| /* |
| * 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 com.opensymphony.xwork2.interceptor; |
| |
| import com.opensymphony.xwork2.ActionInvocation; |
| import com.opensymphony.xwork2.ModelDriven; |
| import com.opensymphony.xwork2.util.CompoundRoot; |
| import com.opensymphony.xwork2.util.ValueStack; |
| |
| /** |
| * <!-- START SNIPPET: description --> |
| * |
| * Watches for {@link ModelDriven} actions and adds the action's model on to the value stack. |
| * |
| * <p> <b>Note:</b> The ModelDrivenInterceptor must come before the both {@link StaticParametersInterceptor} and |
| * {@link ParametersInterceptor} if you want the parameters to be applied to the model. |
| * </p> |
| * <p> <b>Note:</b> The ModelDrivenInterceptor will only push the model into the stack when the |
| * model is not null, else it will be ignored. |
| * </p> |
| * |
| * <!-- END SNIPPET: description --> |
| * |
| * <p><u>Interceptor parameters:</u></p> |
| * |
| * <!-- START SNIPPET: parameters --> |
| * |
| * <ul> |
| * |
| * <li>refreshModelBeforeResult - set to true if you want the model to be refreshed on the value stack after action |
| * execution and before result execution. The setting is useful if you want to change the model instance during the |
| * action execution phase, like when loading it from the data layer. This will result in getModel() being called at |
| * least twice.</li> |
| * |
| * </ul> |
| * |
| * <!-- END SNIPPET: parameters --> |
| * |
| * <p><u>Extending the interceptor:</u></p> |
| * |
| * <!-- START SNIPPET: extending --> |
| * |
| * There are no known extension points to this interceptor. |
| * |
| * <!-- END SNIPPET: extending --> |
| * |
| * <p><u>Example code:</u></p> |
| * |
| * <pre> |
| * <!-- START SNIPPET: example --> |
| * <action name="someAction" class="com.examples.SomeAction"> |
| * <interceptor-ref name="modelDriven"/> |
| * <interceptor-ref name="basicStack"/> |
| * <result name="success">good_result.ftl</result> |
| * </action> |
| * <!-- END SNIPPET: example --> |
| * </pre> |
| * |
| * @author tm_jee |
| * @version $Date$ $Id$ |
| */ |
| public class ModelDrivenInterceptor extends AbstractInterceptor { |
| |
| protected boolean refreshModelBeforeResult = false; |
| |
| public void setRefreshModelBeforeResult(boolean val) { |
| this.refreshModelBeforeResult = val; |
| } |
| |
| @Override |
| public String intercept(ActionInvocation invocation) throws Exception { |
| Object action = invocation.getAction(); |
| |
| if (action instanceof ModelDriven) { |
| ModelDriven modelDriven = (ModelDriven) action; |
| ValueStack stack = invocation.getStack(); |
| Object model = modelDriven.getModel(); |
| if (model != null) { |
| stack.push(model); |
| } |
| if (refreshModelBeforeResult) { |
| invocation.addPreResultListener(new RefreshModelBeforeResult(modelDriven, model)); |
| } |
| } |
| return invocation.invoke(); |
| } |
| |
| /** |
| * Refreshes the model instance on the value stack, if it has changed |
| */ |
| protected static class RefreshModelBeforeResult implements PreResultListener { |
| private Object originalModel = null; |
| protected ModelDriven action; |
| |
| |
| public RefreshModelBeforeResult(ModelDriven action, Object model) { |
| this.originalModel = model; |
| this.action = action; |
| } |
| |
| public void beforeResult(ActionInvocation invocation, String resultCode) { |
| ValueStack stack = invocation.getStack(); |
| CompoundRoot root = stack.getRoot(); |
| |
| boolean needsRefresh = true; |
| Object newModel = action.getModel(); |
| |
| // Check to see if the new model instance is already on the stack |
| for (Object item : root) { |
| if (item.equals(newModel)) { |
| needsRefresh = false; |
| break; |
| } |
| } |
| |
| // Add the new model on the stack |
| if (needsRefresh) { |
| |
| // Clear off the old model instance |
| if (originalModel != null) { |
| root.remove(originalModel); |
| } |
| if (newModel != null) { |
| stack.push(newModel); |
| } |
| } |
| } |
| } |
| } |