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new 7e08826bc Updates stage by Jenkins
7e08826bc is described below
commit 7e08826bc6d8eff8b287100a119ba33b023ea523
Author: jenkins <[email protected]>
AuthorDate: Tue Apr 5 06:56:34 2022 +0000
Updates stage by Jenkins
---
content/plugins/index.html | 4 +-
content/plugins/plugins-architecture.html | 723 ++++++++++++++++++++++++++++++
2 files changed, 725 insertions(+), 2 deletions(-)
diff --git a/content/plugins/index.html b/content/plugins/index.html
index 4ee850aeb..0471b5fa9 100644
--- a/content/plugins/index.html
+++ b/content/plugins/index.html
@@ -130,12 +130,12 @@
<h1 id="plugin-developers-guide">Plugin Developers Guide</h1>
-<p>Apache Struts 2 provides a simple <a href="plugins">plugin architecture</a>
so that developers can extend the framework just by
+<p>Apache Struts 2 provides a simple <a href="plugins-architecture">plugin
architecture</a> so that developers can extend the framework just by
adding a JAR to the application’s classpath. Since plugins are contained in a
JAR, they are easy to share with others.
Several plugins are bundled with the framework, and others are available from
third-party sources.</p>
<ul>
- <li><a href="plugins">Plugins</a></li>
+ <li><a href="plugins-architecture">Plugins</a></li>
<li><a href="extending-an-application-with-custom-plugins">Extending an
Application with Custom Plugins</a></li>
</ul>
diff --git a/content/plugins/plugins-architecture.html
b/content/plugins/plugins-architecture.html
new file mode 100644
index 000000000..8e307c320
--- /dev/null
+++ b/content/plugins/plugins-architecture.html
@@ -0,0 +1,723 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+ <meta charset="UTF-8"/>
+ <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+ <meta name="Date-Revision-yyyymmdd" content="20140918"/>
+ <meta http-equiv="Content-Language" content="en"/>
+ <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
+
+ <title>Plugins</title>
+
+ <link
href="//fonts.googleapis.com/css?family=Source+Sans+Pro:300,400,600,700,400italic,600italic,700italic"
rel="stylesheet" type="text/css">
+ <link
href="//netdna.bootstrapcdn.com/font-awesome/4.0.3/css/font-awesome.css"
rel="stylesheet">
+ <link href="/css/main.css" rel="stylesheet">
+ <link href="/css/custom.css" rel="stylesheet">
+ <link href="/highlighter/github-theme.css" rel="stylesheet">
+
+ <script src="//code.jquery.com/jquery-1.11.0.min.js"></script>
+ <script type="text/javascript" src="/bootstrap/js/bootstrap.js"></script>
+ <script type="text/javascript" src="/js/community.js"></script>
+</head>
+<body>
+
+<a href="http://github.com/apache/struts"; class="github-ribbon">
+ <img style="position: absolute; right: 0; border: 0;"
src="https://s3.amazonaws.com/github/ribbons/forkme_right_red_aa0000.png";
alt="Fork me on GitHub">
+</a>
+
+<header>
+ <nav>
+ <div role="navigation" class="navbar navbar-default navbar-fixed-top">
+ <div class="container">
+ <div class="navbar-header">
+ <button type="button" data-toggle="collapse"
data-target="#struts-menu" class="navbar-toggle">
+ Menu
+ <span class="sr-only">Toggle navigation</span>
+ <span class="icon-bar"></span>
+ <span class="icon-bar"></span>
+ <span class="icon-bar"></span>
+ </button>
+ <a href="/index.html" class="navbar-brand logo"><img
src="/img/struts-logo.svg"></a>
+ </div>
+ <div id="struts-menu" class="navbar-collapse collapse">
+ <ul class="nav navbar-nav">
+ <li class="dropdown">
+ <a data-toggle="dropdown" href="#" class="dropdown-toggle">
+ Home<b class="caret"></b>
+ </a>
+ <ul class="dropdown-menu">
+ <li><a href="/index.html">Welcome</a></li>
+ <li><a href="/download.cgi">Download</a></li>
+ <li><a href="/releases.html">Releases</a></li>
+ <li><a href="/announce-2022.html">Announcements</a></li>
+ <li><a href="http://www.apache.org/licenses/";>License</a></li>
+ <li><a
href="https://www.apache.org/foundation/thanks.html";>Thanks!</a></li>
+ <li><a
href="https://www.apache.org/foundation/sponsorship.html";>Sponsorship</a></li>
+ </ul>
+ </li>
+ <li class="dropdown">
+ <a data-toggle="dropdown" href="#" class="dropdown-toggle">
+ Support<b class="caret"></b>
+ </a>
+ <ul class="dropdown-menu">
+ <li><a href="/mail.html">User Mailing List</a></li>
+ <li><a href="https://issues.apache.org/jira/browse/WW";>Issue
Tracker</a></li>
+ <li><a href="/security.html">Reporting Security Issues</a></li>
+ <li class="divider"></li>
+ <li><a
href="https://cwiki.apache.org/confluence/display/WW/Migration+Guide";>Version
Notes</a></li>
+ <li><a
href="https://cwiki.apache.org/confluence/display/WW/Security+Bulletins";>Security
Bulletins</a></li>
+ <li class="divider"></li>
+ <li><a href="/maven/project-info.html">Maven Project
Info</a></li>
+ <li><a href="/maven/struts2-core/dependencies.html">Struts
Core Dependencies</a></li>
+ <li><a href="/maven/struts2-plugins/modules.html">Plugin
Dependencies</a></li>
+ </ul>
+ </li>
+ <li class="dropdown">
+ <a data-toggle="dropdown" href="#" class="dropdown-toggle">
+ Documentation<b class="caret"></b>
+ </a>
+ <ul class="dropdown-menu">
+ <li><a href="/birdseye.html">Birds Eye</a></li>
+ <li><a href="/primer.html">Key Technologies</a></li>
+ <li><a href="/kickstart.html">Kickstart FAQ</a></li>
+ <li><a
href="https://cwiki.apache.org/confluence/display/WW/Home";>Wiki</a></li>
+ <li class="divider"></li>
+ <li><a href="/getting-started/">Getting Started</a></li>
+ <li><a href="/security/">Security Guide</a></li>
+ <li><a href="/core-developers/">Core Developers Guide</a></li>
+ <li><a href="/tag-developers/">Tag Developers Guide</a></li>
+ <li><a href="/maven-archetypes/">Maven Archetypes</a></li>
+ <li><a href="/plugins/">Plugins</a></li>
+ <li><a href="/maven/struts2-core/apidocs/index.html">Struts
Core API</a></li>
+ <li><a href="/tag-developers/tag-reference.html">Tag
reference</a></li>
+ <li><a
href="https://cwiki.apache.org/confluence/display/WW/FAQs";>FAQs</a></li>
+ <li><a
href="http://cwiki.apache.org/S2PLUGINS/home.html";>Plugin registry</a></li>
+ </ul>
+ </li>
+ <li class="dropdown">
+ <a data-toggle="dropdown" href="#" class="dropdown-toggle">
+ Contributing<b class="caret"></b>
+ </a>
+ <ul class="dropdown-menu">
+ <li><a href="/youatstruts.html">You at Struts</a></li>
+ <li><a href="/helping.html">How to Help FAQ</a></li>
+ <li><a href="/dev-mail.html">Development Lists</a></li>
+ <li class="divider"></li>
+ <li><a href="/submitting-patches.html">Submitting
patches</a></li>
+ <li><a href="/builds.html">Source Code and Builds</a></li>
+ <li><a href="/coding-standards.html">Coding standards</a></li>
+ <li><a href="/contributors/">Contributors Guide</a></li>
+ <li class="divider"></li>
+ <li><a href="/release-guidelines.html">Release
Guidelines</a></li>
+ <li><a href="/bylaws.html">PMC Charter</a></li>
+ <li><a href="/volunteers.html">Volunteers</a></li>
+ <li><a
href="https://gitbox.apache.org/repos/asf?p=struts.git";>Source
Repository</a></li>
+ <li><a href="/updating-website.html">Updating the
website</a></li>
+ </ul>
+ </li>
+ <li class="apache"><a href="http://www.apache.org/";><img
src="/img/apache.png"></a></li>
+ </ul>
+ </div>
+ </div>
+ </div>
+ </nav>
+</header>
+
+
+<article class="container">
+ <section class="col-md-12">
+ <a class="edit-on-gh"
href="https://github.com/apache/struts-site/edit/master/source/plugins/plugins-architecture.md";
title="Edit this page on GitHub">Edit on GitHub</a>
+
+ <a href="index.html" title="back to Plugins"><< back to Plugins</a>
+
+ <h1 class="no_toc" id="plugins">Plugins</h1>
+
+<ul id="markdown-toc">
+ <li><a href="#static-resources" id="markdown-toc-static-resources">Static
resources</a></li>
+ <li><a href="#extension-points" id="markdown-toc-extension-points">Extension
Points</a></li>
+ <li><a href="#plugin-examples" id="markdown-toc-plugin-examples">Plugin
Examples</a> <ul>
+ <li><a href="#sitemesh-plugin"
id="markdown-toc-sitemesh-plugin">Sitemesh plugin</a></li>
+ <li><a href="#tiles-plugin" id="markdown-toc-tiles-plugin">Tiles
plugin</a></li>
+ </ul>
+ </li>
+ <li><a href="#developing-new-extension-point"
id="markdown-toc-developing-new-extension-point">Developing new extension
point</a> <ul>
+ <li><a href="#extension-point-provided-by-the-core"
id="markdown-toc-extension-point-provided-by-the-core">Extension point provided
by the Core</a></li>
+ <li><a href="#extension-point-provided-by-a-plugin"
id="markdown-toc-extension-point-provided-by-a-plugin">Extension point provided
by a plugin</a></li>
+ </ul>
+ </li>
+ <li><a href="#plugin-registry" id="markdown-toc-plugin-registry">Plugin
Registry</a></li>
+</ul>
+
+<p>Struts 2 plugins contain classes and configuration that extend, replace, or
add to existing Struts framework functionality.
+A plugin can be installed by adding its JAR file to the application’s class
path, in addition to the JAR files to fulfill
+whatever dependencies the plugin itself may have. To configure the plugin, the
JAR should contain a <code class="highlighter-rouge">struts-plugin.xml</code>
+file, which follows the same format as an ordinary <code
class="highlighter-rouge">struts.xml</code> file.</p>
+
+<p>Since a plugin can contain the <code
class="highlighter-rouge">struts-plugin.xml</code> file, it has the ability
to:</p>
+<ul>
+ <li>Define new packages with results, interceptors, and/or actions</li>
+ <li>Override framework constants</li>
+ <li>Introduce new extension point implementation classes</li>
+</ul>
+
+<p>Many popular but optional features of the framework are distributed as
plugins. An application can retain all the plugins
+provided with the distribution, or just include the ones it uses. Plugins can
be used to organize application code
+or to distribute code to third-parties.</p>
+
+<p>Packages defined in a plugin can have parent packages that are defined in
another plugin. Plugins may define
+configuration elements with classes not contained in the plugin. Any classes
not included in the plugin’s JAR must be
+on the application’s classpath at runtime. As from Struts 2.3.5</p>
+
+<p>The framework loads its default configuration first, then any plugin
configuration files found in others JARs
+on the classpath, and finally the “bootstrap” <code
class="highlighter-rouge">struts.xml</code>.</p>
+
+<ol>
+ <li><code class="highlighter-rouge">struts-default.xml</code> (bundled in
the Core JAR)</li>
+ <li><code class="highlighter-rouge">struts-plugin.xml</code> (as many as can
be found in other JARs)</li>
+ <li><code class="highlighter-rouge">struts.xml</code> (provided by your
application)</li>
+</ol>
+
+<p>Since the <code class="highlighter-rouge">struts.xml</code> file is always
loaded last, it can make use of any resources provided by the plugins bundled
+with the distribution, or any other plugins available to an application.</p>
+
+<h2 id="static-resources">Static resources</h2>
+
+<p>To include static resources in your plugins add them under “/static” in
your jar. And include them in your page using
+“/static” as the path, like in the following example:</p>
+
+<pre><code class="language-ftl"><!-- Assuming /static/main.css is inside a
plugin jar, to add it to the page: -->
+
+<@s.url value="/struts/main.css" var="css" />
+<link rel="stylesheet" type="text/css" href="%{#css}" />
+</code></pre>
+
+<p>Read also <a href="../core-developers/static-content">Static Content</a>
and JavaDoc of <a
href="https://struts.apache.org/maven/struts2-core/apidocs/org/apache/struts2/dispatcher/StaticContentLoader";>StaticContentLoader</a>.</p>
+
+<h2 id="extension-points">Extension Points</h2>
+
+<p>Extension points allow a plugin to override a key class in the Struts
framework with an alternate implementation.
+For example, a plugin could provide a new class to create Action classes or
map requests to Actions.</p>
+
+<p>The following extension points are available in Struts 2:</p>
+
+<table>
+ <thead>
+ <tr>
+ <th>Property</th>
+ <th>Description</th>
+ <th>Scope</th>
+ <th>Type</th>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>struts.objectFactory</td>
+ <td>Creates actions, results, and interceptors</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.ObjectFactory</td>
+ </tr>
+ <tr>
+ <td>struts.objectFactory.actionFactory</td>
+ <td>Dedicated factory used to create Actions, you can implement/extend
existing one instead of defining new ObjectFactory</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.factory.ActionFactory</td>
+ </tr>
+ <tr>
+ <td>struts.objectFactory.resultFactory</td>
+ <td>Dedicated factory used to create Results, you can implement/extend
existing one instead of defining new ObjectFactory</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.factory.ResultFactory</td>
+ </tr>
+ <tr>
+ <td>struts.objectFactory.interceptorFactory</td>
+ <td>Dedicated factory used to create Interceptors, you can
implement/extend existing one instead of defining new ObjectFactory</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.factory.InterceptorFactory</td>
+ </tr>
+ <tr>
+ <td>struts.objectFactory.converterFactory</td>
+ <td>Dedicated factory used to create TypeConverters, you can
implement/extend existing one instead of defining new ObjectFactory</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.factory.ConverterFactory</td>
+ </tr>
+ <tr>
+ <td>struts.objectFactory.validatorFactory</td>
+ <td>Dedicated factory used to create Validators, you can
implement/extend existing one instead of defining new ObjectFactory</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.factory.ValidatorFactory</td>
+ </tr>
+ <tr>
+ <td>struts.actionProxyFactory</td>
+ <td>Creates the ActionProxy</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.ActionProxyFactory</td>
+ </tr>
+ <tr>
+ <td>struts.objectTypeDeterminer</td>
+ <td>Determines what the key and element class of a Map or Collection
should be</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.util.ObjectTypeDeterminer</td>
+ </tr>
+ <tr>
+ <td>struts.mapper.class</td>
+ <td>Determines the ActionMapping from a request and a URI from an
ActionMapping</td>
+ <td>singleton</td>
+ <td>org.apache.struts2.dispatcher.mapper.ActionMapper</td>
+ </tr>
+ <tr>
+ <td>struts.multipart.parser</td>
+ <td>Parses a multipart request (file upload)</td>
+ <td>per request</td>
+ <td>org.apache.struts2.dispatcher.multipart.MultiPartRequest</td>
+ </tr>
+ <tr>
+ <td>struts.freemarker.manager.classname</td>
+ <td>Loads and processes Freemarker templates</td>
+ <td>singleton</td>
+ <td>org.apache.struts2.views.freemarker.FreemarkerManager</td>
+ </tr>
+ <tr>
+ <td>struts.velocity.manager.classname</td>
+ <td>Loads and processes Velocity templates</td>
+ <td>singleton</td>
+ <td>org.apache.struts2.views.velocity.VelocityManager</td>
+ </tr>
+ <tr>
+ <td>struts.actionValidatorManager</td>
+ <td>Main interface for validation managers (regular and annotation
based). Handles both the loading of configuration and the actual validation
(since 2.1)</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.validator.ActionValidatorManager</td>
+ </tr>
+ <tr>
+ <td>struts.valueStackFactory</td>
+ <td>Creates value stacks (since 2.1)</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.util.ValueStackFactory</td>
+ </tr>
+ <tr>
+ <td>struts.reflectionProvider</td>
+ <td>Provides reflection services, key place to plug in a custom
expression language (since 2.1)</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.reflection.ReflectionProvider</td>
+ </tr>
+ <tr>
+ <td>struts.reflectionContextFactory</td>
+ <td>Creates reflection context maps used for reflection and expression
language operations (since 2.1)</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.reflection.ReflectionContextFactory</td>
+ </tr>
+ <tr>
+ <td>N/A</td>
+ <td>All beans registered as PackageProvider implementations will be
automatically included in configuration building (since 2.1)</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.config.PackageProvider</td>
+ </tr>
+ <tr>
+ <td>struts.patternMatcher</td>
+ <td>Matches patterns, such as action names, generally used in
configuration (since 2.1)</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.util.PatternMatcher</td>
+ </tr>
+ <tr>
+ <td>struts.staticContentLoader</td>
+ <td>Loads static resources (since 2.1)</td>
+ <td>singleton</td>
+ <td>org.apache.struts2.views.dispatcher.DefaultStaticContentLoader</td>
+ </tr>
+ <tr>
+ <td>struts.xworkConverter</td>
+ <td>Handles conversion logic and allows to load custom converters per
class or per action</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.impl.XWorkConverter</td>
+ </tr>
+ <tr>
+ <td>struts.localeProviderFactory</td>
+ <td>Allows provide custom LocaleProvider for whole application</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.LocaleProviderFactory</td>
+ </tr>
+ <tr>
+ <td>struts.urlRenderer</td>
+ <td>Allows provide custom implementation of environment specific URL
rendering/creating class</td>
+ <td>singleton</td>
+ <td>org.apache.struts2.components.UrlRenderer</td>
+ </tr>
+ <tr>
+ <td>struts.unknownHandlerManager</td>
+ <td>Implementation of this interface allows handle logic of unknown
Actions, Methods or Results</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.UnknownHandlerManager</td>
+ </tr>
+ <tr>
+ <td>struts.view.urlHelper</td>
+ <td>Helper class used with URLRenderer to provide exact logic for
building URLs</td>
+ <td>singleton</td>
+ <td>org.apache.struts2.views.util.UrlHelper</td>
+ </tr>
+ <tr>
+ <td>struts.fileManagerFactory</td>
+ <td>Used to create FileManager instance to access files on the File
System as also to monitor if reload is needed, can be implemented / overwritten
to meet specific an application server needs</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.FileManagerFactory</td>
+ </tr>
+ <tr>
+ <td>struts.converter.collection</td>
+ <td>Converter used to convert any object to Collection and back</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.impl.CollectionConverter</td>
+ </tr>
+ <tr>
+ <td>struts.converter.array</td>
+ <td>Converter used to convert any object to Array and back</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.impl.ArrayConverter</td>
+ </tr>
+ <tr>
+ <td>struts.converter.date</td>
+ <td>Converter used to convert any object to Date and back</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.impl.DateConverter</td>
+ </tr>
+ <tr>
+ <td>struts.converter.number</td>
+ <td>Converter used to convert any object to Number and back</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.impl.NumberConverter</td>
+ </tr>
+ <tr>
+ <td>struts.converter.string</td>
+ <td>Converter used to convert any object to String and back</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.impl.StringConverter</td>
+ </tr>
+ <tr>
+ <td>struts.conversion.properties.processor</td>
+ <td>Process Properties to create converters</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.ConversionPropertiesProcessor</td>
+ </tr>
+ <tr>
+ <td>struts.converter.file.processor</td>
+ <td>Process {class}-conversion.properties file create converters</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.ConversionPropertiesProcessor</td>
+ </tr>
+ <tr>
+ <td>struts.converter.annotation.processor</td>
+ <td>Process TypeConversion annotation to create converters</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.ConversionAnnotationProcessor</td>
+ </tr>
+ <tr>
+ <td>struts.converter.creator</td>
+ <td>Creates user converters</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.TypeConverterCreator</td>
+ </tr>
+ <tr>
+ <td>struts.converter.holder</td>
+ <td>Holds user converters’ instances</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.conversion.TypeConverterHolder</td>
+ </tr>
+ <tr>
+ <td>struts.expression.parser</td>
+ <td>Used to parse expressions like ${foo.bar} or %{bar.foo} but it is up
tp the TextParser’s implementation what kind of opening char to use (#, $, %,
etc)</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.util.TextParser</td>
+ </tr>
+ <tr>
+ <td>struts.excludedPatterns.checker</td>
+ <td>Used across different interceptors to check if given string matches
one of the excluded patterns</td>
+ <td>request</td>
+ <td>com.opensymphony.xwork2.ExcludedPatternsChecker</td>
+ </tr>
+ <tr>
+ <td>struts.acceptedPatterns.checker</td>
+ <td>Used across different interceptors to check if given string matches
one of the accepted patterns</td>
+ <td>request</td>
+ <td>com.opensymphony.xwork2.AcceptedPatternsChecker</td>
+ </tr>
+ <tr>
+ <td>struts.contentTypeMatcher</td>
+ <td>Matches content type of uploaded files (since 2.3.22)</td>
+ <td>singleton</td>
+ <td>org.apache.struts2.util.ContentTypeMatcher</td>
+ </tr>
+ <tr>
+ <td>struts.localizedTextProvider</td>
+ <td>Provides access to resource bundles used to localise messages (since
2.5.11)</td>
+ <td>singleton</td>
+ <td>com.opensymphony.xwork2.LocalizedTextProvider</td>
+ </tr>
+ <tr>
+ <td>struts.date.formatter</td>
+ <td>Allow define a date formatter used by <code
class="highlighter-rouge"><s:date/></code> tag (since 6.0.0)</td>
+ <td>singleton</td>
+ <td>org.apache.struts2.components.date.DateFromatter</td>
+ </tr>
+ </tbody>
+</table>
+
+<h2 id="plugin-examples">Plugin Examples</h2>
+
+<p>Let’s look at two similar but different plugins bundled with the core
distribution.</p>
+
+<h3 id="sitemesh-plugin">Sitemesh plugin</h3>
+
+<p><a href="http://opensymphony.com/sitemesh/";>SiteMesh</a> is a popular
alternative to Tiles. SiteMesh provides a common look-and-feel
+to an application’s pages by automatically wrapping a plain page with common
elements like headers and menubars.</p>
+
+<p>The <code class="highlighter-rouge">sitemesh-plugin.jar</code> contains
several classes, a standard JAR manifest, and a plugin configuration file.</p>
+
+<div class="language-text highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> + META-INF/
+ + manifest.mf
+ + org
+ + apache
+ + struts2
+ + sitemesh
+ + FreeMarkerPageFilter.class
+ + TemplatePageFilter.class
+ + VelocityPageFilter.class
+ + struts-plugin.xml
+</code></pre></div></div>
+
+<p>While the SiteMesh Plugin doesn’t provide any new results, interceptors, or
actions, or even extend any Struts integration
+points, it does need to know what settings have been enabled in the Struts
framework. Therefore, its <code
class="highlighter-rouge">struts-plugin.xml</code> looks like this:</p>
+
+<div class="language-xml highlighter-rouge"><div class="highlight"><pre
class="highlight"><code><span class="cp"><?xml version="1.0"
encoding="UTF-8" ?></span>
+<span class="c"><!--
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+--></span>
+<span class="cp"><!DOCTYPE struts PUBLIC
+ "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
+ "http://struts.apache.org/dtds/struts-2.5.dtd"></span>
+
+<span class="nt"><struts></span>
+ <span class="nt"><bean</span> <span class="na">class=</span><span
class="s">"org.apache.struts2.sitemesh.FreemarkerPageFilter"</span> <span
class="na">static=</span><span class="s">"true"</span> <span
class="na">optional=</span><span class="s">"true"</span><span
class="nt">/></span>
+ <span class="nt"><bean</span> <span class="na">class=</span><span
class="s">"org.apache.struts2.sitemesh.VelocityPageFilter"</span> <span
class="na">static=</span><span class="s">"true"</span> <span
class="na">optional=</span><span class="s">"true"</span><span
class="nt">/></span>
+<span class="nt"></struts></span>
+
+</code></pre></div></div>
+
+<p>The two bean elements, with the “static” flag enabled, tell Struts to
inject the current settings and framework objects
+into static property setters on startup. This allows, for example, the
FreeMarkerPageFilter class to get an instance
+of the Struts FreemarkerManager and the current encoding setting.</p>
+
+<h3 id="tiles-plugin">Tiles plugin</h3>
+
+<p><a href="http://struts.apache.org/struts-sandbox/tiles/index";>Tiles</a> is
a popular alternative to SiteMesh. Tiles provides
+a common look-and-feel to an application’s pages by breaking the page down
into common fragments or “tiles”.</p>
+
+<p>The <code class="highlighter-rouge">tiles-plugin.jar</code> contains
several classes, a standard JAR manifest, and a configuration file.</p>
+
+<div class="language-text highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> + META-INF/
+ + manifest.mf
+ + org
+ + apache
+ + struts2
+ + tiles
+ + StrutsTilesListener.class
+ + StrutsTileUtilImpl.class
+ + views
+ + tiles
+ + TilesResult.class
+ + struts-plugin.xml
+</code></pre></div></div>
+
+<p>Since the Tiles Plugin does need to register configuration elements, a
result class, it provides a <code
class="highlighter-rouge">struts-plugin.xml</code> file.</p>
+
+<h2 id="developing-new-extension-point">Developing new extension point</h2>
+
+<p>An extension point it’s a name which will be used to locate other beans by
the name and inject them into a given place.
+Extension point isn’t a bean, you cannot inject it. It’s a bridge between your
interface/class and the final implementation,
+provided either by a plugin or by a user.</p>
+
+<p>If needed you can define your own extension point. This can happen in two
ways: either define it in the Struts Core,
+or define the extension in the plugin you are developing.</p>
+
+<h3 id="extension-point-provided-by-the-core">Extension point provided by the
Core</h3>
+
+<p>First step is to name your extension point, basically we are using a
pattern like follow:</p>
+<div class="highlighter-rouge"><div class="highlight"><pre
class="highlight"><code>struts.<component | functionallity>.<name of
the extebsion point>
+</code></pre></div></div>
+
+<p>e.g.: <code class="highlighter-rouge">struts.date.formatter</code>.</p>
+
+<p>Now you must provide an interface or a class as the extension point, it
will be used by others to implement they own behaviour
+of the extension point, e.g.: <code
class="highlighter-rouge">org.apache.struts2.components.date.DateFormatter</code>.</p>
+
+<p>The next step is to tie the name of the extension point with the
interface/class. It happens in <code
class="highlighter-rouge">StrutsBeanSelectionProvider</code></p>
+
+<p>by using <code class="highlighter-rouge">alias()</code> method as below:</p>
+<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code><span class="n">alias</span><span
class="o">(</span><span class="n">DateFormatter</span><span
class="o">.</span><span class="na">class</span><span class="o">,</span> <span
class="n">StrutsConstants</span><span class="o">.</span><span
class="na">STRUTS_DATE_FORMATTER</span><span class="o">,</span> <span
class="n">builder</span><span class="o">,</span> <span
class="n">props</span><span class="o [...]
+</code></pre></div></div>
+
+<p>as you can see you must provide:</p>
+<ul>
+ <li><code class="highlighter-rouge">Class<?></code> class behind the
extension point, which is used by users to implement the extension point</li>
+ <li><code class="highlighter-rouge">String</code> a key, the name of the
extension point</li>
+ <li><code class="highlighter-rouge">ContainerBuilder</code> builder used to
setup the Container</li>
+ <li><code class="highlighter-rouge">Properties</code> additional properties
when needed</li>
+ <li><code class="highlighter-rouge">Scope</code> scope of the extension
point, all the beans extneding the extension point must have the same scope</li>
+</ul>
+
+<p>Having all that set, you can define where to use the extension point by
injecting beans implementing it by using <code
class="highlighter-rouge">@Inject</code></p>
+
+<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code><span class="nd">@Inject</span>
+<span class="kd">public</span> <span class="kt">void</span> <span
class="nf">setDateFormatter</span><span class="o">(</span><span
class="n">DateFormatter</span> <span class="n">dateFormatter</span><span
class="o">)</span> <span class="o">{</span>
+ <span class="k">this</span><span class="o">.</span><span
class="na">dateFormatter</span> <span class="o">=</span> <span
class="n">dateFormatter</span><span class="o">;</span>
+<span class="o">}</span>
+</code></pre></div></div>
+
+<p>you can use <code class="highlighter-rouge">optional = true</code> if the
implementation is not required, yet please remember to handle <code
class="highlighter-rouge">null</code> in such case.</p>
+
+<p>All the above steps have defined a new extension point, now you can
implement a bean which will be <em>bridged</em> throughout
+the extension point with the <code class="highlighter-rouge">@Inject</code>.
Just implement the interface/class used to define the extension point and define
+the bean in <code class="highlighter-rouge">struts-default.xml</code>:</p>
+
+<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code><span class="kd">public</span> <span
class="kd">class</span> <span class="nc">DateTimeFormatterAdapter</span> <span
class="kd">implements</span> <span class="n">DateFormatter</span> <span
class="o">{</span>
+
+ <span class="nd">@Override</span>
+ <span class="kd">public</span> <span class="n">String</span> <span
class="nf">format</span><span class="o">(</span><span
class="n">TemporalAccessor</span> <span class="n">temporal</span><span
class="o">,</span> <span class="n">String</span> <span
class="n">format</span><span class="o">)</span> <span class="o">{</span>
+ <span class="n">DateTimeFormatter</span> <span
class="n">dtf</span><span class="o">;</span>
+ <span class="n">Locale</span> <span class="n">locale</span> <span
class="o">=</span> <span class="n">ActionContext</span><span
class="o">.</span><span class="na">getContext</span><span
class="o">().</span><span class="na">getLocale</span><span class="o">();</span>
+ <span class="k">if</span> <span class="o">(</span><span
class="n">format</span> <span class="o">==</span> <span
class="kc">null</span><span class="o">)</span> <span class="o">{</span>
+ <span class="n">dtf</span> <span class="o">=</span> <span
class="n">DateTimeFormatter</span><span class="o">.</span><span
class="na">ofLocalizedDateTime</span><span class="o">(</span><span
class="n">FormatStyle</span><span class="o">.</span><span
class="na">MEDIUM</span><span class="o">)</span>
+ <span class="o">.</span><span
class="na">withLocale</span><span class="o">(</span><span
class="n">locale</span><span class="o">);</span>
+ <span class="o">}</span> <span class="k">else</span> <span
class="o">{</span>
+ <span class="n">dtf</span> <span class="o">=</span> <span
class="n">DateTimeFormatter</span><span class="o">.</span><span
class="na">ofPattern</span><span class="o">(</span><span
class="n">format</span><span class="o">,</span> <span
class="n">locale</span><span class="o">);</span>
+ <span class="o">}</span>
+ <span class="k">return</span> <span class="n">dtf</span><span
class="o">.</span><span class="na">format</span><span class="o">(</span><span
class="n">temporal</span><span class="o">);</span>
+ <span class="o">}</span>
+
+<span class="o">}</span>
+</code></pre></div></div>
+
+<div class="language-xml highlighter-rouge"><div class="highlight"><pre
class="highlight"><code><span class="nt"><bean</span> <span
class="na">type=</span><span
class="s">"org.apache.struts2.components.date.DateFormatter"</span>
+ <span class="na">name=</span><span class="s">"dateTimeFormatter"</span>
+ <span class="na">class=</span><span
class="s">"org.apache.struts2.components.date.DateTimeFormatterAdapter"</span>
+ <span class="na">scope=</span><span class="s">"singleton"</span><span
class="nt">/></span>
+</code></pre></div></div>
+
+<p>The <code class="highlighter-rouge">name</code> attribute it’s of your
choice, it just needs to be unique.</p>
+
+<p>And the final step is to use the new bean with the extension point, this
will happen in <code class="highlighter-rouge">default.properties</code>:</p>
+
+<div class="highlighter-rouge"><div class="highlight"><pre
class="highlight"><code>struts.date.formatter=dateTimeFormatter
+</code></pre></div></div>
+
+<p>and done!</p>
+
+<p>If a user would like to provide its own implementation they just needs to
implement the interface, define a bean
+in <code class="highlighter-rouge">struts.xml</code> with a name and then tie
it to the extension point overriding the one provided by the framework:</p>
+
+<div class="language-xml highlighter-rouge"><div class="highlight"><pre
class="highlight"><code><span class="nt"><bean</span> <span
class="na">type=</span><span
class="s">"org.apache.struts2.components.date.DateFormatter"</span>
+ <span class="na">name=</span><span
class="s">"myDateTimeFormatter"</span>
+ <span class="na">class=</span><span
class="s">"com.company.date.MyDateTimeFormatterAdapter"</span>
+ <span class="na">scope=</span><span class="s">"singleton"</span><span
class="nt">/></span>
+</code></pre></div></div>
+
+<div class="highlighter-rouge"><div class="highlight"><pre
class="highlight"><code>struts.date.formatter=myDateTimeFormatter
+</code></pre></div></div>
+
+<h3 id="extension-point-provided-by-a-plugin">Extension point provided by a
plugin</h3>
+
+<p>It’s very the like as above except that the plugin must provide a <code
class="highlighter-rouge">bean-selection</code> configuration option in <code
class="highlighter-rouge">struts-plugin.xml</code>.
+The <code class="highlighter-rouge">bean-selection</code> option represents an
implementation of a class <code
class="highlighter-rouge">org.apache.struts2.config.AbstractBeanSelectionProvider</code>
+with <em>no-arguments</em> constructor:</p>
+
+<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code><span class="kd">public</span> <span
class="kd">class</span> <span class="nc">VelocityBeanSelectionProvider</span>
<span class="kd">extends</span> <span
class="n">AbstractBeanSelectionProvider</span> <span class="o">{</span>
+
+ <span class="nd">@Override</span>
+ <span class="kd">public</span> <span class="kt">void</span> <span
class="nf">register</span><span class="o">(</span><span
class="n">ContainerBuilder</span> <span class="n">builder</span><span
class="o">,</span> <span class="n">LocatableProperties</span> <span
class="n">props</span><span class="o">)</span> <span class="kd">throws</span>
<span class="n">ConfigurationException</span> <span class="o">{</span>
+ <span class="n">alias</span><span class="o">(</span><span
class="n">VelocityManager</span><span class="o">.</span><span
class="na">class</span><span class="o">,</span> <span
class="n">VelocityConstants</span><span class="o">.</span><span
class="na">STRUTS_VELOCITY_MANAGER_CLASSNAME</span><span class="o">,</span>
<span class="n">builder</span><span class="o">,</span> <span
class="n">props</span><span class="o">);</span>
+ <span class="o">}</span>
+
+<span class="o">}</span>
+</code></pre></div></div>
+
+<p>The class defines extension points by implementing <code
class="highlighter-rouge">register()</code> method and using <code
class="highlighter-rouge">alias()</code> method to register them.</p>
+
+<p>And finally it must be added to the <code
class="highlighter-rouge">struts-plugin.xml</code>:</p>
+
+<div class="language-xml highlighter-rouge"><div class="highlight"><pre
class="highlight"><code><span class="cp"><?xml version="1.0"
encoding="UTF-8" ?></span>
+<span class="cp"><!DOCTYPE struts PUBLIC
+ "-//Apache Software Foundation//DTD Struts Configuration 2.6//EN"
+ "http://struts.apache.org/dtds/struts-2.6.dtd"></span>
+
+<span class="nt"><struts></span>
+ ...
+
+ <span class="nt"><bean-selection</span> <span
class="na">name=</span><span class="s">"velocityBeans"</span> <span
class="na">class=</span><span
class="s">"org.apache.struts2.views.velocity.VelocityBeanSelectionProvider"</span><span
class="nt">/></span>
+
+<span class="nt"></struts></span>
+</code></pre></div></div>
+
+<p>And now other plugins or user application can use the new extension point
represented by <code
class="highlighter-rouge">VelocityConstants.STRUTS_VELOCITY_MANAGER_CLASSNAME</code>.</p>
+
+<h2 id="plugin-registry">Plugin Registry</h2>
+
+<blockquote>
+ <p>For a list of bundled plugins, see the <a href="index">Plugin Reference
Documentation</a>. For more about bundled and third-party
+plugins, visit the <a href="http://cwiki.apache.org/S2PLUGINS/home";>Apache
Struts Plugin Registry</a>.</p>
+</blockquote>
+
+ </section>
+</article>
+
+
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