/*

  * Copyright 2007 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.kns.web.servlet.dwr;

 import javax.servlet.ServletContext;

 import javax.servlet.http.HttpServletRequest;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.resourceloader.GlobalResourceLoader;

 import org.springframework.beans.factory.BeanFactory;

 import org.springframework.web.context.support.WebApplicationContextUtils;

 import org.springframework.web.servlet.support.RequestContextUtils;

 import uk.ltd.getahead.dwr.Messages;

 import uk.ltd.getahead.dwr.WebContextFactory;

 import uk.ltd.getahead.dwr.create.SpringCreator;

 /**

  * A {@link SpringCreator} that checks the {@link GlobalResourceLoader} for the

  * bean name in question if the default {@link BeanFactory} (the applications)

  * does not have the bean in question.

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  * 

  */

 public class GlobalResourceDelegatingSpringCreator extends SpringCreator {

         private static final Logger LOG = Logger.getLogger(GlobalResourceDelegatingSpringCreator.class);

         private BeanFactory factory;

         public static BeanFactory APPLICATION_BEAN_FACTORY;

         @Override

         /*

          * This is largely ripped from the super class. Implementation details

          * prevent calling the super class and then going to the

          * GlobalResourceLoader ( the BeanFactory wll throw an exception if the bean

          * isn't there). The defalt SpringCreator's static BeanFactory override

          * could not be used - what a pity.

          * 

          */

         public Object getInstance() throws InstantiationException {

                 if (factory == null) {

                         factory = getBeanFactory();

                 }

                 if (factory == null) {

                         factory = APPLICATION_BEAN_FACTORY;

                 }

                 //we could just delegation to the GRL here no need for a resource factory

                 if (factory == null) {

                         LOG.error("DWR can't find a spring config. See following info logs for solutions"); //$NON-NLS-1$

                         LOG.info("- Option 1. In dwr.xml, <create creator='spring' ...> add <param name='location1' value='beans.xml'/> for each spring config file."); //$NON-NLS-1$

                         LOG.info("- Option 2. Use a spring org.springframework.web.context.ContextLoaderListener."); //$NON-NLS-1$

                         LOG.info("- Option 3. Call SpringCreator.setOverrideBeanFactory() from your web-app"); //$NON-NLS-1$

                         throw new InstantiationException(Messages.getString("SpringCreator.MissingConfig")); //$NON-NLS-1$

                 }

                 if (factory.containsBean(this.getBeanName())) {

                         return factory.getBean(this.getBeanName());

                 } else {

                         Object bean = GlobalResourceLoader.getService(this.getBeanName());

                         if (bean == null) {

                                 throw new InstantiationException("Unable to find bean " + this.getBeanName() + " in Rice Global Resource Loader");

                         }

                         return bean;

                 }

         }

         /**

          * @return A found BeanFactory configuration

          */

         private BeanFactory getBeanFactory() {

                 ServletContext srvCtx = WebContextFactory.get().getServletContext();

                 HttpServletRequest request = WebContextFactory.get().getHttpServletRequest();

                 if (request != null) {

                         return RequestContextUtils.getWebApplicationContext(request, srvCtx);

                 } else {

                         return WebApplicationContextUtils.getWebApplicationContext(srvCtx);

                 }

         }

 }