/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2009 The eXist Project
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.xquery.functions.fn;
import org.exist.dom.QName;
import org.exist.dom.QNameable;
import org.exist.xquery.Cardinality;
import org.exist.xquery.Dependency;
import org.exist.xquery.ErrorCodes;
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.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.StringValue;
import org.exist.xquery.value.Type;
import org.w3c.dom.Node;
/**
* xpath-library function: name()
*
*/
public class FunName extends Function {
protected static final String FUNCTION_DESCRIPTION_0_PARAM =
"Returns the name of the context item as an xs:string that is either " +
"the zero-length string, or has the lexical form of an xs:QName.\n\n";
protected static final String FUNCTION_DESCRIPTION_1_PARAM =
"Returns the name of $arg as an xs:string that is either " +
"the zero-length string, or has the lexical form of an xs:QName.\n\n" +
"If the argument is omitted, it defaults to the context item (.). ";
protected static final String FUNCTION_DESCRIPTION_COMMON =
"The behavior of the function if the argument is omitted is exactly " +
"the same as if the context item had been passed as the argument.\n\n" +
"The following errors may be raised: if the context item is undefined " +
"[err:XPDY0002]XP; if the context item is not a node [err:XPTY0004]XP.\n\n" +
"If the argument is supplied and is the empty sequence, the function " +
"returns the zero-length string.\n\n" +
"If the target node has no name (that is, if it is a document node, a comment, " +
"a text node, or a namespace binding having no name), the function returns " +
"the zero-length string.\n\n" +
"Otherwise, the value returned is fn:string(fn:node-name($arg)).";
public final static FunctionSignature signatures[] = {
new FunctionSignature(
new QName("name", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION_0_PARAM + FUNCTION_DESCRIPTION_COMMON,
new SequenceType[0],
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "the name")
),
new FunctionSignature(
new QName("name", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION_1_PARAM + FUNCTION_DESCRIPTION_COMMON,
new SequenceType[] { new FunctionParameterSequenceType("arg", Type.NODE, Cardinality.ZERO_OR_ONE, "The input node") },
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "the name")
)
};
public FunName(XQueryContext context, FunctionSignature signature) {
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 seq;
Sequence result;
if (contextItem != null)
{contextSequence = contextItem.toSequence();}
/*
if (contextSequence == null || contextSequence.isEmpty())
result = Sequence.EMPTY_SEQUENCE;
*/
//If we have one argument, we take it into account
if (getSignature().getArgumentCount() > 0)
{seq = getArgument(0).eval(contextSequence, contextItem);}
//Otherwise, we take the context sequence and we iterate over it
else
{seq = contextSequence;}
if (seq == null)
{throw new XPathException(this, ErrorCodes.XPDY0002, "Undefined context item");}
if (seq.isEmpty())
//Bloody specs !
{result = StringValue.EMPTY_STRING;}
else {
final Item item = seq.itemAt(0);
if (!Type.subTypeOf(item.getType(), Type.NODE))
{throw new XPathException(this, ErrorCodes.XPTY0004, "item is not a node; got '" + Type.getTypeName(item.getType()) + "'");}
//TODO : how to improve performance ?
final Node n = ((NodeValue)item).getNode();
if (n instanceof QNameable)
{result = new StringValue(((QNameable)n).getQName().getStringValue());}
else
{result = StringValue.EMPTY_STRING;}
}
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", result);}
return result;
}
}