1 package org.apache.turbine.services.velocity;
2
3
4 /*
5 * Licensed to the Apache Software Foundation (ASF) under one
6 * or more contributor license agreements. See the NOTICE file
7 * distributed with this work for additional information
8 * regarding copyright ownership. The ASF licenses this file
9 * to you under the Apache License, Version 2.0 (the
10 * "License"); you may not use this file except in compliance
11 * with the License. You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing,
16 * software distributed under the License is distributed on an
17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18 * KIND, either express or implied. See the License for the
19 * specific language governing permissions and limitations
20 * under the License.
21 */
22
23
24 import java.io.OutputStream;
25 import java.io.Writer;
26
27 import org.apache.turbine.pipeline.PipelineData;
28 import org.apache.turbine.services.Service;
29 import org.apache.turbine.util.TurbineException;
30 import org.apache.velocity.context.Context;
31
32 /**
33 * Implementations of the VelocityService interface.
34 *
35 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
36 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
37 * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
38 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
39 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
40 * @version $Id$
41 */
42 public interface VelocityService
43 extends Service
44 {
45 /** The Service Name */
46 String SERVICE_NAME = "VelocityService";
47
48 /** Key for storing the Context in the RunData object */
49 String CONTEXT = "VELOCITY_CONTEXT";
50
51 /** The default extension of Velocity Pages */
52 String VELOCITY_EXTENSION = "vm";
53
54 /** The Key for storing the RunData Object in the Context */
55 String RUNDATA_KEY = "data";
56
57 /** The Key for storing the PipelineData Object in the Context */
58 String PIPELINEDATA_KEY = "pipelineData";
59
60 /** Shall we catch Velocity Errors and report them? */
61 String CATCH_ERRORS_KEY = "catch.errors";
62
63 /** Default: Yes */
64 boolean CATCH_ERRORS_DEFAULT = true;
65
66 /**
67 * Process the request and fill in the template with the values
68 * you set in the Context.
69 *
70 * @param context A Context.
71 * @param template A String with the filename of the template.
72 * @return The process template as a String.
73 * @throws Exception a generic exception.
74 */
75 String handleRequest(Context context, String template)
76 throws Exception;
77
78 /**
79 * Process the request and fill in the template with the values
80 * you set in the Context.
81 *
82 * @param context A Context.
83 * @param filename A String with the filename of the template.
84 * @param out A OutputStream where we will write the process template as
85 * a String.
86 * @throws TurbineException Any exception thrown while processing will be
87 * wrapped into a TurbineException and rethrown.
88 */
89 void handleRequest(Context context, String filename, OutputStream out)
90 throws TurbineException;
91
92 /**
93 * Process the request and fill in the template with the values
94 * you set in the Context.
95 *
96 * @param context A Context.
97 * @param filename A String with the filename of the template.
98 * @param writer A Writer where we will write the process template as
99 * a String.
100 * @throws TurbineException Any exception thrown while processing will be
101 * wrapped into a TurbineException and rethrown.
102 */
103 void handleRequest(Context context, String filename, Writer writer)
104 throws TurbineException;
105
106 /**
107 * Create an empty WebContext object.
108 *
109 * @return An empty WebContext object.
110 */
111 Context getContext();
112
113 /**
114 * This method returns a new, empty Context object.
115 *
116 * @return A WebContext.
117 */
118 Context getNewContext();
119
120 /**
121 * Create a Context from the PipelineData object. Adds a pointer to
122 * the PipelineData object to the Context so that PipelineData is available in
123 * the templates.
124 *
125 * @param pipelineData The Turbine PipelineData object.
126 * @return A clone of the Context needed by Velocity.
127 */
128 Context getContext(PipelineData pipelineData);
129
130 /**
131 * Performs post-request actions (releases context
132 * tools back to the object pool).
133 *
134 * @param context a Velocity Context
135 */
136 void requestFinished(Context context);
137 }