote: > On 8/9/07, whit <[EMAIL PROTECTED]> wrote: > > +1 (to elementree and to the use of lxml in plugins) > > > > I would encourage introducing no new dependencies outside of what can be > > isolated inside a plugin (dunno if john's changes fall into that category) > > and disable any related tests if the dependency is unavailable. Special > > dependency code also should not hide the fallback implementation from tests; > > a conditional import rendered the standard sparql xmlwriter and it's > > brokeness hidden from those with Ft installed for a quite awhile on trunk. > > FYI: The brokeness of the 'standard' sparql xmlwriter had all to do > with the poor capability of native Python SAX writing - which couldn't > even handle namespaces properly! I was also unable to use RDFLib's > XMLWriter for that purpose as well - for reasons similar to John's. > > I have been working with an updated version of a harness for the (new) > W3C DAWG tests for SPARQL but have not checked it in (and probably > won't) mostly because it required additional XML processing I was > simply unable to perform with 'native' Python: comparing SPARQL > results against expected test results, for instance. In addition, I > also needed Ft.Lib.Uri to do 'proper' RFC-compliant resolution of URIs > (for which the 'native' capabilities of urllib/urllib2 are broken in > many regards). URI resolution is a *major* component of SPARQL. > > I'm not so familiar with ElementTree or lxml (mostly because I've been > spoiled by 4Suite for so long). A seperate question: a dependence on > ElementTree bumps the overall dependency to Py2.5, is that where we > want to be? If so, I would be curious to find out what aspects of XML > processing can be done with lxml and which of those are crucial to RDF > processing. > _______________________________________________ > Dev mailing list > Dev@rdflib.net > http://rdflib.net/mailman/listinfo/dev >
# -*- coding: iso-8859-15 -*- # (c) Mikael Högqvist, ZIB, AstroGrid-D # This software is licensed under the software license specified at # http://www.gac-grid.org/ # this is a work-around of the SPARQL XML-serialization in rdflib which does # not work on all installation due to a bug in the python sax-parser # We rely on ElementTree which is only available in Python 2.5 from cStringIO import StringIO try: from xml.etree.cElementTree import Element, SubElement, ElementTree, ProcessingInstruction import xml.etree.cElementTree as ET except ImportError: from cElementTree import Element, SubElement, ElementTree import cElementTree as ET from rdflib import URIRef, BNode, Literal SPARQL_XML_NAMESPACE = u'http://www.w3.org/2005/sparql-results#' XML_NAMESPACE = "http://www.w3.org/2001/XMLSchema#"; name = lambda elem: u'{%s}%s' % (SPARQL_XML_NAMESPACE, elem) xml_name = lambda elem: u'{%s}%s' % (XML_NAMESPACE, elem) def variables(results): # don't include any variables which are not part of the # result set #res_vars = set(results.selectionF).intersection(set(results.allVariables)) # this means select *, use all variables from the result-set if len(results.selectionF) == 0: res_vars = results.allVariables else: res_vars = [v for v in results.selectionF if v in results.allVariables] return res_vars def header(results, root): head = SubElement(root, name(u'head')) res_vars = variables(results) for var in res_vars: v = SubElement(head, name(u'variable')) # remove the ? v.attrib[u'name'] = var[1:] def binding(val, var, elem): bindingElem = SubElement(elem, name(u'binding')) bindingElem.attrib[u'name'] = var if isinstance(val,URIRef): varElem = SubElement(bindingElem, name(u'uri')) elif isinstance(val,BNode) : varElem = SubElement(bindingElem, name(u'bnode')) elif isinstance(val,Literal): varElem = SubElement(bindingElem, name(u'literal')) if val.language != "" and val.language != None: varElem.attrib[xml_name(u'lang')] = str(val.language) elif val.datatype != "" and val.datatype != None: varElem.attrib[name(u'datatype')] = str(val.datatype) varElem.text = str(val) def res_iter(results): res_vars = variables(results) for row in results.selected: if len(res_vars) == 1: row = (row, ) yield zip(row, res_vars) def result_list(results, root): resultsElem = SubElement(root, name(u'results')) ordered = results.orderBy if ordered == None: ordered = False # removed according to the new working draft (2007-06-14) # resultsElem.attrib[u'ordered'] = str(ordered) # resultsElem.attrib[u'distinct'] = str(results.distinct) for row in res_iter(results): resultElem = SubElement(resultsElem, name(u'result')) # remove the ? from the variable name [binding(val, var[1:], resultElem) for (val, var) in row] def serializeXML(results): root = Element(name(u'sparql')) header(results, root) result_list(results, root) out = StringIO() tree = ElementTree(root) # xml declaration must be written by hand # http://www.nabble.com/Writing-XML-files-with-ElementTree-t3433325.html out.write('<?xml version="1.0" encoding="utf-8"?>') out.write('<?xml-stylesheet type="text/xsl" href="/static/sparql-xml-to-html.xsl"?>') tree.write(out, encoding='utf-8') return out.getvalue()
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