- /*
- * The Apache Software License, Version 1.1
- *
- *
- * Copyright (c) 1999 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.xalan.extensions;
-
- import java.util.Vector;
- import java.lang.reflect.Method;
-
- import java.io.IOException;
-
- import javax.xml.transform.TransformerException;
-
- import org.w3c.dom.Element;
- import org.w3c.dom.Node;
-
- import org.apache.xalan.templates.Stylesheet;
- import org.apache.xalan.templates.ElemTemplateElement;
- import org.apache.xml.utils.QName;
-
- // Temp??
- import org.apache.xalan.transformer.TransformerImpl;
-
- /**
- * <meta name="usage" content="internal"/>
- * Abstract base class for handling an extension namespace for XPath.
- * Provides functions to test a function's existence and call a function.
- * Also provides functions for calling an element and testing for
- * an element's existence.
- *
- * @author Sanjiva Weerawarana (sanjiva@watson.ibm.com)
- */
- public abstract class ExtensionHandler
- {
-
- /** uri of the extension namespace */
- protected String m_namespaceUri;
-
- /** scripting language of implementation */
- protected String m_scriptLang;
-
- /** a zero length Object array used in getClassForName() */
- private static final Object NO_OBJS[] = new Object[0];
-
- /** the Method object for getContextClassLoader */
- private static Method getCCL;
-
- static
- {
- try
- {
- getCCL = Thread.class.getMethod("getContextClassLoader", new Class[0]);
- }
- catch (Exception e)
- {
- getCCL = null;
- }
- }
-
- /**
- * Replacement for Class.forName. This method loads a class using the context class loader
- * if we're running under Java2 or higher. If we're running under Java1, this
- * method just uses Class.forName to load the class.
- *
- * @param className Name of the class to load
- */
- public static Class getClassForName(String className)
- throws ClassNotFoundException
- {
- Class result = null;
-
- // Hack for backwards compatibility with XalanJ1 stylesheets
- if(className.equals("org.apache.xalan.xslt.extensions.Redirect"))
- className = "org.apache.xalan.lib.Redirect";
-
- if (getCCL != null)
- {
- try {
- ClassLoader contextClassLoader =
- (ClassLoader) getCCL.invoke(Thread.currentThread(), NO_OBJS);
- result = contextClassLoader.loadClass(className);
- }
- catch (ClassNotFoundException cnfe)
- {
- result = Class.forName(className);
- }
- catch (Exception e)
- {
- getCCL = null;
- result = Class.forName(className);
- }
- }
-
- else
- result = Class.forName(className);
-
- return result;
- }
-
-
- /**
- * Construct a new extension namespace handler given all the information
- * needed.
- *
- * @param namespaceUri the extension namespace URI that I'm implementing
- * @param scriptLang language of code implementing the extension
- */
- protected ExtensionHandler(String namespaceUri, String scriptLang)
- {
- m_namespaceUri = namespaceUri;
- m_scriptLang = scriptLang;
- }
-
- /**
- * Tests whether a certain function name is known within this namespace.
- * @param function name of the function being tested
- * @return true if its known, false if not.
- */
- public abstract boolean isFunctionAvailable(String function);
-
- /**
- * Tests whether a certain element name is known within this namespace.
- * @param function name of the function being tested
- *
- * @param element Name of element to check
- * @return true if its known, false if not.
- */
- public abstract boolean isElementAvailable(String element);
-
- /**
- * Process a call to a function.
- *
- * @param funcName Function name.
- * @param args The arguments of the function call.
- * @param methodKey A key that uniquely identifies this class and method call.
- * @param exprContext The context in which this expression is being executed.
- *
- * @return the return value of the function evaluation.
- *
- * @throws TransformerException if parsing trouble
- */
- public abstract Object callFunction(
- String funcName, Vector args, Object methodKey,
- ExpressionContext exprContext) throws TransformerException;
-
- /**
- * Process a call to this extension namespace via an element. As a side
- * effect, the results are sent to the TransformerImpl's result tree.
- *
- * @param localPart Element name's local part.
- * @param element The extension element being processed.
- * @param transformer Handle to TransformerImpl.
- * @param stylesheetTree The compiled stylesheet tree.
- * @param mode The current mode.
- * @param sourceTree The root of the source tree (but don't assume
- * it's a Document).
- * @param sourceNode The current context node.
- * @param methodKey A key that uniquely identifies this class and method call.
- *
- * @throws XSLProcessorException thrown if something goes wrong
- * while running the extension handler.
- * @throws MalformedURLException if loading trouble
- * @throws FileNotFoundException if loading trouble
- * @throws IOException if loading trouble
- * @throws TransformerException if parsing trouble
- */
- public abstract void processElement(
- String localPart, ElemTemplateElement element, TransformerImpl transformer,
- Stylesheet stylesheetTree, Object methodKey) throws TransformerException, IOException;
- }