org.apache.xalan.templates.AbsPathChecker Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of xalan Show documentation

Xalan-Java is an XSLT processor for transforming XML documents into HTML, text, or other XML document types. It implements XSL Transformations (XSLT) Version 1.0 and XML Path Language (XPath) Version 1.0 and can be used from the command line, in an applet or a servlet, or as a module in other program.

There is a newer version: 2.7.3

Show newest version

/*
 * 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.
 */
/*
 * $Id: AbsPathChecker.java 468643 2006-10-28 06:56:03Z minchau $
 */
package org.apache.xalan.templates;

import org.apache.xpath.ExpressionOwner;
import org.apache.xpath.XPathVisitor;
import org.apache.xpath.axes.LocPathIterator;
import org.apache.xpath.functions.FuncCurrent;
import org.apache.xpath.functions.FuncExtFunction;
import org.apache.xpath.functions.Function;
import org.apache.xpath.operations.Variable;

/**
 * This class runs over a path expression that is assumed to be absolute, and 
 * checks for variables and the like that may make it context dependent.
 */
public class AbsPathChecker extends XPathVisitor
{
	private boolean m_isAbs = true;
	
	/**
	 * 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 boolean checkAbsolute(LocPathIterator path)
	{
		m_isAbs = true;
		path.callVisitors(null, this);
		return m_isAbs;
	}
	
	/**
	 * 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 FuncCurrent) ||
		   (func instanceof FuncExtFunction))
			m_isAbs = false;
		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_isAbs = false;
		return true;
	}
}