| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 1999-2003 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Xalan" and "Apache Software Foundation" must |
| * not be used to endorse or promote products derived from this |
| * software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * nor may "Apache" appear in their name, without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation and was |
| * originally based on software copyright (c) 1999, Lotus |
| * Development Corporation., http://www.lotus.com. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.xpath.axes; |
| |
| import org.apache.xpath.Expression; |
| import org.apache.xpath.ExpressionOwner; |
| import org.apache.xpath.XPathVisitor; |
| import org.apache.xpath.functions.FuncLast; |
| import org.apache.xpath.functions.FuncPosition; |
| import org.apache.xpath.functions.Function; |
| import org.apache.xpath.objects.XNumber; |
| import org.apache.xpath.operations.Div; |
| import org.apache.xpath.operations.Minus; |
| import org.apache.xpath.operations.Mod; |
| import org.apache.xpath.operations.Mult; |
| import org.apache.xpath.operations.Plus; |
| import org.apache.xpath.operations.Quo; |
| import org.apache.xpath.operations.Variable; |
| |
| public class HasPositionalPredChecker extends XPathVisitor |
| { |
| private boolean m_hasPositionalPred = false; |
| private int m_predDepth = 0; |
| |
| /** |
| * Process the LocPathIterator to see if it contains variables |
| * or functions that may make it context dependent. |
| * @param path LocPathIterator that is assumed to be absolute, but needs checking. |
| * @return true if the path is confirmed to be absolute, false if it |
| * may contain context dependencies. |
| */ |
| public static boolean check(LocPathIterator path) |
| { |
| HasPositionalPredChecker hppc = new HasPositionalPredChecker(); |
| path.callVisitors(null, hppc); |
| return hppc.m_hasPositionalPred; |
| } |
| |
| /** |
| * Visit a function. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param func The function reference object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitFunction(ExpressionOwner owner, Function func) |
| { |
| if((func instanceof FuncPosition) || |
| (func instanceof FuncLast)) |
| m_hasPositionalPred = true; |
| return true; |
| } |
| |
| // /** |
| // * Visit a variable reference. |
| // * @param owner The owner of the expression, to which the expression can |
| // * be reset if rewriting takes place. |
| // * @param var The variable reference object. |
| // * @return true if the sub expressions should be traversed. |
| // */ |
| // public boolean visitVariableRef(ExpressionOwner owner, Variable var) |
| // { |
| // m_hasPositionalPred = true; |
| // return true; |
| // } |
| |
| /** |
| * Visit a predicate within a location path. Note that there isn't a |
| * proper unique component for predicates, and that the expression will |
| * be called also for whatever type Expression is. |
| * |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param pred The predicate object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitPredicate(ExpressionOwner owner, Expression pred) |
| { |
| m_predDepth++; |
| |
| if(m_predDepth == 1) |
| { |
| if((pred instanceof Variable) || |
| (pred instanceof XNumber) || |
| (pred instanceof Div) || |
| (pred instanceof Plus) || |
| (pred instanceof Minus) || |
| (pred instanceof Mod) || |
| (pred instanceof Quo) || |
| (pred instanceof Mult) || |
| (pred instanceof org.apache.xpath.operations.Number) || |
| (pred instanceof Function)) |
| m_hasPositionalPred = true; |
| else |
| pred.callVisitors(owner, this); |
| } |
| |
| m_predDepth--; |
| |
| // Don't go have the caller go any further down the subtree. |
| return false; |
| } |
| |
| |
| } |
| |