/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-09 Wolfgang M. Meier
* wolfgang@exist-db.org
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
*/
package org.exist.xquery.functions;
import org.exist.dom.QName;
import org.exist.dom.QNameable;
import org.exist.xquery.Cardinality;
import org.exist.xquery.Dependency;
import org.exist.xquery.Function;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Profiler;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.NodeValue;
import org.exist.xquery.value.QNameValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.w3c.dom.Node;
/**
* Implements the fn:node-name library function.
*
* @author wolf
*/
public class FunNodeName extends Function {
public final static FunctionSignature signature =
new FunctionSignature(
new QName("node-name", Function.BUILTIN_FUNCTION_NS),
"Returns an expanded-QName for node kinds that can have names. For other kinds " +
"of nodes it returns the empty sequence. If $arg is the empty sequence, the " +
"empty sequence is returned.",
new SequenceType[] { new FunctionParameterSequenceType("arg", Type.NODE, Cardinality.ZERO_OR_ONE, "The input node") },
new FunctionReturnSequenceType(Type.QNAME, Cardinality.ZERO_OR_ONE, "the expanded QName"));
/**
* @param context
*/
public FunNodeName(XQueryContext context) {
super(context, signature);
}
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
if (context.getProfiler().isEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if (contextSequence != null)
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);
if (contextItem != null)
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT ITEM", contextItem.toSequence());
}
Sequence result;
Sequence seq = getArgument(0).eval(contextSequence, contextItem);
if(seq.isEmpty())
result = Sequence.EMPTY_SEQUENCE;
else {
Item item = seq.itemAt(0);
if (!Type.subTypeOf(item.getType(), Type.NODE))
throw new XPathException(this, "XPTY0004: item is not a node; got '" + Type.getTypeName(item.getType()) + "'");
//TODO : how to improve performance ?
Node n = ((NodeValue)item).getNode();
//Returns an expanded-QName for node kinds that can have names.
if (n instanceof QNameable) {
QName qn= ((QNameable)n).getQName();
if (qn.equalsSimple(QName.EMPTY_QNAME))
result = Sequence.EMPTY_SEQUENCE;
else
result = new QNameValue(context, qn);
//For other kinds of nodes it returns the empty sequence.
} else
result = Sequence.EMPTY_SEQUENCE;
}
if (context.getProfiler().isEnabled())
context.getProfiler().end(this, "", result);
return result;
}
}