001    package 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    import org.apache.commons.lang.StringUtils;
023    import org.apache.commons.lang.exception.ExceptionUtils;
024    import org.apache.ecs.ConcreteElement;
025    import org.apache.turbine.Turbine;
026    import org.apache.turbine.TurbineConstants;
027    import org.apache.turbine.pipeline.PipelineData;
028    import org.apache.turbine.services.template.TurbineTemplate;
029    import org.apache.turbine.services.velocity.TurbineVelocity;
030    import org.apache.turbine.util.RunData;
031    import org.apache.velocity.context.Context;
032    
033    /**
034     * VelocityDirectScreen is a screen class which returns its output
035     * directly to the output stream. It can be used if buffering an
036     * output screen isn't possible or the result doesn't fit in the
037     * memory.
038     * <p>
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: VelocityDirectScreen.java 938645 2010-04-27 20:57:51Z tv $
043     */
044    public class VelocityDirectScreen
045        extends VelocityScreen
046    {
047        /** The prefix for lookup up screen pages */
048        private String prefix = getPrefix() + "/";
049    
050        /**
051         * This builds the Velocity template.
052         *
053         * @deprecated Use PipelineData version instead.
054         * @param data Turbine information.
055         * @return A ConcreteElement.
056         * @exception Exception, a generic exception.
057         */
058        public ConcreteElement buildTemplate(RunData data)
059            throws Exception
060        {
061            Context context = TurbineVelocity.getContext(data);
062    
063            String screenTemplate = data.getTemplateInfo().getScreenTemplate();
064            String templateName
065                = TurbineTemplate.getScreenTemplateName(screenTemplate);
066    
067            // The Template Service could not find the Screen
068            if (StringUtils.isEmpty(templateName))
069            {
070                log.error("Screen " + screenTemplate + " not found!");
071                throw new Exception("Could not find screen for " + screenTemplate);
072            }
073    
074            try
075            {
076                TurbineVelocity.handleRequest(context,
077                                              prefix + templateName,
078                                              data.getResponse().getOutputStream());
079    
080            }
081            catch (Exception e)
082            {
083                // If there is an error, build a $processingException and
084                // attempt to call the error.vm template in the screens
085                // directory.
086                context.put (TurbineConstants.PROCESSING_EXCEPTION_PLACEHOLDER, e.toString());
087                context.put (TurbineConstants.STACK_TRACE_PLACEHOLDER, ExceptionUtils.getStackTrace(e));
088    
089                templateName = Turbine.getConfiguration()
090                    .getString(TurbineConstants.TEMPLATE_ERROR_KEY,
091                               TurbineConstants.TEMPLATE_ERROR_VM);
092    
093                TurbineVelocity.handleRequest(context,
094                        prefix + templateName,
095                        data.getResponse().getOutputStream());
096            }
097    
098            return null;
099        }
100    
101        /**
102         * This builds the Velocity template.
103         *
104         * @param data Turbine information.
105         * @return A ConcreteElement.
106         * @exception Exception, a generic exception.
107         */
108        public ConcreteElement buildTemplate(PipelineData pipelineData)
109            throws Exception
110        {
111            RunData data = getRunData(pipelineData);
112            Context context = TurbineVelocity.getContext(pipelineData);
113    
114            String screenTemplate = data.getTemplateInfo().getScreenTemplate();
115            String templateName
116                = TurbineTemplate.getScreenTemplateName(screenTemplate);
117    
118            // The Template Service could not find the Screen
119            if (StringUtils.isEmpty(templateName))
120            {
121                log.error("Screen " + screenTemplate + " not found!");
122                throw new Exception("Could not find screen for " + screenTemplate);
123            }
124    
125            try
126            {
127                TurbineVelocity.handleRequest(context,
128                                              prefix + templateName,
129                                              data.getResponse().getOutputStream());
130    
131            }
132            catch (Exception e)
133            {
134                // If there is an error, build a $processingException and
135                // attempt to call the error.vm template in the screens
136                // directory.
137                context.put (TurbineConstants.PROCESSING_EXCEPTION_PLACEHOLDER, e.toString());
138                context.put (TurbineConstants.STACK_TRACE_PLACEHOLDER, ExceptionUtils.getStackTrace(e));
139    
140                templateName = Turbine.getConfiguration()
141                    .getString(TurbineConstants.TEMPLATE_ERROR_KEY,
142                               TurbineConstants.TEMPLATE_ERROR_VM);
143    
144                TurbineVelocity.handleRequest(context,
145                        prefix + templateName,
146                        data.getResponse().getOutputStream());
147            }
148    
149            return null;
150        }
151    }