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.lang3.StringUtils;
23 import org.apache.commons.lang3.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 * VelocityDirectScreen is a screen class which returns its output
31 * directly to the output stream. It can be used if buffering an
32 * output screen isn't possible or the result doesn't fit in the
33 * memory.
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 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
38 * @version $Id$
39 */
40 public class VelocityDirectScreen
41 extends VelocityScreen
42 {
43 /**
44 * This builds the Velocity template.
45 *
46 * @param pipelineData Turbine information.
47 * @return the content of the screen
48 * @throws Exception a generic exception.
49 */
50 @Override
51 public String buildTemplate(PipelineData pipelineData)
52 throws Exception
53 {
54 RunData data = pipelineData.getRunData();
55 Context context = velocity.getContext(pipelineData);
56
57 String screenTemplate = data.getTemplateInfo().getScreenTemplate();
58 String templateName
59 = templateService.getScreenTemplateName(screenTemplate);
60
61 // The Template Service could not find the Screen
62 if (StringUtils.isEmpty(templateName))
63 {
64 log.error("Screen " + screenTemplate + " not found!");
65 throw new Exception("Could not find screen for " + screenTemplate);
66 }
67
68 try
69 {
70 velocity.handleRequest(context,
71 prefix + templateName,
72 data.getResponse().getOutputStream());
73
74 }
75 catch (Exception e)
76 {
77 // If there is an error, build a $processingException and
78 // attempt to call the error.vm template in the screens
79 // directory.
80 context.put (TurbineConstants.PROCESSING_EXCEPTION_PLACEHOLDER, e.toString());
81 context.put (TurbineConstants.STACK_TRACE_PLACEHOLDER, ExceptionUtils.getStackTrace(e));
82
83 velocity.handleRequest(context, prefix + templateError,
84 data.getResponse().getOutputStream());
85 }
86
87 return null;
88 }
89 }