/*
* eXist Open Source Native XML Database
* Copyright (C) 2000-2007 The eXist team
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.xquery.functions.fn;
import org.exist.Namespaces;
import org.exist.dom.QName;
import org.exist.xquery.BasicFunction;
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.BooleanValue;
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.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.w3c.dom.Node;
/**
* Built-in function fn:last().
*
* @author wolf
*/
public class FunNilled extends BasicFunction {
public final static FunctionSignature signature =
new FunctionSignature(
new QName("nilled", Function.BUILTIN_FUNCTION_NS),
"Returns an xs:boolean indicating whether the argument node is \"nilled\". " +
"If the argument is not an element node, returns the empty sequence. " +
"If the argument is the empty sequence, returns the empty sequence.",
new SequenceType[] { new FunctionParameterSequenceType("arg", Type.NODE, Cardinality.ZERO_OR_ONE, "The input node") },
new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.ZERO_OR_ONE, "true if the argument node is \"nilled\""));
public FunNilled(XQueryContext context) {
super(context, signature);
}
public Sequence eval(Sequence[] args, Sequence contextSequence) 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);}
}
Sequence result;
if (args[0].isEmpty())
{result = Sequence.EMPTY_SEQUENCE;}
else {
final Item arg = args[0].itemAt(0);
if (!Type.subTypeOf(arg.getType(), Type.ELEMENT))
{result = Sequence.EMPTY_SEQUENCE;}
else {
final Node n = ((NodeValue)arg).getNode();
//TODO : think more...
if (n.hasAttributes()) {
final Node nilled = n.getAttributes().getNamedItemNS(Namespaces.SCHEMA_INSTANCE_NS, "nil");
if (nilled != null)
{result = new BooleanValue(nilled.getNodeValue() == "false");}
else
{result = BooleanValue.FALSE;}
} else
{result = BooleanValue.FALSE;}
}
}
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", result);}
return result;
}
}