001 package org.apache.turbine.services.pull;
002
003
004 /*
005 * Licensed to the Apache Software Foundation (ASF) under one
006 * or more contributor license agreements. See the NOTICE file
007 * distributed with this work for additional information
008 * regarding copyright ownership. The ASF licenses this file
009 * to you under the Apache License, Version 2.0 (the
010 * "License"); you may not use this file except in compliance
011 * with the License. You may obtain a copy of the License at
012 *
013 * http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing,
016 * software distributed under the License is distributed on an
017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
018 * KIND, either express or implied. See the License for the
019 * specific language governing permissions and limitations
020 * under the License.
021 */
022
023
024 import org.apache.turbine.pipeline.PipelineData;
025 import org.apache.turbine.services.Service;
026 import org.apache.turbine.util.RunData;
027 import org.apache.velocity.context.Context;
028
029 /**
030 * The Pull Service manages the creation of application
031 * tools that are available to all templates in a
032 * Turbine application. By using the Pull Service you
033 * can avoid having to make Screens to populate a
034 * context for use in a particular template. The Pull
035 * Service creates a set of tools, as specified in
036 * the TR.props file.
037 *
038 * These tools can have global scope, request scope,
039 * authorized or session scope (i.e. stored in user temp hashmap)
040 * or persistent scope (i.e. stored in user perm hashmap)
041 *
042 * The standard way of referencing these global
043 * tools is through the toolbox handle. This handle
044 * is typically $toolbox, but can be specified in the
045 * TR.props file.
046 *
047 * So, for example, if you had a UI Manager tool
048 * which created a set of UI attributes from a
049 * properties file, and one of the properties
050 * was 'bgcolor', then you could access this
051 * UI attribute with $ui.bgcolor. The identifier
052 * that is given to the tool, in this case 'ui', can
053 * be specified as well.
054 *
055 * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
056 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
057 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
058 * @version $Id: PullService.java 957284 2010-06-23 17:53:31Z tv $
059 */
060 public interface PullService
061 extends Service
062 {
063 /** The key under which this service is stored in TurbineServices. */
064 String SERVICE_NAME = "PullService";
065
066 /** Property Key for the global tools */
067 String GLOBAL_TOOL = "tool.global";
068
069 /** Property Key for the request tools */
070 String REQUEST_TOOL = "tool.request";
071
072 /** Property Key for the session tools */
073 String SESSION_TOOL = "tool.session";
074
075 /** Property Key for the authorized tools */
076 String AUTHORIZED_TOOL = "tool.authorized";
077
078 /** Property Key for the persistent tools */
079 String PERSISTENT_TOOL = "tool.persistent";
080
081 /** Property tag for application tool resources directory */
082 String TOOL_RESOURCES_DIR_KEY = "tools.resources.dir";
083
084 /**
085 * Default value for the application tool resources. This is relative
086 * to the webapp root
087 */
088 String TOOL_RESOURCES_DIR_DEFAULT = "resources";
089
090 /**
091 * Property tag for per request tool refreshing (for obvious reasons
092 * has no effect for per-request tools)
093 */
094 String TOOLS_PER_REQUEST_REFRESH_KEY = "tools.per.request.refresh";
095
096 /** Default value for per request tool refreshing */
097 boolean TOOLS_PER_REQUEST_REFRESH_DEFAULT = false;
098
099 /** 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 data 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 }