/*
* 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 java.util.Map;
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.AnyURIValue;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.NodeValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
public class FunNamespaceURIForPrefix extends BasicFunction {
protected static final String FUNCTION_DESCRIPTION =
"Returns the namespace URI of one of the in-scope namespaces " +
"for $element, identified by its namespace prefix.\n\n" +
"If $element has an in-scope namespace whose namespace prefix " +
"is equal to $prefix, it returns the namespace URI of that namespace. " +
"If $prefix is the zero-length string or the empty sequence, it " +
"returns the namespace URI of the default (unnamed) namespace. " +
"Otherwise, it returns the empty sequence.\n\n" +
"Prefixes are equal only if their Unicode code points match exactly.";
public final static FunctionSignature signature =
new FunctionSignature(
new QName("namespace-uri-for-prefix", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION,
new SequenceType[] {
new FunctionParameterSequenceType("prefix", Type.STRING, Cardinality.ZERO_OR_ONE, "The namespace prefix"),
new FunctionParameterSequenceType("element", Type.ELEMENT, Cardinality.EXACTLY_ONE, "The element")
},
new FunctionReturnSequenceType(Type.ANY_URI, Cardinality.ZERO_OR_ONE, "the namespace URI"));
public FunNamespaceURIForPrefix(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);}
}
String prefix;
if (args[0].isEmpty())
{prefix = "";}
else
{prefix = args[0].itemAt(0).getStringValue();}
String namespace;
if ("xml".equals(prefix)) {
namespace = Namespaces.XML_NS;
} else {
final Map<String, String> prefixes = FunInScopePrefixes.collectPrefixes(context, (NodeValue) args[1].itemAt(0));
namespace = prefixes.get(prefix);
}
Sequence result;
if (namespace == null)
{result = Sequence.EMPTY_SEQUENCE;}
else
{result = new AnyURIValue(namespace);}
if (context.getProfiler().isEnabled())
{context.getProfiler().end(this, "", result);}
return result;
}
}