| /* |
| * $Id$ |
| * |
| * 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. |
| */ |
| |
| package org.apache.tiles.request.freemarker.servlet; |
| |
| import java.util.Enumeration; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| |
| import javax.servlet.ServletConfig; |
| import javax.servlet.ServletContext; |
| import javax.servlet.ServletException; |
| |
| import org.apache.tiles.request.reflect.ClassUtil; |
| |
| import freemarker.cache.TemplateLoader; |
| import freemarker.ext.servlet.FreemarkerServlet; |
| import freemarker.template.Configuration; |
| |
| /** |
| * Extends FreemarkerServlet to load Tiles directives as a shared variable. |
| * |
| * @version $Rev$ $Date$ |
| */ |
| public class SharedVariableLoaderFreemarkerServlet extends FreemarkerServlet { |
| |
| /** |
| * The serial UID. |
| */ |
| private static final long serialVersionUID = 4301098067909854507L; |
| |
| /** |
| * The init parameter under which the factories will be put. The value of the parameter |
| * must be a semicolon (;) separated list of couples, each member of the couple must |
| * be separated by commas (,). |
| */ |
| public static final String CUSTOM_SHARED_VARIABLE_FACTORIES_INIT_PARAM = |
| "org.apache.tiles.request.freemarker.CUSTOM_SHARED_VARIABLE_FACTORIES"; |
| |
| /** |
| * Maps a name of a shared variable to its factory. |
| */ |
| private Map<String, SharedVariableFactory> name2variableFactory = |
| new LinkedHashMap<String, SharedVariableFactory>(); |
| |
| @Override |
| public void init(ServletConfig config) throws ServletException { |
| String param = config.getInitParameter(CUSTOM_SHARED_VARIABLE_FACTORIES_INIT_PARAM); |
| if (param != null) { |
| String[] couples = param.split("\\s*;\\s*"); |
| for (int i = 0; i < couples.length; i++) { |
| String[] couple = couples[i].split("\\s*,\\s*"); |
| if (couple == null || couple.length != 2) { |
| throw new ServletException( |
| "Cannot parse custom shared variable partial init param: '" |
| + couples[i] + "'"); |
| } |
| name2variableFactory.put(couple[0], |
| (SharedVariableFactory) ClassUtil.instantiate(couple[1])); |
| } |
| } |
| super.init(new ExcludingParameterServletConfig(config)); |
| } |
| |
| /** |
| * Adds anew shared variable factory in a manual way. |
| * |
| * @param variableName The name of the shared variable. |
| * @param factory The shared variable factory. |
| */ |
| public void addSharedVariableFactory(String variableName, SharedVariableFactory factory) { |
| name2variableFactory.put(variableName, factory); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected Configuration createConfiguration() { |
| Configuration configuration = super.createConfiguration(); |
| |
| for (Map.Entry<String, SharedVariableFactory> entry : name2variableFactory.entrySet()) { |
| configuration.setSharedVariable(entry.getKey(), entry.getValue().create()); |
| } |
| return configuration; |
| } |
| |
| /** {@inheritDoc} */ |
| |
| @Override |
| protected TemplateLoader createTemplateLoader(String templatePath) { |
| return new WebappClassTemplateLoader(getServletContext()); |
| } |
| |
| /** |
| * Servlet configuration that excludes some parameters. It is useful to adapt to |
| * FreemarkerServlet behaviour, because it gets angry if it sees some extra |
| * parameters that it does not recognize. |
| */ |
| private class ExcludingParameterServletConfig implements ServletConfig { |
| |
| /** |
| * The servlet configuration. |
| */ |
| private ServletConfig config; |
| |
| /** |
| * Constructor. |
| * |
| * @param config The servlet configuration. |
| */ |
| public ExcludingParameterServletConfig(ServletConfig config) { |
| this.config = config; |
| } |
| |
| @Override |
| public String getServletName() { |
| return config.getServletName(); |
| } |
| |
| @Override |
| public ServletContext getServletContext() { |
| return config.getServletContext(); |
| } |
| |
| @Override |
| public String getInitParameter(String name) { |
| if (CUSTOM_SHARED_VARIABLE_FACTORIES_INIT_PARAM.equals(name)) { |
| return null; |
| } |
| return config.getInitParameter(name); |
| } |
| |
| @SuppressWarnings({ "rawtypes", "unchecked" }) |
| @Override |
| public Enumeration getInitParameterNames() { |
| return new SkippingEnumeration(config.getInitParameterNames()); |
| } |
| |
| } |
| |
| /** |
| * An enumeration that skip just |
| * {@link SharedVariableLoaderFreemarkerServlet#CUSTOM_SHARED_VARIABLE_FACTORIES_INIT_PARAM}, |
| * again not to let the FreemarkerServlet be angry about it. |
| */ |
| private static class SkippingEnumeration implements Enumeration<String> { |
| |
| /** |
| * The original enumeration. |
| */ |
| private Enumeration<String> enumeration; |
| |
| /** |
| * The next element. |
| */ |
| private String next = null; |
| |
| /** |
| * Constructor. |
| * |
| * @param enumeration The original enumeration. |
| */ |
| public SkippingEnumeration(Enumeration<String> enumeration) { |
| this.enumeration = enumeration; |
| updateNextElement(); |
| } |
| |
| @Override |
| public boolean hasMoreElements() { |
| return next != null; |
| } |
| |
| @Override |
| public String nextElement() { |
| String retValue = next; |
| updateNextElement(); |
| return retValue; |
| } |
| |
| /** |
| * Updates the next element that will be passed. |
| */ |
| private void updateNextElement() { |
| String value = null; |
| boolean done = false; |
| while (this.enumeration.hasMoreElements() && !done) { |
| value = this.enumeration.nextElement(); |
| if (value.equals(CUSTOM_SHARED_VARIABLE_FACTORIES_INIT_PARAM)) { |
| value = null; |
| } else { |
| done = true; |
| } |
| } |
| next = value; |
| } |
| |
| } |
| } |