001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.servlet.view.tiles3;
018
019import org.apache.tiles.TilesException;
020import org.apache.tiles.preparer.ViewPreparer;
021import org.apache.tiles.preparer.factory.PreparerFactory;
022import org.apache.tiles.request.Request;
023
024import org.springframework.web.context.WebApplicationContext;
025import org.springframework.web.servlet.DispatcherServlet;
026
027/**
028 * Abstract implementation of the Tiles {@link org.apache.tiles.preparer.PreparerFactory}
029 * interface, obtaining the current Spring WebApplicationContext and delegating to
030 * {@link #getPreparer(String, org.springframework.web.context.WebApplicationContext)}.
031 *
032 * @author Juergen Hoeller
033 * @since 3.2
034 * @see #getPreparer(String, org.springframework.web.context.WebApplicationContext)
035 * @see SimpleSpringPreparerFactory
036 * @see SpringBeanPreparerFactory
037 */
038public abstract class AbstractSpringPreparerFactory implements PreparerFactory {
039
040        @Override
041        public ViewPreparer getPreparer(String name, Request context) {
042                WebApplicationContext webApplicationContext = (WebApplicationContext) context.getContext("request").get(
043                                DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE);
044                if (webApplicationContext == null) {
045                        webApplicationContext = (WebApplicationContext) context.getContext("application").get(
046                                        WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
047                        if (webApplicationContext == null) {
048                                throw new IllegalStateException("No WebApplicationContext found: no ContextLoaderListener registered?");
049                        }
050                }
051                return getPreparer(name, webApplicationContext);
052        }
053
054        /**
055         * Obtain a preparer instance for the given preparer name,
056         * based on the given Spring WebApplicationContext.
057         * @param name the name of the preparer
058         * @param context the current Spring WebApplicationContext
059         * @return the preparer instance
060         * @throws TilesException in case of failure
061         */
062        protected abstract ViewPreparer getPreparer(String name, WebApplicationContext context) throws TilesException;
063
064}