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