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1   package org.apache.turbine.services.pull;
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.turbine.services.Service;
23  import org.apache.turbine.util.RunData;
24  import org.apache.velocity.context.Context;
25  
26  /***
27   * The Pull Service manages the creation of application
28   * tools that are available to all templates in a
29   * Turbine application. By using the Pull Service you
30   * can avoid having to make Screens to populate a
31   * context for use in a particular template. The Pull
32   * Service creates a set of tools, as specified in
33   * the TR.props file.
34   *
35   * These tools can have global scope, request scope,
36   * authorized or session scope (i.e. stored in user temp hashmap)
37   * or persistent scope (i.e. stored in user perm hashmap)
38   *
39   * The standard way of referencing these global
40   * tools is through the toolbox handle. This handle
41   * is typically $toolbox, but can be specified in the
42   * TR.props file.
43   *
44   * So, for example, if you had a UI Manager tool
45   * which created a set of UI attributes from a
46   * properties file, and one of the properties
47   * was 'bgcolor', then you could access this
48   * UI attribute with $ui.bgcolor. The identifier
49   * that is given to the tool, in this case 'ui', can
50   * be specified as well.
51   *
52   * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
53   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
54   * @version $Id: PullService.java 534527 2007-05-02 16:10:59Z tv $
55   */
56  public interface PullService
57          extends Service
58  {
59      /*** The key under which this service is stored in TurbineServices. */
60      String SERVICE_NAME = "PullService";
61  
62      /*** Property Key for the global tools */
63      String GLOBAL_TOOL = "tool.global";
64  
65      /*** Property Key for the request tools */
66      String REQUEST_TOOL = "tool.request";
67  
68      /*** Property Key for the session tools */
69      String SESSION_TOOL = "tool.session";
70  
71      /*** Property Key for the authorized tools */
72      String AUTHORIZED_TOOL = "tool.authorized";
73  
74      /*** Property Key for the persistent tools */
75      String PERSISTENT_TOOL = "tool.persistent";
76  
77      /*** Property tag for application tool resources directory */
78      String TOOL_RESOURCES_DIR_KEY = "tools.resources.dir";
79  
80      /***
81       * Default value for the application tool resources. This is relative
82       * to the webapp root
83       */
84      String TOOL_RESOURCES_DIR_DEFAULT = "resources";
85  
86      /***
87       * Property tag for per request tool refreshing (for obvious reasons
88       * has no effect for per-request tools)
89       */
90      String TOOLS_PER_REQUEST_REFRESH_KEY = "tools.per.request.refresh";
91  
92      /*** Default value for per request tool refreshing */
93      boolean TOOLS_PER_REQUEST_REFRESH_DEFAULT = false;
94  
95      /*** prefix for key used in the session to store session scope pull tools */
96      String SESSION_TOOLS_ATTRIBUTE_PREFIX = "turbine.sessiontools.";
97  
98      /***
99       * Get the context containing global tools that will be
100      * use as part of the Turbine Pull Model.
101      *
102      * @return A Context object which contains the
103      *         Global Tool instances.
104      */
105     Context getGlobalContext();
106 
107     /***
108      * Populate the given context with all request, session, authorized
109      * and persistent scope tools (it is assumed that the context
110      * already wraps the global context, and thus already contains
111      * the global tools).
112      *
113      * @param context a Velocity Context to populate
114      * @param data a RunData object for request specific data
115      */
116     void populateContext(Context context, RunData data);
117 
118     /***
119      * Return the absolute path of the resources directory
120      * used by application tools.
121      *
122      * @return A directory path in the file system or null.
123      */
124     String getAbsolutePathToResourcesDirectory();
125 
126     /***
127      * Return the resources directory. This is relative
128      * to the webapp context.
129      *
130      * @return A directory path to the resources directory relative to the webapp root or null.
131      */
132     String getResourcesDirectory();
133 
134     /***
135      * Refresh the global tools .
136      * @deprecated No longer needed as Pull and Velocity Service are now more separate.
137      */
138     void refreshGlobalTools();
139 
140     /***
141      * Shoud we refresh the tools
142      * on each request. For development purposes.
143      *
144      * @return true if we should refresh the tools on every request.
145      * @deprecated No longer needed as Pull and Velocity Service are now more separate.
146      */
147     boolean refreshToolsPerRequest();
148 
149     /***
150      * Release tool instances from the given context to the
151      * object pool
152      *
153      * @param context a Velocity Context to release tools from
154      */
155     void releaseTools(Context context);
156 }