1 package org.apache.turbine.modules.screens; 2 3 /* 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 22 import org.apache.turbine.pipeline.PipelineData; 23 24 /** 25 * An extension to JSONScreen that performs a Security Check before invoking 26 * doBuildTemplate(). You should extend this class and add the specific 27 * security check needed. If you have a number of screens that need to perform 28 * the same check, you could make a base screen by extending this class and 29 * implementing the isAuthorized(). Then each screen that needs to perform the 30 * same check could extend your base screen. 31 * 32 * <p>Typically you would extend this class and override the doOutput() method 33 * to use TurbineJsonRpc to register the POJOs that will provide the functions 34 * you are making available via JSON-RPC. Use JSONScreen if you <b>do not</b> 35 * need the user to be logged in prior to executing the functions you provide.</p> 36 * 37 * <p>Here is an example from a superclass: 38 * <code> 39 * public void doOutput(PipelineData data) throws Exception 40 * { 41 * User user = data.getUser(); 42 * 43 * MySecureJsonFunctions myFunctions 44 * = new MySecureJsonFunctions(user.getName()); 45 * 46 * // Session specific 47 * TurbineJsonRpc.registerObject(data.getSession(), "myFunctions", myFunctions); 48 * 49 * // Global 50 * //TurbineJsonRpc.registerObjectGlobal("testGlobal", testObject); 51 * 52 * super.doOutput(data); 53 * } 54 * </code></p> 55 * 56 * <p>The class MyFunctions would be something like: 57 * <code> 58 * public class MySecureJsonFunctions 59 * { 60 * private final String name; 61 * 62 * public MySecureJsonFunctions(String name) 63 * { 64 * this.name = name; 65 * } 66 * 67 * private String getName(String clientParameter) 68 * { 69 * return "Client " + clientParameter + " says Hello World to " + name; 70 * } 71 * } 72 * </code></p> 73 * 74 * @author <a href="mailto:seade@policypoint.net">Scott Eade</a> 75 * @version $Id$ 76 */ 77 public abstract class JSONSecureScreen extends JSONScreen 78 { 79 /** 80 * This method overrides the method in JSONScreen to perform a security 81 * check prior to producing the output. 82 * 83 * @param pipelineData Turbine information. 84 * @throws Exception a generic exception. 85 */ 86 @Override 87 protected void doOutput(PipelineData pipelineData) throws Exception 88 { 89 if (isAuthorized(pipelineData)) 90 { 91 super.doOutput(pipelineData); 92 } 93 } 94 95 /** 96 * Override this method to perform the necessary security checks. 97 * 98 * @param pipelineData Turbine information. 99 * @return <code>true</code> if the user is authorized to access the screen. 100 * @throws Exception A generic exception. 101 */ 102 protected abstract boolean isAuthorized(PipelineData pipelineData) 103 throws Exception; 104 }