| /* |
| * 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. |
| */ |
| /* |
| * $Id$ |
| */ |
| package org.apache.xalan.extensions; |
| |
| import java.util.Hashtable; |
| import java.util.Vector; |
| |
| import org.apache.xalan.res.XSLMessages; |
| import org.apache.xalan.res.XSLTErrorResources; |
| import org.apache.xalan.templates.StylesheetRoot; |
| import org.apache.xpath.XPathProcessorException; |
| import org.apache.xpath.functions.FuncExtFunction; |
| |
| /** |
| * Class holding a table registered extension namespace handlers |
| * @xsl.usage internal |
| */ |
| public class ExtensionsTable |
| { |
| /** |
| * Table of extensions that may be called from the expression language |
| * via the call(name, ...) function. Objects are keyed on the call |
| * name. |
| * @xsl.usage internal |
| */ |
| public Hashtable m_extensionFunctionNamespaces = new Hashtable(); |
| |
| /** |
| * The StylesheetRoot associated with this extensions table. |
| */ |
| private StylesheetRoot m_sroot; |
| |
| /** |
| * The constructor (called from TransformerImpl) registers the |
| * StylesheetRoot for the transformation and instantiates an |
| * ExtensionHandler for each extension namespace. |
| * @xsl.usage advanced |
| */ |
| public ExtensionsTable(StylesheetRoot sroot) |
| throws javax.xml.transform.TransformerException |
| { |
| m_sroot = sroot; |
| Vector extensions = m_sroot.getExtensions(); |
| for (int i = 0; i < extensions.size(); i++) |
| { |
| ExtensionNamespaceSupport extNamespaceSpt = |
| (ExtensionNamespaceSupport)extensions.get(i); |
| ExtensionHandler extHandler = extNamespaceSpt.launch(); |
| if (extHandler != null) |
| addExtensionNamespace(extNamespaceSpt.getNamespace(), extHandler); |
| } |
| } |
| |
| /** |
| * Get an ExtensionHandler object that represents the |
| * given namespace. |
| * @param extns A valid extension namespace. |
| * |
| * @return ExtensionHandler object that represents the |
| * given namespace. |
| */ |
| public ExtensionHandler get(String extns) |
| { |
| return (ExtensionHandler) m_extensionFunctionNamespaces.get(extns); |
| } |
| |
| /** |
| * Register an extension namespace handler. This handler provides |
| * functions for testing whether a function is known within the |
| * namespace and also for invoking the functions. |
| * |
| * @param uri the URI for the extension. |
| * @param extNS the extension handler. |
| * @xsl.usage advanced |
| */ |
| public void addExtensionNamespace(String uri, ExtensionHandler extNS) |
| { |
| m_extensionFunctionNamespaces.put(uri, extNS); |
| } |
| |
| /** |
| * Execute the function-available() function. |
| * @param ns the URI of namespace in which the function is needed |
| * @param funcName the function name being tested |
| * |
| * @return whether the given function is available or not. |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| public boolean functionAvailable(String ns, String funcName) |
| throws javax.xml.transform.TransformerException |
| { |
| boolean isAvailable = false; |
| |
| if (null != ns) |
| { |
| ExtensionHandler extNS = |
| (ExtensionHandler) m_extensionFunctionNamespaces.get(ns); |
| if (extNS != null) |
| isAvailable = extNS.isFunctionAvailable(funcName); |
| } |
| return isAvailable; |
| } |
| |
| /** |
| * Execute the element-available() function. |
| * @param ns the URI of namespace in which the function is needed |
| * @param elemName name of element being tested |
| * |
| * @return whether the given element is available or not. |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| public boolean elementAvailable(String ns, String elemName) |
| throws javax.xml.transform.TransformerException |
| { |
| boolean isAvailable = false; |
| if (null != ns) |
| { |
| ExtensionHandler extNS = |
| (ExtensionHandler) m_extensionFunctionNamespaces.get(ns); |
| if (extNS != null) // defensive |
| isAvailable = extNS.isElementAvailable(elemName); |
| } |
| return isAvailable; |
| } |
| |
| /** |
| * Handle an extension function. |
| * @param ns the URI of namespace in which the function is needed |
| * @param funcName the function name being called |
| * @param argVec arguments to the function in a vector |
| * @param methodKey a unique key identifying this function instance in the |
| * stylesheet |
| * @param exprContext a context which may be passed to an extension function |
| * and provides callback functions to access various |
| * areas in the environment |
| * |
| * @return result of executing the function |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| public Object extFunction(String ns, String funcName, |
| Vector argVec, Object methodKey, |
| ExpressionContext exprContext) |
| throws javax.xml.transform.TransformerException |
| { |
| Object result = null; |
| if (null != ns) |
| { |
| ExtensionHandler extNS = |
| (ExtensionHandler) m_extensionFunctionNamespaces.get(ns); |
| if (null != extNS) |
| { |
| try |
| { |
| result = extNS.callFunction(funcName, argVec, methodKey, |
| exprContext); |
| } |
| catch (javax.xml.transform.TransformerException e) |
| { |
| throw e; |
| } |
| catch (Exception e) |
| { |
| throw new javax.xml.transform.TransformerException(e); |
| } |
| } |
| else |
| { |
| throw new XPathProcessorException(XSLMessages.createMessage(XSLTErrorResources.ER_EXTENSION_FUNC_UNKNOWN, new Object[]{ns, funcName })); |
| //"Extension function '" + ns + ":" + funcName + "' is unknown"); |
| } |
| } |
| return result; |
| } |
| |
| /** |
| * Handle an extension function. |
| * @param extFunction the extension function |
| * @param argVec arguments to the function in a vector |
| * @param exprContext a context which may be passed to an extension function |
| * and provides callback functions to access various |
| * areas in the environment |
| * |
| * @return result of executing the function |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| public Object extFunction(FuncExtFunction extFunction, Vector argVec, |
| ExpressionContext exprContext) |
| throws javax.xml.transform.TransformerException |
| { |
| Object result = null; |
| String ns = extFunction.getNamespace(); |
| if (null != ns) |
| { |
| ExtensionHandler extNS = |
| (ExtensionHandler) m_extensionFunctionNamespaces.get(ns); |
| if (null != extNS) |
| { |
| try |
| { |
| result = extNS.callFunction(extFunction, argVec, exprContext); |
| } |
| catch (javax.xml.transform.TransformerException e) |
| { |
| throw e; |
| } |
| catch (Exception e) |
| { |
| throw new javax.xml.transform.TransformerException(e); |
| } |
| } |
| else |
| { |
| throw new XPathProcessorException(XSLMessages.createMessage(XSLTErrorResources.ER_EXTENSION_FUNC_UNKNOWN, |
| new Object[]{ns, extFunction.getFunctionName()})); |
| } |
| } |
| return result; |
| } |
| } |