Mercurial > hg > openjdk > jdk9 > jaxp
view src/java.xml/share/classes/com/sun/org/apache/xpath/internal/operations/VariableSafeAbsRef.java @ 1113:2fdbfbde3bc0
8162572: Update License Header for all JAXP sources
Reviewed-by: lancea
author | joehw |
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date | Mon, 17 Apr 2017 16:24:10 -0700 |
parents | 2bfaf29cc90b |
children |
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/* * reserved comment block * DO NOT REMOVE OR ALTER! */ /* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. */ package com.sun.org.apache.xpath.internal.operations; import com.sun.org.apache.xml.internal.dtm.DTMManager; import com.sun.org.apache.xpath.internal.Expression; import com.sun.org.apache.xpath.internal.XPathContext; import com.sun.org.apache.xpath.internal.objects.XNodeSet; import com.sun.org.apache.xpath.internal.objects.XObject; /** * This is a "smart" variable reference that is used in situations where * an absolute path is optimized into a variable reference, but may * be used in some situations where the document context may have changed. * For instance, in select="document(doc/@href)//name[//salary > 7250]", the * root in the predicate will be different for each node in the set. While * this is easy to detect statically in this case, in other cases static * detection would be very hard or impossible. So, this class does a dynamic check * to make sure the document context of the referenced variable is the same as * the current document context, and, if it is not, execute the referenced variable's * expression with the current context instead. */ public class VariableSafeAbsRef extends Variable { static final long serialVersionUID = -9174661990819967452L; /** * Dereference the variable, and return the reference value. Note that lazy * evaluation will occur. If a variable within scope is not found, a warning * will be sent to the error listener, and an empty nodeset will be returned. * * * @param xctxt The runtime execution context. * * @return The evaluated variable, or an empty nodeset if not found. * * @throws javax.xml.transform.TransformerException */ public XObject execute(XPathContext xctxt, boolean destructiveOK) throws javax.xml.transform.TransformerException { XNodeSet xns = (XNodeSet)super.execute(xctxt, destructiveOK); DTMManager dtmMgr = xctxt.getDTMManager(); int context = xctxt.getContextNode(); if(dtmMgr.getDTM(xns.getRoot()).getDocument() != dtmMgr.getDTM(context).getDocument()) { Expression expr = (Expression)xns.getContainedIter(); xns = (XNodeSet)expr.asIterator(xctxt, context); } return xns; } }