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    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  import org.apache.turbine.util.RunData;
    24
    25  /**
    26   * An extension to JSONScreen that performs a Security Check before invoking
    27   * doBuildTemplate().  You should extend this class and add the specific
    28   * security check needed.  If you have a number of screens that need to perform
    29   * the same check, you could make a base screen by extending this class and
    30   * implementing the isAuthorized().  Then each screen that needs to perform the
    31   * same check could extend your base screen.
    32   *
    33   * <p>Typically you would extend this class and override the doOutput() method
    34   * to use TurbineJsonRpc to register the POJOs that will provide the functions
    35   * you are making available via JSON-RPC.  Use JSONScreen if you <p>do not</b>
    36   * need the user to be logged in prior to executing the functions you provide.
    37   *
    38   * <p>Here is an example from a superclass:
    39   * <code>
    40   * public void doOutput(RunData data) throws Exception
    41   * {
    42   *     User user = data.getUser();
    43   *
    44   *     MySecureJsonFunctions myFunctions
    45   *             = new MySecureJsonFunctions(user.getName());
    46   *
    47   *     // Session specific
    48   *     TurbineJsonRpc.registerObject(data.getSession(), "myFunctions", myFunctions);
    49   *
    50   *     // Global
    51   *     //TurbineJsonRpc.registerObjectGlobal("testGlobal", testObject);
    52   *
    53   *     super.doOutput(data);
    54   * }
    55   * </code>
    56   *
    57   * <p>The class MyFunctions would be something like:
    58   * <code>
    59   * public class MySecureJsonFunctions
    60   * {
    61   *     private final String name;
    62   *
    63   *     public MySecureJsonFunctions(String name)
    64   *     {
    65   *         this.name = name;
    66   *     }
    67   *
    68   *     private String getName(String clientParameter)
    69   *     {
    70   *         return "Client " + clientParameter + " says Hello World to " + name;
    71   *     }
    72   * }
    73   * </code>
    74   *
    75   * @author <a href="mailto:seade@policypoint.net">Scott Eade</a>
    76   * @version $Id: JSONSecureScreen.java 958672 2010-06-28 18:42:04Z tv $
    77   */
    78  public abstract class JSONSecureScreen extends JSONScreen
    79  {
    80      /**
    81       * This method overrides the method in JSONScreen to perform a security
    82       * check prior to producing the output.
    83       *
    84       * @param data Turbine information.
    85       * @exception Exception, a generic exception.
    86       * @deprecated Use PipelineData version instead.
    87       */
    88      protected void doOutput(RunData data) throws Exception
    89      {
    90          if (isAuthorized(data))
    91          {
    92              super.doOutput(data);
    93          }
    94      }
    95
    96      /**
    97       * Override this method to perform the necessary security checks.
    98       *
    99       * @param data Turbine information.
    100      * @return <code>true</code> if the user is authorized to access the screen.
    101      * @exception Exception A generic exception.
    102      * @deprecated Use PipelineData version instead.
    103      */
    104     protected abstract boolean isAuthorized(RunData data)
    105             throws Exception;
    106
    107     /**
    108      * This method overrides the method in JSONScreen to perform a security
    109      * check prior to producing the output.
    110      *
    111      * @param pipelineData Turbine information.
    112      * @exception Exception, a generic exception.
    113      */
    114     protected void doOutput(PipelineData pipelineData) throws Exception
    115     {
    116         if (isAuthorized(pipelineData))
    117         {
    118             super.doOutput(pipelineData);
    119         }
    120     }
    121
    122     /**
    123      * Override this method to perform the necessary security checks.
    124      *
    125      * @param pipelineData Turbine information.
    126      * @return <code>true</code> if the user is authorized to access the screen.
    127      * @exception Exception A generic exception.
    128      */
    129     protected abstract boolean isAuthorized(PipelineData pipelineData)
    130             throws Exception;
    131 }