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.TurbineServices;
26 import org.apache.turbine.util.RunData;
27 import org.apache.velocity.context.Context;
28
29 /**
30 * This is a Facade class for PullService.
31 *
32 * This class provides static methods that call related methods of the
33 * implementation of the PullService used by the System, according to
34 * the settings in TurbineResources.
35 *
36 * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
37 * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</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: TurbinePull.java 1706239 2015-10-01 13:18:35Z tv $
41 */
42 public abstract class TurbinePull
43 {
44 /**
45 * Utility method for accessing the service
46 * implementation
47 *
48 * @return a PullService implementation instance
49 */
50 public static PullService getService()
51 {
52 return (PullService) TurbineServices
53 .getInstance().getService(PullService.SERVICE_NAME);
54 }
55
56 /**
57 * Get the context containing global tools that will be
58 * use as part of the Turbine Pull Model.
59 *
60 * @return A Context object which contains the
61 * Global Tool instances.
62 */
63 public static final Context getGlobalContext()
64 {
65 return getService().getGlobalContext();
66 }
67
68 /**
69 * Checks whether this service has been registered. This is
70 * required by the TurbineVelocityService so it can determine
71 * whether to attempt to place the ToolBox in the context.
72 * <p>
73 * So users can use Turbine with templates in the traditional
74 * manner. If the Pull Service is not listed in
75 * <code>TurbineResources.props</code>, or no tools are specified
76 * the TurbineVelocityService will behave in its traditional
77 * manner.
78 * @return true if the service is registered within Turbine
79 */
80 public static final boolean isRegistered()
81 {
82 return TurbineServices.getInstance()
83 .isRegistered(PullService.SERVICE_NAME);
84 }
85
86 /**
87 * Return the absolute path of the resources directory
88 * used by application tools.
89 *
90 * @return A directory path in the file system or null.
91 */
92 public static final String getAbsolutePathToResourcesDirectory()
93 {
94 return getService().getAbsolutePathToResourcesDirectory();
95 }
96
97 /**
98 * Return the resources directory. This is relative
99 * to the webapp context.
100 *
101 * @return A directory path to the resources directory relative to the webapp root or null.
102 */
103 public static final String getResourcesDirectory()
104 {
105 return getService().getResourcesDirectory();
106 }
107
108 /**
109 * Populate the given context with all request, session
110 * and persistent scope tools (it is assumed that the context
111 * already wraps the global context, and thus already contains
112 * the global tools).
113 *
114 * @param context a Velocity Context to populate
115 * @param pipelineData a RunData object for request specific data
116 */
117 public static void populateContext(Context context, PipelineData pipelineData)
118 {
119 getService().populateContext(context, pipelineData);
120 }
121
122 /**
123 * Populate the given context with all request, session
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 public static void populateContext(Context context, RunData data)
132 {
133 getService().populateContext(context, data);
134 }
135
136 /**
137 * Release tool instances from the given context to the
138 * object pool
139 *
140 * @param context a Velocity Context to release tools from
141 */
142 public static void releaseTools(Context context)
143 {
144 getService().releaseTools(context);
145 }
146
147 /**
148 * Helper method that allows you to easily get a tool
149 * from a Context. Essentially, it just does the cast
150 * to an Application tool for you.
151 *
152 * @param context a Velocity Context to get tools from
153 * @param name the name of the tool to get
154 * @return ApplicationTool null if no tool could be found
155 */
156 public static ApplicationTool getTool(Context context,
157 String name)
158 {
159 try
160 {
161 return (ApplicationTool) context.get(name);
162 }
163 catch (Exception e)
164 {
165 // ignore
166 }
167 return null;
168 }
169 }