*/
public static Map<String,SequenceNode> loadXMLSchema(URL url, XMLGraph xg) throws ParseException {
boolean extend = xg != null;
String u = url.toString();
Map<String,SequenceNode> types = new HashMap<String,SequenceNode>();
RNGParser rngparser = new RNGParser();
RestrRelaxNG2XMLGraph rrng2xg = new RestrRelaxNG2XMLGraph(xg, datatypes);
if (u.endsWith(".xsd")) {
XMLSchema2RestrRelaxNG xsd2rrng = new XMLSchema2RestrRelaxNG(datatypes);
if (extend)
rrng2xg.extend(rngparser.parse(xsd2rrng.convert(url), url));
else
xg = rrng2xg.convert(rngparser.parse(xsd2rrng.convert(url), url));
Map<String,String> m1 = xsd2rrng.getNameMap();
Map<String,String> m2 = rngparser.getTopLevelNewNames();
Map<String,SequenceNode> m3 = rrng2xg.getDefineNodes();
for (Map.Entry<String,String> e : m1.entrySet())
types.put(e.getKey(), m3.get(m2.get(e.getValue())));
} else if (u.endsWith(".dtd")) {
DTD2RestrRelaxNG dtd2rrng = new DTD2RestrRelaxNG();
if (extend)
rrng2xg.extend(rngparser.parse(dtd2rrng.convert(url), url));
else
xg = rrng2xg.convert(rngparser.parse(dtd2rrng.convert(url), url));
Map<String,String> m1 = dtd2rrng.getNameMap();
Map<String,String> m2 = rngparser.getTopLevelNewNames();
Map<String,SequenceNode> m3 = rrng2xg.getDefineNodes();
for (Map.Entry<String,String> e : m1.entrySet())
types.put(e.getKey(), m3.get(m2.get(e.getValue())));
} else if (u.endsWith(".rrng") || u.endsWith(".rng")) {
Grammar rrng = rngparser.parse(url);
if (!rrng.check(System.err))
throw new ParseException("Schema is not Restricted RELAX NG " + url);
if (extend)
rrng2xg.extend(rrng);
else
xg = rrng2xg.convert(rrng);
Map<String,String> m1 = rngparser.getTopLevelNewNames();
Map<String,SequenceNode> m2 = rrng2xg.getDefineNodes();
for (Map.Entry<String,String> e : m1.entrySet())
types.put(e.getKey(), m2.get(e.getValue()));
} else
throw new ParseException("Unrecognized schema type " + url);