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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
    23  import org.apache.turbine.pipeline.PipelineData;
    24  import org.apache.velocity.context.Context;
    25
    26  /**
    27   * VelocitySecureScreen
    28   *
    29   * Always performs a Security Check that you've defined before
    30   * executing the doBuildTemplate().  You should extend this class and
    31   * add the specific security check needed.  If you have a number of
    32   * screens that need to perform the same check, you could make a base
    33   * screen by extending this class and implementing the isAuthorized().
    34   * Then each screen that needs to perform the same check could extend
    35   * your base screen.
    36   *
    37   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
    38   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    39   * @version $Id: VelocitySecureScreen.java 1773378 2016-12-09 13:19:59Z tv $
    40   */
    41  public abstract class VelocitySecureScreen
    42          extends VelocityScreen
    43  {
    44      /**
    45       * Implement this to add information to the context.
    46       *
    47       * @param pipelineData Turbine information.
    48       * @param context Context for web pages.
    49       * @throws Exception a generic exception.
    50       */
    51      @Override
    52      protected abstract void doBuildTemplate(PipelineData pipelineData,
    53                                              Context context)
    54              throws Exception;
    55
    56      /**
    57       * This method overrides the method in VelocityScreen to
    58       * perform a security check first.
    59       *
    60       * @param pipelineData Turbine information.
    61       * @throws Exception a generic exception.
    62       */
    63      @Override
    64      protected void doBuildTemplate(PipelineData pipelineData)
    65          throws Exception
    66      {
    67          if (isAuthorized(pipelineData))
    68          {
    69              doBuildTemplate(pipelineData, velocity.getContext(pipelineData));
    70          }
    71      }
    72
    73      /**
    74       * Implement this method to perform the security check needed.
    75       * You should set the template in this method that you want the
    76       * user to be sent to if they're unauthorized.  See the
    77       * VelocitySecurityCheck utility.
    78       *
    79       * @param pipelineData Turbine information.
    80       * @return True if the user is authorized to access the screen.
    81       * @throws Exception a generic exception.
    82       */
    83      protected abstract boolean isAuthorized(PipelineData pipelineData)
    84              throws Exception;
    85  }