package org.apache.turbine.modules.screens;

 /*

  * 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.

  */

 import org.apache.turbine.pipeline.PipelineData;

 /**

  * An extension to JSONScreen that performs a Security Check before invoking

  * doBuildTemplate().  You should extend this class and add the specific

  * security check needed.  If you have a number of screens that need to perform

  * the same check, you could make a base screen by extending this class and

  * implementing the isAuthorized().  Then each screen that needs to perform the

  * same check could extend your base screen.

  *

  * <p>Typically you would extend this class and override the doOutput() method

  * to use TurbineJsonRpc to register the POJOs that will provide the functions

  * you are making available via JSON-RPC.  Use JSONScreen if you <b>do not</b>

  * need the user to be logged in prior to executing the functions you provide.</p>

  *

  * <p>Here is an example from a superclass:

  * <code>

  * public void doOutput(PipelineData data) throws Exception

  * {

  *     User user = data.getUser();

  *

  *     MySecureJsonFunctions myFunctions

  *             = new MySecureJsonFunctions(user.getName());

  *

  *     // Session specific

  *     TurbineJsonRpc.registerObject(data.getSession(), "myFunctions", myFunctions);

  *

  *     // Global

  *     //TurbineJsonRpc.registerObjectGlobal("testGlobal", testObject);

  *

  *     super.doOutput(data);

  * }

  * </code></p>

  *

  * <p>The class MyFunctions would be something like:

  * <code>

  * public class MySecureJsonFunctions

  * {

  *     private final String name;

  *

  *     public MySecureJsonFunctions(String name)

  *     {

  *         this.name = name;

  *     }

  *

  *     private String getName(String clientParameter)

  *     {

  *         return "Client " + clientParameter + " says Hello World to " + name;

  *     }

  * }

  * </code></p>

  *

  * @author <a href="mailto:seade@policypoint.net">Scott Eade</a>

  * @version $Id: JSONSecureScreen.java 1773378 2016-12-09 13:19:59Z tv $

  */

 public abstract class JSONSecureScreen extends JSONScreen

 {

     /**

      * This method overrides the method in JSONScreen to perform a security

      * check prior to producing the output.

      *

      * @param pipelineData Turbine information.

      * @throws Exception a generic exception.

      */

     @Override

     protected void doOutput(PipelineData pipelineData) throws Exception

     {

         if (isAuthorized(pipelineData))

         {

             super.doOutput(pipelineData);

         }

     }

     /**

      * Override this method to perform the necessary security checks.

      *

      * @param pipelineData Turbine information.

      * @return <code>true</code> if the user is authorized to access the screen.

      * @throws Exception A generic exception.

      */

     protected abstract boolean isAuthorized(PipelineData pipelineData)

             throws Exception;

 }