/*
* @(#)$Id: InScopePrefixes.java 3619 2008-03-26 07:23:03Z yui $
*
* Copyright 2006-2008 Makoto YUI
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Contributors:
* Makoto YUI - initial implementation
*/
package xbird.xquery.func.qname;
import java.util.ArrayList;
import java.util.List;
import xbird.xquery.XQueryException;
import xbird.xquery.dm.NodeKind;
import xbird.xquery.dm.value.*;
import xbird.xquery.dm.value.literal.XString;
import xbird.xquery.dm.value.sequence.ValueSequence;
import xbird.xquery.func.BuiltInFunction;
import xbird.xquery.func.FunctionSignature;
import xbird.xquery.meta.DynamicContext;
import xbird.xquery.type.Type;
import xbird.xquery.type.TypeRegistry;
import xbird.xquery.type.node.ElementTest;
/**
* fn:in-scope-prefixes($element as element()) as xs:string*.
* <DIV lang="en">
* Returns the prefixes of the in-scope namespaces for $element.
* </DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
* @link http://www.w3.org/TR/xquery-operators/#func-in-scope-prefixes
*/
public final class InScopePrefixes extends BuiltInFunction {
private static final long serialVersionUID = 4944394253347281633L;
public static final String SYMBOL = "fn:in-scope-prefixes";
public InScopePrefixes() {
super(SYMBOL, TypeRegistry.safeGet("xs:string*"));
}
protected FunctionSignature[] signatures() {
final FunctionSignature[] s = new FunctionSignature[1];
s[0] = new FunctionSignature(getName(), new Type[] { ElementTest.ANY_ELEMENT });
return s;
}
public Sequence eval(Sequence<? extends Item> contextSeq, ValueSequence argv, DynamicContext dynEnv) throws XQueryException {
assert (argv != null && argv.size() == 1);
Item firstItem = argv.getItem(0);
XQNode element = (XQNode) firstItem;
assert (element.nodeKind() == NodeKind.ELEMENT);
List<XString> prefixes = new ArrayList<XString>(12);
for(XQNode curNode = element; curNode != null; curNode = curNode.parent()) {
String prefixStr = curNode.nodeName().getPrefix();
if(prefixStr == null) {
prefixStr = "";
}
XString prefix = XString.valueOf(prefixStr);
if(!prefixes.contains(prefix)) {
prefixes.add(prefix);
}
}
if(prefixes.isEmpty()) {
return ValueSequence.EMPTY_SEQUENCE;
}
return new ValueSequence(prefixes, dynEnv);
}
}