| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 2002 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; |
| |
| import org.apache.xpath.patterns.NodeTest; |
| import org.apache.xpath.axes.LocPathIterator; |
| import org.apache.xpath.axes.UnionPathIterator; |
| import org.apache.xpath.functions.Function; |
| import org.apache.xpath.objects.XNumber; |
| import org.apache.xpath.objects.XString; |
| import org.apache.xpath.operations.Operation; |
| import org.apache.xpath.operations.UnaryOperation; |
| import org.apache.xpath.operations.Variable; |
| import org.apache.xpath.patterns.StepPattern; |
| import org.apache.xpath.patterns.UnionPattern; |
| |
| /** |
| * A derivation from this class can be passed to a class that implements |
| * the XPathVisitable interface, to have the appropriate method called |
| * for each component of the XPath. Aside from possible other uses, the |
| * main intention is to provide a reasonable means to perform expression |
| * rewriting. |
| * |
| * <p>Each method has the form |
| * <code>boolean visitComponentType(ExpressionOwner owner, ComponentType compType)</code>. |
| * The ExpressionOwner argument is the owner of the component, and can |
| * be used to reset the expression for rewriting. If a method returns |
| * false, the sub hierarchy will not be traversed.</p> |
| * |
| * <p>This class is meant to be a base class that will be derived by concrete classes, |
| * and doesn't much except return true for each method.</p> |
| */ |
| public class XPathVisitor |
| { |
| /** |
| * Visit a LocationPath. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param path The LocationPath object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitLocationPath(ExpressionOwner owner, LocPathIterator path) |
| { |
| return true; |
| } |
| |
| /** |
| * Visit a UnionPath. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param path The UnionPath object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitUnionPath(ExpressionOwner owner, UnionPathIterator path) |
| { |
| return true; |
| } |
| |
| /** |
| * Visit a step within a location path. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param step The Step object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitStep(ExpressionOwner owner, NodeTest step) |
| { |
| 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) |
| { |
| return true; |
| } |
| |
| /** |
| * Visit a binary operation. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param op The operation object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitBinaryOperation(ExpressionOwner owner, Operation op) |
| { |
| return true; |
| } |
| |
| /** |
| * Visit a unary operation. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param op The operation object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitUnaryOperation(ExpressionOwner owner, UnaryOperation op) |
| { |
| 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) |
| { |
| return true; |
| } |
| |
| /** |
| * 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) |
| { |
| return true; |
| } |
| |
| /** |
| * Visit a match pattern. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param pattern The match pattern object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitMatchPattern(ExpressionOwner owner, StepPattern pattern) |
| { |
| return true; |
| } |
| |
| /** |
| * Visit a union pattern. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param pattern The union pattern object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitUnionPattern(ExpressionOwner owner, UnionPattern pattern) |
| { |
| return true; |
| } |
| |
| /** |
| * Visit a string literal. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param str The string literal object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitStringLiteral(ExpressionOwner owner, XString str) |
| { |
| return true; |
| } |
| |
| |
| /** |
| * Visit a number literal. |
| * @param owner The owner of the expression, to which the expression can |
| * be reset if rewriting takes place. |
| * @param num The number literal object. |
| * @return true if the sub expressions should be traversed. |
| */ |
| public boolean visitNumberLiteral(ExpressionOwner owner, XNumber num) |
| { |
| return true; |
| } |
| |
| |
| } |
| |