001package org.apache.turbine.pipeline;
002
003
004/*
005 * Licensed to the Apache Software Foundation (ASF) under one
006 * or more contributor license agreements.  See the NOTICE file
007 * distributed with this work for additional information
008 * regarding copyright ownership.  The ASF licenses this file
009 * to you under the Apache License, Version 2.0 (the
010 * "License"); you may not use this file except in compliance
011 * with the License.  You may obtain a copy of the License at
012 *
013 *   http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing,
016 * software distributed under the License is distributed on an
017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
018 * KIND, either express or implied.  See the License for the
019 * specific language governing permissions and limitations
020 * under the License.
021 */
022
023
024import java.io.IOException;
025
026import org.apache.commons.logging.Log;
027import org.apache.commons.logging.LogFactory;
028import org.apache.turbine.util.RunData;
029import org.apache.turbine.util.TurbineException;
030import org.apache.turbine.util.uri.URIConstants;
031
032/**
033 * This valve is responsible for setting the 'target' property of the RunData.
034 * If it is not already set it attempts to get the target from the request
035 * parameter 'template'. If the parameter is not set, we use the homepage
036 * specified by the configuration property Turbine.TEMPLATE_HOMEPAGE.
037 *
038 * FIXME: The request parameter which determines the template should be
039 *        configurable.
040 *
041 * @author <a href="mailto:james@jamestaylor.org">James Taylor</a>
042 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
043 */
044public class DetermineTargetValve
045    extends AbstractValve
046{
047    private static final Log log
048        = LogFactory.getLog(DetermineTargetValve.class);
049
050    /**
051     * @see org.apache.turbine.pipeline.Valve#invoke(PipelineData, ValveContext)
052     */
053    public void invoke(PipelineData pipelineData, ValveContext context)
054        throws IOException, TurbineException
055    {
056        RunData runData = getRunData(pipelineData);
057        if (! runData.hasScreen())
058        {
059            String target = runData.getParameters().getString(URIConstants.CGI_SCREEN_PARAM);
060
061            if (target != null)
062            {
063                runData.setScreen(target);
064
065                log.debug("Set screen target from request parameter");
066            }
067            else
068            {
069            /*    data.setScreen(Turbine.getConfiguration().getString(
070                    Turbine.TEMPLATE_HOMEPAGE));
071
072                log.debug("Set target using default value");
073                */
074                                log.debug("No target screen");
075            }
076
077        }
078
079        if (log.isDebugEnabled())
080        {
081            log.debug("Screen Target is now: " + runData.getScreen());
082        }
083
084        // Pass control to the next Valve in the Pipeline
085        context.invokeNext(pipelineData);
086    }
087}