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 022import org.apache.commons.lang.StringUtils; 023import org.apache.commons.lang.exception.ExceptionUtils; 024import org.apache.turbine.TurbineConstants; 025import org.apache.turbine.pipeline.PipelineData; 026import org.apache.turbine.util.RunData; 027import org.apache.velocity.context.Context; 028 029/** 030 * VelocityCachedScreen is Turbine 2.3.3 VelocityDirectScreen (same package) 031 * with methods added for {@link PipelineData}. 032 * It is is a screen class which buffers its output 033 * before flushing the output stream. It is used in Jetspeed-1 portal. 034 * <p> 035 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a> 036 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> 037 * @version $Id$ 038 */ 039public class VelocityCachedScreen 040 extends VelocityScreen 041{ 042 /** The prefix for lookup up screen pages */ 043 private String prefix = getPrefix() + "/"; 044 045 /** 046 * This builds the Velocity template. 047 * 048 * @param pipelineData Turbine information. 049 * @return A ConcreteElement. 050 * @throws Exception a generic exception. 051 */ 052 @Override 053 public String buildTemplate(PipelineData pipelineData) 054 throws Exception 055 { 056 RunData data = getRunData(pipelineData); 057 Context context = velocity.getContext(pipelineData); 058 059 String screenTemplate = data.getTemplateInfo().getScreenTemplate(); 060 String templateName 061 = templateService.getScreenTemplateName(screenTemplate); 062 063 // The Template Service could not find the Screen 064 if (StringUtils.isEmpty(templateName)) 065 { 066 log.error("Screen " + screenTemplate + " not found!"); 067 throw new Exception("Could not find screen for " + screenTemplate); 068 } 069 070 try 071 { 072 velocity.handleRequest(context, prefix + templateName, data.getOut()); 073 } 074 catch (Exception e) 075 { 076 // If there is an error, build a $processingException and 077 // attempt to call the error.vm template in the screens 078 // directory. 079 context.put (TurbineConstants.PROCESSING_EXCEPTION_PLACEHOLDER, e.toString()); 080 context.put (TurbineConstants.STACK_TRACE_PLACEHOLDER, ExceptionUtils.getStackTrace(e)); 081 082 velocity.handleRequest(context, prefix + templateError, data.getOut()); 083 } 084 085 return null; 086 } 087} 088 089