    001package org.apache.turbine.modules.screens;
    002
    003/*
    004 * Licensed to the Apache Software Foundation (ASF) under one
    005 * or more contributor license agreements.  See the NOTICE file
    006 * distributed with this work for additional information
    007 * regarding copyright ownership.  The ASF licenses this file
    008 * to you under the Apache License, Version 2.0 (the
    009 * "License"); you may not use this file except in compliance
    010 * with the License.  You may obtain a copy of the License at
    011 *
    012 *   http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing,
    015 * software distributed under the License is distributed on an
    016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    017 * KIND, either express or implied.  See the License for the
    018 * specific language governing permissions and limitations
    019 * under the License.
    020 */
    021
    022
    023import org.apache.turbine.pipeline.PipelineData;
    024import org.apache.turbine.services.velocity.TurbineVelocity;
    025import org.apache.velocity.context.Context;
    026
    027/**
    028 * VelocitySecureScreen
    029 *
    030 * Always performs a Security Check that you've defined before
    031 * executing the doBuildTemplate().  You should extend this class and
    032 * add the specific security check needed.  If you have a number of
    033 * screens that need to perform the same check, you could make a base
    034 * screen by extending this class and implementing the isAuthorized().
    035 * Then each screen that needs to perform the same check could extend
    036 * your base screen.
    037 *
    038 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
    039 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    040 * @version $Id: VelocitySecureScreen.java 1706239 2015-10-01 13:18:35Z tv $
    041 */
    042public abstract class VelocitySecureScreen
    043        extends VelocityScreen
    044{
    045    /**
    046     * Implement this to add information to the context.
    047     *
    048     * @param pipelineData Turbine information.
    049     * @param context Context for web pages.
    050     * @exception Exception, a generic exception.
    051     */
    052    @Override
    053    protected abstract void doBuildTemplate(PipelineData pipelineData,
    054                                            Context context)
    055            throws Exception;
    056
    057    /**
    058     * This method overrides the method in VelocityScreen to
    059     * perform a security check first.
    060     *
    061     * @param pipelineData Turbine information.
    062     * @exception Exception, a generic exception.
    063     */
    064    @Override
    065    protected void doBuildTemplate(PipelineData pipelineData)
    066        throws Exception
    067    {
    068        if (isAuthorized(pipelineData))
    069        {
    070            doBuildTemplate(pipelineData, TurbineVelocity.getContext(pipelineData));
    071        }
    072    }
    073
    074    /**
    075     * Implement this method to perform the security check needed.
    076     * You should set the template in this method that you want the
    077     * user to be sent to if they're unauthorized.  See the
    078     * VelocitySecurityCheck utility.
    079     *
    080     * @param pipelineData Turbine information.
    081     * @return True if the user is authorized to access the screen.
    082     * @exception Exception, a generic exception.
    083     */
    084    protected abstract boolean isAuthorized(PipelineData pipelineData)
    085            throws Exception;
    086}