001package org.apache.turbine.modules.navigations;
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 org.apache.turbine.annotation.TurbineService;
025import org.apache.turbine.pipeline.PipelineData;
026import org.apache.turbine.services.template.TemplateService;
027import org.apache.turbine.services.velocity.VelocityService;
028import org.apache.turbine.util.RunData;
029import org.apache.velocity.context.Context;
030
031/**
032 * VelocityNavigation.  This screen relies on the VelocityPage
033 * being set as the default page.  The doBuildTemplate() assumes the
034 * user has put the template filename in the RunData parameter and set
035 * it to the value of the template file to execute.  Specialized
036 * Navigations screens should extend this class and override the
037 * doBuildTemplate( data , context) method.
038 *
039 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
040 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
041 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
042 * @version $Id$
043 */
044public class VelocityNavigation
045        extends TemplateNavigation
046{
047    /** The prefix for lookup up navigation pages */
048    private static final String prefix = PREFIX + "/";
049
050    /** Injected service instance */
051    @TurbineService
052    private VelocityService velocity;
053
054    /** Injected service instance */
055    @TurbineService
056    private TemplateService templateService;
057
058    /**
059     * Velocity Navigations extending this class should override this
060     * method to perform any particular business logic and add
061     * information to the context.
062     *
063     * @param pipelineData Turbine information.
064     * @param context Context for web pages.
065     * @throws Exception a generic exception.
066     */
067    protected void doBuildTemplate(PipelineData pipelineData,
068                                   Context context)
069            throws Exception
070    {
071        // empty
072    }
073
074    /**
075     * Needs to be implemented to make TemplateNavigation like us.
076     * The actual method that you should override is the one with the
077     * context in the parameter list.
078     *
079     * @param pipelineData Turbine information.
080     * @throws Exception a generic exception.
081     */
082    @Override
083    protected void doBuildTemplate(PipelineData pipelineData)
084            throws Exception
085    {
086        doBuildTemplate(pipelineData, velocity.getContext(pipelineData));
087    }
088
089    /**
090     * This builds the Velocity template.
091     *
092     * @param pipelineData Turbine information.
093     * @return the content of the navigation module
094     * @throws Exception a generic exception.
095     */
096    @Override
097    public String buildTemplate(PipelineData pipelineData)
098            throws Exception
099    {
100        RunData data = pipelineData.getRunData();
101        Context context = velocity.getContext(pipelineData);
102
103        String navigationTemplate = data.getTemplateInfo().getNavigationTemplate();
104        String templateName
105                = templateService.getNavigationTemplateName(navigationTemplate);
106
107        return velocity.handleRequest(context, prefix + templateName);
108    }
109}