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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.RunData;
30  import org.apache.turbine.util.TurbineException;
31  
32  import org.apache.velocity.context.Context;
33  
34  /**
35   * Implementations of the VelocityService interface.
36   *
37   * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
38   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
39   * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
40   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
41   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
42   * @version $Id: VelocityService.java 615328 2008-01-25 20:25:05Z tv $
43   */
44  public interface VelocityService
45          extends Service
46  {
47      /** The Service Name */
48      String SERVICE_NAME = "VelocityService";
49  
50      /** Key for storing the Context in the RunData object */
51      String CONTEXT = "VELOCITY_CONTEXT";
52  
53      /** The default extension of Velocity Pages */
54      String VELOCITY_EXTENSION = "vm";
55  
56      /** The Key for storing the RunData Object in the Context */
57      String RUNDATA_KEY = "data";
58  
59      /** The Key for storing the PipelineData Object in the Context */
60      String PIPELINEDATA_KEY = "pipelineData";
61  
62      /** Shall we catch Velocity Errors and report them? */
63      String CATCH_ERRORS_KEY = "catch.errors";
64  
65      /** Default: Yes */
66      boolean CATCH_ERRORS_DEFAULT = true;
67  
68      /**
69       * Process the request and fill in the template with the values
70       * you set in the Context.
71       *
72       * @param context A Context.
73       * @param template A String with the filename of the template.
74       * @return The process template as a String.
75       * @exception Exception a generic exception.
76       */
77      String handleRequest(Context context, String template)
78              throws Exception;
79  
80      /**
81       * Process the request and fill in the template with the values
82       * you set in the Context.
83       *
84       * @param context A Context.
85       * @param filename A String with the filename of the template.
86       * @param out A OutputStream where we will write the process template as
87       *        a String.
88       * @throws TurbineException Any exception trown while processing will be
89       *         wrapped into a TurbineException and rethrown.
90       */
91      void handleRequest(Context context, String filename, OutputStream out)
92              throws TurbineException;
93  
94      /**
95       * Process the request and fill in the template with the values
96       * you set in the Context.
97       *
98       * @param context A Context.
99       * @param filename A String with the filename of the template.
100      * @param writer A Writer where we will write the process template as
101      *        a String.
102      * @throws TurbineException Any exception trown while processing will be
103      *         wrapped into a TurbineException and rethrown.
104      */
105     void handleRequest(Context context, String filename, Writer writer)
106             throws TurbineException;
107 
108     /**
109      * Create an empty WebContext object.
110      *
111      * @return An empty WebContext object.
112      */
113     Context getContext();
114 
115     /**
116      * This method returns a new, empty Context object.
117      *
118      * @return A WebContext.
119      */
120     Context getNewContext();
121 
122     /**
123      * Create a Context from the RunData object.  Adds a pointer to
124      * the RunData object to the Context so that RunData is available in
125      * the templates.
126      *
127      * @param data The Turbine RunData object.
128      * @return A clone of the Context needed by Velocity.
129      */
130     Context getContext(RunData data);
131 
132     /**
133      * Create a Context from the RunData object.  Adds a pointer to
134      * the RunData object to the Context so that RunData is available in
135      * the templates.
136      *
137      * @param data The Turbine RunData object.
138      * @return A clone of the Context needed by Velocity.
139      */
140     Context getContext(PipelineData pipelineData);
141 
142 
143 
144     /**
145      * Performs post-request actions (releases context
146      * tools back to the object pool).
147      *
148      * @param context a Velocity Context
149      */
150     void requestFinished(Context context);
151 }