1 package org.apache.turbine.modules.screens;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import org.apache.commons.lang.StringUtils;
23 import org.apache.commons.lang.exception.ExceptionUtils;
24 import org.apache.turbine.TurbineConstants;
25 import org.apache.turbine.pipeline.PipelineData;
26 import org.apache.turbine.util.RunData;
27 import org.apache.velocity.context.Context;
28
29 /**
30 * VelocityCachedScreen is Turbine 2.3.3 VelocityDirectScreen (same package)
31 * with methods added for {@link PipelineData}.
32 * It is is a screen class which buffers its output
33 * before flushing the output stream. It is used in Jetspeed-1 portal.
34 * <p>
35 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
36 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
37 * @version $Id$
38 */
39 public class VelocityCachedScreen
40 extends VelocityScreen
41 {
42 /** The prefix for lookup up screen pages */
43 private String prefix = getPrefix() + "/";
44
45 /**
46 * This builds the Velocity template.
47 *
48 * @param pipelineData Turbine information.
49 * @return A ConcreteElement.
50 * @throws Exception a generic exception.
51 */
52 @Override
53 public String buildTemplate(PipelineData pipelineData)
54 throws Exception
55 {
56 RunData data = getRunData(pipelineData);
57 Context context = velocity.getContext(pipelineData);
58
59 String screenTemplate = data.getTemplateInfo().getScreenTemplate();
60 String templateName
61 = templateService.getScreenTemplateName(screenTemplate);
62
63 // The Template Service could not find the Screen
64 if (StringUtils.isEmpty(templateName))
65 {
66 log.error("Screen " + screenTemplate + " not found!");
67 throw new Exception("Could not find screen for " + screenTemplate);
68 }
69
70 try
71 {
72 velocity.handleRequest(context, prefix + templateName, data.getOut());
73 }
74 catch (Exception e)
75 {
76 // If there is an error, build a $processingException and
77 // attempt to call the error.vm template in the screens
78 // directory.
79 context.put (TurbineConstants.PROCESSING_EXCEPTION_PLACEHOLDER, e.toString());
80 context.put (TurbineConstants.STACK_TRACE_PLACEHOLDER, ExceptionUtils.getStackTrace(e));
81
82 velocity.handleRequest(context, prefix + templateError, data.getOut());
83 }
84
85 return null;
86 }
87 }
88
89