| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 2 | <html><head> |
| 3 | |
| 4 | |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 5 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 6 | <title>Apache Felix - Extender Pattern Handler</title> |
| 7 | <link rel="stylesheet" href="extender-pattern-handler_files/site.css" type="text/css" media="all"> |
| 8 | <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
| 9 | </head><body> |
| 10 | <div class="title"><div class="logo"><a href="http://felix.apache.org/site/index.html"><img alt="Apache Felix" src="extender-pattern-handler_files/logo.png" border="0"></a></div><div class="header"><a href="http://www.apache.org/"><img alt="Apache" src="extender-pattern-handler_files/apache.png" border="0"></a></div></div> |
| 11 | <div class="menu"> |
| 12 | <ul> |
| 13 | <li><a href="http://felix.apache.org/site/news.html" title="news">news</a></li> |
| 14 | <li><a href="http://felix.apache.org/site/license.html" title="license">license</a></li> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 15 | <li><a href="http://felix.apache.org/site/downloads.cgi" rel="nofollow">downloads</a></li> |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 16 | <li><a href="http://felix.apache.org/site/documentation.html" title="documentation">documentation</a></li> |
| 17 | <li><a href="http://felix.apache.org/site/mailinglists.html" title="mailinglists">mailing lists</a></li> |
| 18 | <li><a href="http://felix.apache.org/site/contributing.html" title="Contributing">contributing</a></li> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 19 | <li><a href="http://www.apache.org/" rel="nofollow">asf</a></li> |
| 20 | <li><a href="http://www.apache.org/foundation/sponsorship.html" rel="nofollow">sponsorship</a></li> |
| 21 | <li><a href="http://www.apache.org/foundation/thanks.html" rel="nofollow">sponsors</a> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 22 | <!-- ApacheCon Ad --> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 23 | <iframe src="extender-pattern-handler_files/button.html" style="border-width: 0pt; float: left;" scrolling="no" frameborder="0" height="135" width="135"></iframe> |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 24 | <p style="height: 100px;"> |
| 25 | <!-- ApacheCon Ad --> |
| 26 | </p></li></ul> </div> |
| 27 | <div class="main"> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 28 | <style type="text/css"> |
| 29 | @import url(http://people.apache.org/~clement/ipojo/site/superfish.css); |
| 30 | </style> |
| 31 | |
| 32 | <style type="text/css"> |
| 33 | @import url(http://people.apache.org/~clement/ipojo/site/style.css); |
| 34 | </style> |
| 35 | |
| 36 | <p> |
| 37 | <script class="javascript" src="extender-pattern-handler_files/shCore.js"></script> |
| 38 | <script class="javascript" src="extender-pattern-handler_files/shBrushCSharp.js"></script> |
| 39 | <script class="javascript" src="extender-pattern-handler_files/shBrushPhp.js"></script> |
| 40 | <script class="javascript" src="extender-pattern-handler_files/shBrushJScript.js"></script> |
| 41 | <script class="javascript" src="extender-pattern-handler_files/shBrushVb.js"></script> |
| 42 | <script class="javascript" src="extender-pattern-handler_files/shBrushSql.js"></script> |
| 43 | <script class="javascript" src="extender-pattern-handler_files/shBrushXml.js"></script> |
| 44 | <script class="javascript" src="extender-pattern-handler_files/shBrushShell.js"></script> |
| 45 | <script class="javascript" src="extender-pattern-handler_files/shBrushDelphi.js"></script> |
| 46 | <script class="javascript" src="extender-pattern-handler_files/shBrushPython.js"></script> |
| 47 | <script class="javascript" src="extender-pattern-handler_files/shBrushJava.js"></script> |
| 48 | |
| 49 | <script type="text/javascript" src="extender-pattern-handler_files/jquery-1.js"></script> |
| 50 | <script type="text/javascript" src="extender-pattern-handler_files/hoverIntent.js"></script> |
| 51 | <script type="text/javascript" src="extender-pattern-handler_files/superfish.js"></script> |
| 52 | <script type="text/javascript" src="extender-pattern-handler_files/supersubs.js"></script> |
| 53 | |
| 54 | <script type="text/javascript"> |
| 55 | |
| 56 | $(document).ready(function(){ |
| 57 | $("ul.sf-menu").supersubs({ |
| 58 | minWidth: 14, // minimum width of sub-menus in em units |
| 59 | maxWidth: 30, // maximum width of sub-menus in em units |
| 60 | extraWidth: 1 // extra width can ensure lines don't sometimes turn over |
| 61 | // due to slight rounding differences and font-family |
| 62 | }).superfish(); // call supersubs first, then superfish, so that subs are |
| 63 | // not display:none when measuring. Call before initialising |
| 64 | // containing tabs for same reason. |
| 65 | }); |
| 66 | |
| 67 | </script> |
| 68 | </p><div class="main"> |
| 69 | <div class="page-header"> |
| 70 | <img src="extender-pattern-handler_files/header.png" class="header"> |
| 71 | <a href="http://ipojo.org/"><img src="extender-pattern-handler_files/ipojo.png" class="header-logo" width="225"></a> |
| 72 | <ul class="sf-menu sf-js-enabled sf-shadow" id="ipojo-menu"> |
| 73 | <li class="current"> |
| 74 | <!-- Menu Overview --> |
| 75 | <a href="" class="sf-with-ul">Overview<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a> |
| 76 | <ul style="float: none; width: 14em; display: none; visibility: hidden;"> |
| 77 | <li style="white-space: normal; float: left; width: 100%;"> |
| 78 | <a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo.html" title="Apache Felix iPOJO">Home</a> |
| 79 | </li> |
| 80 | <li style="white-space: normal; float: left; width: 100%;"> |
| 81 | <a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-why-choose-ipojo.html" title="apache-felix-ipojo-why-choose-ipojo">Why choose iPOJO</a> |
| 82 | </li> |
| 83 | <li style="white-space: normal; float: left; width: 100%;"> |
| 84 | <a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-successstories.html" title="apache-felix-ipojo-successstories">Success stories</a> |
| 85 | </li> |
| 86 | <li style="white-space: normal; float: left; width: 100%;"> |
| 87 | <a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-feature-overview.html" title="Apache Felix iPOJO Feature Overview">Features</a> |
| 88 | </li> |
| 89 | </ul> |
| 90 | </li> |
| 91 | |
| 92 | <li class=""> |
| 93 | <!-- Menu download --> |
| 94 | </li><li> |
| 95 | <a href="http://felix.apache.org/site/download.html" title="Download">Download </a> |
| 96 | </li> |
| 97 | |
| 98 | <li class=""> |
| 99 | <!-- Menu Documentation --> |
| 100 | <a href="" class="sf-with-ul">Documentation<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a> |
| 101 | <ul style="float: none; width: 14em; display: none; visibility: hidden;"> |
| 102 | <!-- sub- menu : getting started --> |
| 103 | <li style="white-space: normal; float: left; width: 100%;" class=""> |
| 104 | <a style="float: none; width: auto;" href="" class="sf-with-ul">Getting Started<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a> |
| 105 | <ul style="left: 14em; float: none; width: 14em; display: none; visibility: hidden;"> |
| 106 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-in-10-minutes.html" title="iPOJO in 10 minutes">iPOJO in 10 minutes</a></li> |
| 107 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/how-to-use-ipojo-annotations.html" title="How to use iPOJO Annotations">Using Annotations</a></li> |
| 108 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-hello-word-maven-based-tutorial.html" title="iPOJO Hello Word (Maven-Based) tutorial">Maven tutorial</a></li> |
| 109 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-advanced-tutorial.html" title="iPOJO Advanced Tutorial">Advanced tutorial</a></li> |
| 110 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-dosgi.html" title="apache-felix-ipojo-dosgi">Using Distributed OSGi</a></li> |
| 111 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-composition-tutorial.html" title="iPOJO Composition Tutorial">Application Composition</a></li> |
| 112 | </ul> |
| 113 | </li> <!-- end of getting started --> |
| 114 | <!-- sub menu : Describing Components --> |
| 115 | <li style="white-space: normal; float: left; width: 100%;" class=""> |
| 116 | <a style="float: none; width: auto;" href="http://felix.apache.org/site/describing-components.html" class="sf-with-ul">Describing components<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a> |
| 117 | <ul style="left: 14em; float: none; width: 14em; display: none; visibility: hidden;"> |
| 118 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/service-requirement-handler.html" title="Service Requirement Handler">Requiring a service</a></li> |
| 119 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/providing-osgi-services.html" title="Providing OSGi services">Providing a service</a></li> |
| 120 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/lifecycle-callback-handler.html" title="Lifecycle Callback Handler">Lifecycle management</a></li> |
| 121 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/configuration-handler.html" title="Configuration Handler">Configuration</a></li> |
| 122 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/architecture-handler.html" title="Architecture Handler">Introspection</a></li> |
| 123 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/controller-lifecycle-handler.html" title="Controller Lifecycle Handler">Impacting the lifecycle</a></li> |
| 124 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/event-admin-handlers.html" title="Event Admin Handlers">Asynchronous communication</a></li> |
| 125 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-jmx-handler.html" title="iPOJO JMX Handler">JMX management</a></li> |
| 126 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="" title="Extender Pattern Handler">Extender pattern</a></li> |
| 127 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/white-board-pattern-handler.html" title="White Board Pattern Handler">Whiteboard pattern</a></li> |
| 128 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/temporal-service-dependency.html" title="Temporal Service Dependency">Temporal dependencies</a></li> |
| 129 | </ul> |
| 130 | </li> <!-- End of describing components --> |
| 131 | <!-- sub- menu : User Guide --> |
| 132 | <li style="white-space: normal; float: left; width: 100%;" class=""> |
| 133 | <a style="float: none; width: auto;" href="" class="sf-with-ul">User Guide<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a> |
| 134 | <ul style="left: 14em; float: none; width: 14em; display: none; visibility: hidden;"> |
| 135 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/using-xml-schemas.html" title="Using XML Schemas">XML Schemas</a></li> |
| 136 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-api.html" title="apache-felix-ipojo-api">API</a></li> |
| 137 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-testing-components.html" title="apache-felix-ipojo-testing-components">Testing components</a></li> |
| 138 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-eclipse-integration.html" title="apache-felix-ipojo-eclipse-integration">Eclipse Integration</a></li> |
| 139 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-faq.html" title="iPOJO FAQ">FAQ</a></li> |
| 140 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-reference-card.html" title="iPOJO-Reference-Card">Reference Card</a></li> |
| 141 | </ul> |
| 142 | </li> <!-- end of user guide --> |
| 143 | <!-- sub- menu : Dev Guide --> |
| 144 | <li class="" style="white-space: normal; float: left; width: 100%;"> |
| 145 | <a style="float: none; width: auto;" href="" class="sf-with-ul">Advanced Topics<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a> |
| 146 | <ul style="left: 14em; float: none; width: 14em; display: none; visibility: hidden;"> |
| 147 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/ipojo/api/1.2.0" rel="nofollow">Javadoc</a></li> |
| 148 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/how-to-write-your-own-handler.html" title="How to write your own handler">Handler development</a></li> |
| 149 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/how-to-use-ipojo-manipulation-metadata.html" title="How to use iPOJO Manipulation Metadata">Manipulation Metadata </a></li> |
| 150 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/dive-into-the-ipojo-manipulation-depths.html" title="Dive into the iPOJO Manipulation depths">Dive into the iPOJO Manipulation depths</a></li> |
| 151 | </ul> |
| 152 | </li> <!-- End of Dev guide --> |
| 153 | </ul> |
| 154 | </li> <!-- End of doc --> |
| 155 | <!-- Menu 4 : Tools --> |
| 156 | <li class=""> |
| 157 | <a href="" class="sf-with-ul">Tools<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a> |
| 158 | <ul style="float: none; width: 14em; display: none; visibility: hidden;"> |
| 159 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-ant-task.html" title="iPOJO Ant Task">Ant Task</a></li> |
| 160 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-eclipse-plug-in.html" title="iPOJO Eclipse Plug-in">Eclipse Plugin</a></li> |
| 161 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-maven-plug-in.html" title="iPOJO Maven Plug-in">Maven Plugin</a></li> |
| 162 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-arch-command.html" title="iPOJO-Arch-Command"><tt>arch</tt> shell command</a></li> |
| 163 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-online-manipulator.html" title="apache-felix-ipojo-online-manipulator">Online Manipulator</a></li> |
| 164 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/ipojo-webconsole-plugin.html" title="iPOJO Webconsole Plugin">Webconsole plugin</a></li> |
| 165 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-junit4osgi.html" title="apache-felix-ipojo-junit4osgi">Junit4OSGi</a></li> |
| 166 | </ul> |
| 167 | </li><!-- End of tools --> |
| 168 | <!-- Menu 5 : Misc --> |
| 169 | <li class=""> |
| 170 | <a href="" class="sf-with-ul">Misc<span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span><span class="sf-sub-indicator"> »</span></a> |
| 171 | <ul style="float: none; width: 14em; display: none; visibility: hidden;"> |
| 172 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-issuestracker.html" title="apache-felix-ipojo-issuestracker">Issues Tracker</a></li> |
| 173 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-supportedvms.html" title="apache-felix-ipojo-supportedVMs">Supported JVMs</a></li> |
| 174 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/apache-felix-ipojo-supportedosgi.html" title="apache-felix-ipojo-supportedOSGi">Supported OSGi Implementations</a></li> |
| 175 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://ipojo-dark-side.blogspot.com/" rel="nofollow">iPOJO's Dark Side Blog</a></li> |
| 176 | <li style="white-space: normal; float: left; width: 100%;"><a style="float: none; width: auto;" href="http://felix.apache.org/site/article-presentations.html" title="Article & Presentations">Article & Presentations</a></li> |
| 177 | </ul> |
| 178 | </li><!-- End of misc --> |
| 179 | </ul> <!-- End of the menu --> |
| 180 | </div> <!-- Page header --> |
| 181 | |
| 182 | |
| 183 | <div class="content"> |
| 184 | |
| 185 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 186 | <h1><a name="ExtenderPatternHandler-Theextenderpatternhandler"></a>The extender pattern handler</h1> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 187 | <p><em>The objective of this handler is to simplify the development of |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 188 | extender-based architecture. This architecture-style is based on two |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 189 | different roles:</em></p> |
| 190 | <ul> |
| 191 | <li><em>The extender</em></li> |
| 192 | <li><em>The extensions</em></li> |
| 193 | </ul> |
| 194 | |
| 195 | |
| 196 | <div class="toc"> |
| 197 | <ul> |
| 198 | <li><a href="#ExtenderPatternHandler-TheExtenderpattern">The Extender pattern</a></li> |
| 199 | <li><a href="#ExtenderPatternHandler-Usingthehandler">Using the handler</a></li> |
| 200 | <li><a href="#ExtenderPatternHandler-Configuration">Configuration</a></li> |
| 201 | <li><a href="#ExtenderPatternHandler-Download">Download</a></li> |
| 202 | <li><a href="#ExtenderPatternHandler-Configuringthehandlerwithannotations">Configuring the handler with annotations</a></li> |
| 203 | <li><a href="#ExtenderPatternHandler-Amorerealisticexample">A more realistic example</a></li> |
| 204 | </ul></div> |
| 205 | |
| 206 | <h2><a name="ExtenderPatternHandler-TheExtenderpattern"></a>The Extender pattern</h2> |
| 207 | |
| 208 | <p>This architecture-style is based on two different roles:</p> |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 209 | <ul> |
| 210 | <li>The extender</li> |
| 211 | <li>The extension</li> |
| 212 | </ul> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 213 | |
| 214 | |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 215 | <p><img src="extender-pattern-handler_files/extender.png" border="0" align="absmiddle"></p> |
| 216 | |
| 217 | <p>The relation is basically a 1..n relation. The extender tracks |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 218 | extensions. The particularity of this architecture-style is that |
| 219 | extensions are packaged in different bundles. An extension is detected |
| 220 | by analyzing the bundle. Indeed these bundles can have a special mark |
| 221 | in their manifest of a special file...<br> |
| 222 | Implementing an extender pattern could be complex as the extender needs |
| 223 | to track these marks dynamically. When a bundle starts, it needs to |
| 224 | look at the mark. Then a bundle leave, the extender must release all |
| 225 | object created from this bundle.<br> |
| 226 | This handler tracks bundle for you based on the specified required |
| 227 | mark. At each time a matching bundle appears or disappears, a callback |
| 228 | is invoked. The mark is currently a header in the bundle manifest.<br> |
| 229 | Nowadays, a lot of frameworks use this pattern such as iPOJO it-self |
| 230 | (to find both bundles containing components and bundles adding a new |
| 231 | implementation type), Spring-DM ...</p> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 232 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 233 | <h2><a name="ExtenderPatternHandler-Usingthehandler"></a>Using the handler</h2> |
| 234 | <p>First of all, you need to configure the component type to use the handler such as:</p> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 235 | <div class="code"> |
| 236 | <div class="dp-highlighter"><table class="dp-xml" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td class="line1"><span></span><span class="tag"><</span><span>iPOJO xmlns:</span><span class="attribute">extender</span><span>=</span><span class="attribute-value">"org.apache.felix.ipojo.extender"</span><span>> </span></td></tr><tr><td class="line2"> <span class="tag"><</span><span>component </span></td></tr><tr><td class="line1"> <span class="attribute">classname</span><span>=</span><span class="attribute-value">"org.apache.felix.ipojo.extender.myextender"</span><span>> </span></td></tr><tr><td class="line2"> </td></tr><tr><td class="line1"> <span class="comments"><!-- Extender Pattern handler configuration --></span><span> </span></td></tr><tr><td class="line2"> <span class="tag"><</span><span>extender:extender </span></td></tr><tr><td class="line1"> <span class="attribute">extension</span><span>=</span><span class="attribute-value">"My-Extension"</span><span> </span></td></tr><tr><td class="line2"> <span class="attribute">onArrival</span><span>=</span><span class="attribute-value">"onBundleArrival"</span><span> </span></td></tr><tr><td class="line1"> <span class="attribute">onDeparture</span><span>=</span><span class="attribute-value">"onBundleDeparture"</span><span> </span></td></tr><tr><td class="line2"> <span class="tag">/></span><span> </span></td></tr><tr><td class="line1"> </td></tr><tr><td class="line2"> <span class="tag"><</span><span>callback </span><span class="attribute">transition</span><span>=</span><span class="attribute-value">"invalidate"</span><span> </span><span class="attribute">method</span><span>=</span><span class="attribute-value">"stopping"</span><span> </span><span class="tag">/></span><span> </span></td></tr><tr><td class="line1"> <span class="tag"><</span><span>callback </span><span class="attribute">transition</span><span>=</span><span class="attribute-value">"validate"</span><span> </span><span class="attribute">method</span><span>=</span><span class="attribute-value">"starting"</span><span> </span><span class="tag">/></span><span> </span></td></tr><tr><td class="line2"> <span class="tag"><</span><span>provides </span><span class="tag">/></span><span> </span></td></tr><tr><td class="line1"> <span class="tag"></</span><span>component</span><span class="tag">></span><span> </span></td></tr><tr><td class="line2"><span class="tag"></</span><span>iPOJO</span><span class="tag">></span><span> </span></td></tr></tbody></table></div><textarea style="display: none;" name="newcodemacro" class="xml:nocontrols:nogutter" rows="10" readonly="readonly"><iPOJO xmlns:extender="org.apache.felix.ipojo.extender"> |
| 237 | <component |
| 238 | classname="org.apache.felix.ipojo.extender.myextender"> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 239 | |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 240 | <!-- Extender Pattern handler configuration --> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 241 | <extender:extender |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 242 | extension="My-Extension" |
| 243 | onArrival="onBundleArrival" |
| 244 | onDeparture="onBundleDeparture" |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 245 | /> |
| 246 | |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 247 | <callback transition="invalidate" method="stopping" /> |
| 248 | <callback transition="validate" method="starting" /> |
| 249 | <provides /> |
| 250 | </component> |
| 251 | </iPOJO></textarea> |
| 252 | <script class="javascript"> |
| 253 | if(!window.newcodemacro_initialised) |
| 254 | { |
| 255 | window.newcodemacro_initialised = true; |
| 256 | window.oldonloadmethod = window.onload; |
| 257 | window.onload = function(){ |
| 258 | dp.SyntaxHighlighter.HighlightAll('newcodemacro'); |
| 259 | if(window.oldonloadmethod) |
| 260 | { |
| 261 | window.oldonloadmethod(); |
| 262 | } |
| 263 | } |
| 264 | } |
| 265 | |
| 266 | </script> |
| 267 | </div> |
| 268 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 269 | <p>Notice that, this handler is an external handler. So, it uses the "org.apache.felix.ipojo.extender" namespace.<br> |
| 270 | Once described, you can implement your component. The methods specified |
| 271 | methods will be called when a matching bundle arrives or leaves.<br> |
| 272 | In the previous example, these methods could be: </p> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 273 | <div class="code"> |
| 274 | <div class="dp-highlighter"><table class="dp-c" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td class="line1"><span></span><span class="keyword">void</span><span> onBundleArrival(Bundle bundle, String header) { </span></td></tr><tr><td class="line2"> <span class="comment">// Do something</span><span> </span></td></tr><tr><td class="line1">} </td></tr><tr><td class="line2"> </td></tr><tr><td class="line1"><span class="keyword">void</span><span> onBundleDeparture(Bundle bundle) { </span></td></tr><tr><td class="line2"> <span class="comment">// Do something</span><span> </span></td></tr><tr><td class="line1">} </td></tr></tbody></table></div><textarea style="display: none;" name="newcodemacro" class="java:nocontrols:nogutter" rows="10" readonly="readonly">void onBundleArrival(Bundle bundle, String header) { |
| 275 | // Do something |
| 276 | } |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 277 | |
| 278 | void onBundleDeparture(Bundle bundle) { |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 279 | // Do something |
| 280 | }</textarea> |
| 281 | <script class="javascript"> |
| 282 | if(!window.newcodemacro_initialised) |
| 283 | { |
| 284 | window.newcodemacro_initialised = true; |
| 285 | window.oldonloadmethod = window.onload; |
| 286 | window.onload = function(){ |
| 287 | dp.SyntaxHighlighter.HighlightAll('newcodemacro'); |
| 288 | if(window.oldonloadmethod) |
| 289 | { |
| 290 | window.oldonloadmethod(); |
| 291 | } |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | </script> |
| 296 | </div> |
| 297 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 298 | <p>Notice the different signatures of the methods. The arrival method |
| 299 | is called with the arriving bundle and the matching header value (i.e. |
| 300 | the value of the My-Extension header of the bundle manifest). The |
| 301 | departure method just receives the leaving bundle.</p> |
| 302 | <h2><a name="ExtenderPatternHandler-Configuration"></a>Configuration</h2> |
| 303 | <p>The handler has only three mandatory attributes:</p> |
| 304 | <ul> |
| 305 | <li>Extension: declaring the looked manifest header.</li> |
| 306 | <li>onArrival: declaring the method to invoke when a matching bundle arrives</li> |
| 307 | <li>onDeparture: declaring the method to invoke when a matching bundle leaves</li> |
| 308 | </ul> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 309 | |
| 310 | |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 311 | |
| 312 | |
| 313 | <div class="box"> |
| 314 | <div class="box-yellow-header"> |
| 315 | <div class="box-yellow-title"> |
| 316 | <img src="extender-pattern-handler_files/warning.gif"> <b>Called despite being invalid</b> |
| 317 | </div> |
| 318 | </div> |
| 319 | <div class="box-yellow-content"> |
| 320 | The implementation will be notified of arrivals and departures despite |
| 321 | the instance is invalid. Indeed, the implementation must release all |
| 322 | objects created from another bundle as soon it leaves. </div> |
| 323 | <div class="box-yellow-footer"></div> |
| 324 | </div> |
| 325 | |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 326 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 327 | <h2><a name="ExtenderPatternHandler-Download"></a>Download</h2> |
| 328 | <p>The handler is available on the <a href="http://felix.apache.org/site/download.html" title="Download">download</a> page.<br> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 329 | Sources are available on the Felix trunk at the following location: <a href="http://svn.apache.org/repos/asf/felix/trunk/ipojo/handler/extender/" rel="nofollow">http://svn.apache.org/repos/asf/felix/trunk/ipojo/handler/extender/</a></p> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 330 | |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 331 | <h2><a name="ExtenderPatternHandler-Configuringthehandlerwithannotations"></a>Configuring the handler with annotations</h2> |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 332 | |
| 333 | <p>It is possible to configure the handler with a simple annotation |
| 334 | available in the annotation pack ('annotation' project in the iPOJO |
| 335 | trunk). Here is an example of usage:</p> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 336 | <div class="code"> |
| 337 | <div class="dp-highlighter"><table class="dp-c" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td class="line1"><span></span><span class="keyword">import</span><span> org.apache.felix.ipojo.annotations.Component; </span></td></tr><tr><td class="line2"><span class="keyword">import</span><span> org.osgi.framework.Bundle; </span></td></tr><tr><td class="line1"><span class="preprocessor"></span></td></tr><tr><td class="line2"><span class="preprocessor">@Component</span><span> </span></td></tr><tr><td class="line1"><span class="preprocessor">@org.apache.felix.ipojo.extender.Extender(extension="foo", onArrival="onArrival", onDeparture="onDeparture")</span><span> </span></td></tr><tr><td class="line2"><span class="keyword">public</span><span> </span><span class="keyword">class</span><span> Extender { </span></td></tr><tr><td class="line1"> </td></tr><tr><td class="line2"> <span class="keyword">public</span><span> </span><span class="keyword">void</span><span> onArrival(Bundle bundle, String foo) { </span></td></tr><tr><td class="line1"> <span class="comment">// do something</span><span> </span></td></tr><tr><td class="line2"> } </td></tr><tr><td class="line1"> </td></tr><tr><td class="line2"> <span class="keyword">public</span><span> </span><span class="keyword">void</span><span> onDeparture(Bundle bundle) { </span></td></tr><tr><td class="line1"> <span class="comment">// do something</span><span> </span></td></tr><tr><td class="line2"> } </td></tr><tr><td class="line1">} </td></tr></tbody></table></div><textarea style="display: none;" name="newcodemacro" class="java:nocontrols:nogutter" rows="10" readonly="readonly">import org.apache.felix.ipojo.annotations.Component; |
| 338 | import org.osgi.framework.Bundle; |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 339 | |
| 340 | @Component |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 341 | @org.apache.felix.ipojo.extender.Extender(extension="foo", onArrival="onArrival", onDeparture="onDeparture") |
| 342 | public class Extender { |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 343 | |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 344 | public void onArrival(Bundle bundle, String foo) { |
| 345 | // do something |
| 346 | } |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 347 | |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 348 | public void onDeparture(Bundle bundle) { |
| 349 | // do something |
| 350 | } |
| 351 | }</textarea> |
| 352 | <script class="javascript"> |
| 353 | if(!window.newcodemacro_initialised) |
| 354 | { |
| 355 | window.newcodemacro_initialised = true; |
| 356 | window.oldonloadmethod = window.onload; |
| 357 | window.onload = function(){ |
| 358 | dp.SyntaxHighlighter.HighlightAll('newcodemacro'); |
| 359 | if(window.oldonloadmethod) |
| 360 | { |
| 361 | window.oldonloadmethod(); |
| 362 | } |
| 363 | } |
| 364 | } |
| 365 | |
| 366 | </script> |
| 367 | </div> |
| 368 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 369 | |
| 370 | <p>The <tt>extension</tt> attribute allows setting the bundle filter.</p> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 371 | |
| 372 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 373 | <h2><a name="ExtenderPatternHandler-Amorerealisticexample"></a>A more realistic example</h2> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 374 | <p>The Junit4OSGi framework, available <a href="https://svn.apache.org/repos/asf/felix/trunk/ipojo/examples/junit4osgi" rel="nofollow">here</a> |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 375 | , uses this handler to track Junit Test Suite offered by the installed |
| 376 | bundles. The Junit4Osgi bundle has a component using this handler to be |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 377 | notified when a bundle with the <tt>Test-Suite</tt> header appears or leaves. |
| 378 | <br clear="all"> |
| 379 | <br clear="all"></p> |
| Clement Escoffier | 130ca57 | 2008-10-13 07:33:03 +0000 | [diff] [blame] | 380 | |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 381 | </div> |
| 382 | <img src="extender-pattern-handler_files/footer.png" class="footer"> |
| 383 | </div> |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 384 | |
| 385 | <script type="text/javascript"> |
| 386 | var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); |
| 387 | document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); |
| 388 | </script><script src="extender-pattern-handler_files/ga.js" type="text/javascript"></script> |
| 389 | <script type="text/javascript"> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 390 | try{ |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 391 | var pageTracker = _gat._getTracker("UA-1518442-4"); |
| 392 | pageTracker._trackPageview(); |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 393 | } catch(err) {} |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 394 | </script> |
| Clement Escoffier | 580d190 | 2009-07-21 12:06:46 +0000 | [diff] [blame] | 395 | |
| Clement Escoffier | 3e0db1e | 2009-01-15 15:35:17 +0000 | [diff] [blame] | 396 | </div> |
| 397 | </body></html> |