- /*
- * 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;
- }
-
-
- }
-