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Posted to dev@tapestry.apache.org by bu...@apache.org on 2014/12/15 19:20:07 UTC
svn commit: r932865 - in /websites/production/tapestry/content:
cache/main.pageCache component-parameters.html session-storage.html
Author: buildbot
Date: Mon Dec 15 18:20:06 2014
New Revision: 932865
Log:
Production update by buildbot for tapestry
Modified:
websites/production/tapestry/content/cache/main.pageCache
websites/production/tapestry/content/component-parameters.html
websites/production/tapestry/content/session-storage.html
Modified: websites/production/tapestry/content/cache/main.pageCache
==============================================================================
Binary files - no diff available.
Modified: websites/production/tapestry/content/component-parameters.html
==============================================================================
--- websites/production/tapestry/content/component-parameters.html (original)
+++ websites/production/tapestry/content/component-parameters.html Mon Dec 15 18:20:06 2014
@@ -66,8 +66,7 @@
</div>
<div id="content">
-<div id="ConfluenceContent"><div class="navmenu" style="float:right; background:white; margin:3px; padding:3px">
-<div class="panel" style="border-width: 1px;"><div class="panelContent">
+<div id="ConfluenceContent"><div class="navmenu" style="float:right; background:#eee; margin:3px; padding:3px">
<h3>Related Articles</h3>
<ul class="content-by-label"><li>
<div>
@@ -151,27 +150,21 @@
</div>
</li></ul>
-</div></div>
-
-<h3><a shape="rect" name="ComponentParameters-Contents"></a>Contents</h3>
-<style type="text/css">/*<![CDATA[*/
-div.rbtoc1418660381193 {padding: 0px;}
-div.rbtoc1418660381193 ul {list-style: disc;margin-left: 0px;}
-div.rbtoc1418660381193 li {margin-left: 0px;padding-left: 0px;}
-
-/*]]>*/</style><div class="toc-macro rbtoc1418660381193">
-<ul class="toc-indentation"><li>Related Articles</li><li><a shape="rect" href="#ComponentParameters-Contents">Contents</a></li></ul>
-<ul><li><a shape="rect" href="#ComponentParameters-ParameterBindings">Parameter Bindings</a></li><li><a shape="rect" href="#ComponentParameters-BindingExpressions">Binding Expressions</a>
-<ul class="toc-indentation"><li><a shape="rect" href="#ComponentParameters-RenderVariables:Bindings">Render Variables: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Property:Bindings">Property: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Validate:Bindings">Validate: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Translate:Bindings">Translate: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Asset:Bindings">Asset: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Context:Bindings">Context: Bindings</a></li></ul>
-</li><li><a shape="rect" href="#ComponentParameters-@Parameterannotation">@Parameter annotation</a>
-<ul class="toc-indentation"><li><a shape="rect" href="#ComponentParameters-RequiredParameters">Required Parameters</a></li><li><a shape="rect" href="#ComponentParameters-OptionalParameters">Optional Parameters</a></li><li><a shape="rect" href="#ComponentParameters-ParameterBindingDefaults">Parameter Binding Defaults</a></li><li><a shape="rect" href="#ComponentParameters-ParameterCaching">Parameter Caching</a></li></ul>
-</li><li><a shape="rect" href="#ComponentParameters-Don'tusethe${...}syntax!">Don't use the ${...} syntax!</a></li><li><a shape="rect" href="#ComponentParameters-InformalParameters">Informal Parameters</a></li><li><a shape="rect" href="#ComponentParameters-ParametersAreBi-Directional">Parameters Are Bi-Directional</a></li><li><a shape="rect" href="#ComponentParameters-InheritedParameterBindings">Inherited Parameter Bindings</a></li><li><a shape="rect" href="#ComponentParameters-ComputedParameterBindingDefaults">Computed Parameter Binding Defaults</a></li><li><a shape="rect" href="#ComponentParameters-UnboundParameters">Unbound Parameters</a></li><li><a shape="rect" href="#ComponentParameters-ParameterTypeCoercion">Parameter Type Coercion</a></li><li><a shape="rect" href="#ComponentParameters-ParameterNames">Parameter Names</a></li><li><a shape="rect" href="#ComponentParameters-DeterminingifBound">Determining if Bound</a></li><li><a shape="rect" href="#ComponentParameters-PublishingP
arameters">Publishing Parameters</a></li></ul>
-</div></div><p><strong>Component parameters</strong> are the primary means for a component instance and its container to communicate with each other. Parameters are used to <em>configure</em> component instances.</p><p>In the following example, <code>page</code> is a parameter of the <code>pagelink</code> component. The page parameter tells the pagelink component which page to go to when the user clicks on the rendered hyperlink:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+</div><p><strong>Component parameters</strong> are the primary means for a component instance and its container to communicate with each other. Parameters are used to <em>configure</em> component instances.</p><p>In the following example, <code>page</code> is a parameter of the <code>pagelink</code> component. The page parameter tells the pagelink component which page to go to when the user clicks on the rendered hyperlink:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
<script class="theme: Default; brush: xml; gutter: false" type="syntaxhighlighter"><![CDATA[<html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_3.xsd">
<t:pagelink page="Index">Go Home</t:pagelink>
-</html>
-]]></script>
-</div></div><p>A component may have any number of parameters. Each parameter has a specific name, a specific Java type (which may be a primitive value), and may be <em>optional</em> or <em>required</em>.</p><p>Within a component class, parameters are declared by using the @<a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Parameter.html">Parameter</a> annotation on a private field, as we'll see below.</p><p><span class="confluence-anchor-link" id="ComponentParameters-bindingparameters"></span></p><h1 id="ComponentParameters-ParameterBindings">Parameter Bindings</h1><p>In Tapestry, a parameter is not a slot into which data is pushed: it is a <em>connection</em> between a field of the component (marked with the @Parameter annotation) and a property or resource of the component's container. (Components can be nested, so the container can be either the page or another component.)</p><p>The connection between a compone
nt and a property (or resource) of its container is called a <em>binding</em>. The binding is two-way: the component can read the bound property by reading its parameter field. Likewise, a component that updates its parameter field will update the bound property.</p><p>This is important in a lot of cases; for example a TextField component can read <em>and update</em> the property bound to its value parameter. It reads the value when rendering, but updates the value when the form is submitted.</p><p>The component listed below is a looping component; it renders its body a number of times, defined by its <code>start</code> and <code>end</code> parameters (which set the boundaries of the loop). The component can update a <code>result</code> parameter bound to a property of its container; it will automatically count up or down depending on whether <code>start</code> or <code>end</code> is larger.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelConte
nt pdl">
+</html>]]></script>
+</div></div><p>A component may have any number of parameters. Each parameter has a specific name, a specific Java type (which may be a primitive value), and may be <em>optional</em> or <em>required</em>.</p><p>Within a component class, parameters are declared by using the @<a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Parameter.html">Parameter</a> annotation on a private field, as we'll see below.</p><p><span class="confluence-anchor-link" id="ComponentParameters-bindingparameters"></span></p><h1 id="ComponentParameters-ParameterBindings">Parameter Bindings</h1><p>In Tapestry, a parameter is not a slot into which data is pushed: it is a <em>connection</em> between a field of the component (marked with the @Parameter annotation) and a property or resource of the component's container. (Components can be nested, so the container can be either the page or another component.)</p><div class="navmenu" style="float:r
ight; background:white; margin:3px; padding:3px">
+<div class="panel" style="border-width: 1px;"><div class="panelHeader" style="border-bottom-width: 1px;"><b>Contents</b></div><div class="panelContent">
+<style type="text/css">/*<![CDATA[*/
+div.rbtoc1418667590913 {padding: 0px;}
+div.rbtoc1418667590913 ul {list-style: disc;margin-left: 0px;}
+div.rbtoc1418667590913 li {margin-left: 0px;padding-left: 0px;}
+
+/*]]>*/</style><div class="toc-macro rbtoc1418667590913">
+<ul class="toc-indentation"><li>Related Articles</li><li><a shape="rect" href="#ComponentParameters-RenderVariables:Bindings">Render Variables: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Property:Bindings">Property: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Validate:Bindings">Validate: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Translate:Bindings">Translate: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Asset:Bindings">Asset: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-Context:Bindings">Context: Bindings</a></li><li><a shape="rect" href="#ComponentParameters-RequiredParameters">Required Parameters</a></li><li><a shape="rect" href="#ComponentParameters-OptionalParameters">Optional Parameters</a></li><li><a shape="rect" href="#ComponentParameters-ParameterBindingDefaults">Parameter Binding Defaults</a></li><li><a shape="rect" href="#ComponentParameters-ParameterCaching">Parameter Cach
ing</a></li></ul>
+</div>
+</div></div></div><p> </p><p>The connection between a component and a property (or resource) of its container is called a <em>binding</em>. The binding is two-way: the component can read the bound property by reading its parameter field. Likewise, a component that updates its parameter field will update the bound property.</p><p>This is important in a lot of cases; for example a TextField component can read <em>and update</em> the property bound to its value parameter. It reads the value when rendering, but updates the value when the form is submitted.</p><p>The component listed below is a looping component; it renders its body a number of times, defined by its <code>start</code> and <code>end</code> parameters (which set the boundaries of the loop). The component can update a <code>result</code> parameter bound to a property of its container; it will automatically count up or down depending on whether <code>start</code> or <code>end</code> is larger.</p><div class="code panel
pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[package org.example.app.components;
import org.apache.tapestry5.annotations.AfterRender;
Modified: websites/production/tapestry/content/session-storage.html
==============================================================================
--- websites/production/tapestry/content/session-storage.html (original)
+++ websites/production/tapestry/content/session-storage.html Mon Dec 15 18:20:06 2014
@@ -66,7 +66,7 @@
</div>
<div id="content">
-<div id="ConfluenceContent"><div class="navmenu" style="float:right; background:#eee; margin:3px; padding:3px">
+<div id="ConfluenceContent"><p> </p><p>Most web applications will need to have some data that is shared across multiple pages. Perhaps you are creating a multi-page wizard, or you have an object that tracks the user's identify once logged in, or maybe you need to manage a shopping cart.</p><div class="navmenu" style="float:right; background:#eee; margin:3px; padding:3px">
<h3>Related Articles</h3>
<ul class="content-by-label"><li>
<div>
@@ -82,7 +82,7 @@
<span class="icon icon-page" title="Page">Page:</span> </div>
<div class="details">
- <a shape="rect" href="session-storage.html">Session Storage</a>
+ <a shape="rect" href="performance-and-clustering.html">Performance and Clustering</a>
</div>
@@ -91,22 +91,21 @@
<span class="icon icon-page" title="Page">Page:</span> </div>
<div class="details">
- <a shape="rect" href="performance-and-clustering.html">Performance and Clustering</a>
+ <a shape="rect" href="session-storage.html">Session Storage</a>
</div>
</li></ul>
-</div>
-
-<h1 id="SessionStorage-SessionStorage">Session Storage</h1>
-
+</div><p>Ordinary <a shape="rect" href="persistent-page-data.html">page-persistent fields</a> won't work for this, since persistent fields are available only to a specific page, not shared across multiple pages.</p><p>Tapestry provides two mechanisms for storing such data: Session State Objects and Session Attributes. When deciding between the two, it's best to use Session State Objects for complex objects, and Session Attributes for simple types.</p><h2 id="SessionStorage-SessionStateObjects">Session State Objects</h2><p>With a Session State Object (SSO), the value is automatically stored outside the page; with the default storage strategy, it is stored in the session. Such a value is global to all pages <em>for the same user</em>, but is stored separately for different users.</p><p>A field holding an SSO is marked with the @<a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/SessionState.html">SessionState</a> ann
otation.</p><div class="navmenu" style="float:right; background:white; margin:3px; padding:3px">
+<div class="panel" style="border-width: 1px;"><div class="panelHeader" style="border-bottom-width: 1px;"><b>Contents</b></div><div class="panelContent">
<style type="text/css">/*<![CDATA[*/
-div.rbtoc1418617265504 {padding: 0px;}
-div.rbtoc1418617265504 ul {list-style: disc;margin-left: 0px;}
-div.rbtoc1418617265504 li {margin-left: 0px;padding-left: 0px;}
-
-/*]]>*/</style><div class="toc-macro rbtoc1418617265504">
-<ul class="toc-indentation"><li>Related Articles</li><li><a shape="rect" href="#SessionStorage-SessionStateObjects">Session State Objects</a>
+div.rbtoc1418667592882 {padding: 0px;}
+div.rbtoc1418667592882 ul {list-style: disc;margin-left: 0px;}
+div.rbtoc1418667592882 li {margin-left: 0px;padding-left: 0px;}
+
+/*]]>*/</style><div class="toc-macro rbtoc1418667592882">
+<ul class="toc-indentation"><li>Related Articles</li></ul>
+<ul><li><a shape="rect" href="#SessionStorage-SessionStateObjects">Session State Objects</a>
<ul class="toc-indentation"><li><a shape="rect" href="#SessionStorage-Pitfalls">Pitfalls</a></li><li><a shape="rect" href="#SessionStorage-CheckforCreation">Check for Creation</a></li><li><a shape="rect" href="#SessionStorage-PersistenceStrategies">Persistence Strategies</a></li><li><a shape="rect" href="#SessionStorage-ConfiguringSSOs">Configuring SSOs</a></li></ul>
</li><li><a shape="rect" href="#SessionStorage-SessionAttributes">Session Attributes</a>
<ul class="toc-indentation"><li><a shape="rect" href="#SessionStorage-Pitfalls.1">Pitfalls</a></li></ul>
@@ -114,24 +113,8 @@ div.rbtoc1418617265504 li {margin-left:
<ul class="toc-indentation"><li><a shape="rect" href="#SessionStorage-@ImmutableSessionPersistedObjectAnnotation">@ImmutableSessionPersistedObject Annotation</a></li><li><a shape="rect" href="#SessionStorage-OptimizedSessionPersistedObjectInterface">OptimizedSessionPersistedObject Interface</a></li><li><a shape="rect" href="#SessionStorage-SessionPersistedObjectAnalyzerService">SessionPersistedObjectAnalyzer Service</a></li></ul>
</li><li><a shape="rect" href="#SessionStorage-SessionLocking">Session Locking</a></li></ul>
</div>
-
-<p>Most web applications will need to have some data that is shared across multiple pages. Perhaps you are creating a multi-page wizard, or you have an object that tracks the user's identify once logged in, or maybe you need to manage a shopping cart.</p>
-
-<p>Ordinary <a shape="rect" href="persistent-page-data.html">page-persistent fields</a> won't work for this, since persistent fields are available only to a specific page, not shared across multiple pages.</p>
-
-<p>Tapestry provides two mechanisms for storing such data: Session State Objects and Session Attributes. When deciding between the two, it's best to use Session State Objects for complex objects, and Session Attributes for simple types.</p>
-
-<h2 id="SessionStorage-SessionStateObjects">Session State Objects</h2>
-
-<p>With a Session State Object (SSO), the value is automatically stored outside the page; with the default storage strategy, it is stored in the session. Such a value is global to all pages <em>for the same user</em>, but is stored separately for different users.</p>
-
-<p>A field holding an SSO is marked with the @<a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/SessionState.html">SessionState</a> annotation.</p>
-
-<p>Example:</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
-public class MyPage
+</div></div></div><p>Example:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[public class MyPage
{
@SessionState
private ShoppingCart shoppingCart;
@@ -139,32 +122,14 @@ public class MyPage
. . .
}
]]></script>
-</div></div>
-
-<p>Any other component or page that declares a field <strong>of the same type</strong>, regardless of name, and marks it with the SessionState annotation will share the same value. It's that simple. However, using @SessionState <em>safely</em> requires care:</p>
-
- <div class="aui-message problem shadowed information-macro">
+</div></div><p>Any other component or page that declares a field <strong>of the same type</strong>, regardless of name, and marks it with the SessionState annotation will share the same value. It's that simple. However, using @SessionState <em>safely</em> requires care:</p> <div class="aui-message problem shadowed information-macro">
<span class="aui-icon icon-problem">Icon</span>
<div class="message-content">
-
-<p>DO NOT USE @SessionState FOR SIMPLE TYPES! Only use it on variables that are of a custom-built class designed expressly for this purpose! <strong>See the Pitfalls section below</strong>.</p>
+ <p>DO NOT USE @SessionState FOR SIMPLE TYPES! Only use it on variables that are of a custom-built class designed expressly for this purpose! <strong>See the Pitfalls section below</strong>.</p>
</div>
</div>
-
-
-<p>The first time you access an SSO, it is created automatically. Typically, the SSO will have a public no-args constructor ... but you may inject dependencies into the SSO via its constructor, as you can with a Tapestry IoC service implementation.</p>
-
-<p><em>For Tapestry 4 Users:</em> a big change here is that you don't need to provide any configuration for the SSO before using it, nor do you provide a logical name. Tapestry 5 uses the class name to identify the SSO, so there's no need for a logical name.</p>
-
-<p>Assigning a value to an SSO field will store that value. Assigning null to an SSO field will remove the SSO (reading the field subsequently will force a new SSO instance to be created).</p>
-
-<h3 id="SessionStorage-Pitfalls">Pitfalls</h3>
-
-<p>With @SessionState, you are creating a session-wide data storage area that is tied to the <em>type</em> (class) of the variable you annotate. It is not specifically tied to the variable itself, or even to the class in which that variable was annotated. As with all session data, there is the serious possibility of collisions, not just within your application but with other modules/libraries:</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>Example of Data Collision – Don't Do This!</b></div><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
- @SessionState
+<p>The first time you access an SSO, it is created automatically. Typically, the SSO will have a public no-args constructor ... but you may inject dependencies into the SSO via its constructor, as you can with a Tapestry IoC service implementation.</p><p><em>For Tapestry 4 Users:</em> a big change here is that you don't need to provide any configuration for the SSO before using it, nor do you provide a logical name. Tapestry 5 uses the class name to identify the SSO, so there's no need for a logical name.</p><p>Assigning a value to an SSO field will store that value. Assigning null to an SSO field will remove the SSO (reading the field subsequently will force a new SSO instance to be created).</p><h3 id="SessionStorage-Pitfalls">Pitfalls</h3><p>With @SessionState, you are creating a session-wide data storage area that is tied to the <em>type</em> (class) of the variable you annotate. It is not specifically tied to the variable itself, or even to the class in which that variable was
annotated. As with all session data, there is the serious possibility of collisions, not just within your application but with other modules/libraries:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>Example of Data Collision – Don't Do This!</b></div><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[ @SessionState
private String userName; // Unsafe -- String is not a custom type
... then, later in this class or any other:
@@ -172,54 +137,15 @@ public class MyPage
@sessionState
private String userCity; // This overwrites value in userName, because it's also a String!
]]></script>
-</div></div>
-
-<p>The simple rule is, NEVER use @SessionState for simple-type variables. It is ALWAYS worth taking the time to build a special class to hold your session state information. Doing so will force you to consolidate that information into a single, logical unit that can't be accidentally accessed by other classes. (Alternatively, see the Session Attribute section below.)</p>
-
-<h3 id="SessionStorage-CheckforCreation">Check for Creation</h3>
-
-<p>Scalable web applications do not create the server-side session needlessly. If you can avoid creating the session, especially on first access to your web application, you will be able to handle an order of magnitude more users. So, if you can avoid creating the SSO, you should do so.</p>
-
-<p>But how to avoid creating it? Simply checking ("shoppingCart!= null") will force the creation of the SSO and the session to store it in.</p>
-
-<p>Instead, create a second field with a matching name but with "Exists" appended:</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
- private boolean shoppingCartExists;
+</div></div><p>The simple rule is, NEVER use @SessionState for simple-type variables. It is ALWAYS worth taking the time to build a special class to hold your session state information. Doing so will force you to consolidate that information into a single, logical unit that can't be accidentally accessed by other classes. (Alternatively, see the Session Attribute section below.)</p><h3 id="SessionStorage-CheckforCreation">Check for Creation</h3><p>Scalable web applications do not create the server-side session needlessly. If you can avoid creating the session, especially on first access to your web application, you will be able to handle an order of magnitude more users. So, if you can avoid creating the SSO, you should do so.</p><p>But how to avoid creating it? Simply checking ("shoppingCart!= null") will force the creation of the SSO and the session to store it in.</p><p>Instead, create a second field with a matching name but with "Exists" appended:</p><div class="code panel pdl"
style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[ private boolean shoppingCartExists;
]]></script>
-</div></div>
-
-<p>It is not annotated; it is located by naming convention ("Exists" appended). It must be type boolean and must be a private instance variable. Tapestry will automatically set this variable to <code>true</code> when the SSO is created, so you can check it to see if the SSO already exists.</p>
-
-<p>Alternately, you may allow for the state being null:</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
- @SessionState(create=false)
+</div></div><p>It is not annotated; it is located by naming convention ("Exists" appended). It must be type boolean and must be a private instance variable. Tapestry will automatically set this variable to <code>true</code> when the SSO is created, so you can check it to see if the SSO already exists.</p><p>Alternately, you may allow for the state being null:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[ @SessionState(create=false)
private ShoppingCart shoppingCart;
]]></script>
-</div></div>
-
-<p>In this case, the shoppingCart field will be null if the ShoppingCart SSO does not exist, but will be non-null if it has been created (either by assigning a value to the field, or by a different SSO field where create is true).</p>
-
-<h3 id="SessionStorage-PersistenceStrategies">Persistence Strategies</h3>
-
-<p>Main Article: <a shape="rect" href="persistent-page-data.html#PersistentPageData-PersistenceStrategies">Persistent Page Data</a></p>
-
-<p>Each SSO is managed according to a persistence strategy. The default persistence strategy, "session", stores the SSOs inside the session. The session is created as needed.</p>
-
-<h3 id="SessionStorage-ConfiguringSSOs">Configuring SSOs</h3>
-
-<p>Generally, you will need to configure your Session State Object if you want to change the persistence strategy to other than the default. (Right now there's only one built in strategy, but more will be coming in the future.)</p>
-
-<p>Alternately, you can configure a Session State Object in order to control how it is instantiated. You may need to inject some values into the SSO when it is first created, or otherwise initialize it. In this case, you may provide an <a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/ApplicationStateCreator.html">ApplicationStateCreator</a> object, which will be called upon to create the SSO as necessary. This is also the technique to use when you want your SSO to be represented by an <em>interface</em> rather than a <em>class</em>: you need to provide a creator that knows about the class that implements the interface.</p>
-
-<p>A Session State Object is configured using contributions to the ApplicationStateManager service. From your application's module:</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
- public void contributeApplicationStateManager(MappedConfiguration<Class, ApplicationStateContribution> configuration)
+</div></div><p>In this case, the shoppingCart field will be null if the ShoppingCart SSO does not exist, but will be non-null if it has been created (either by assigning a value to the field, or by a different SSO field where create is true).</p><h3 id="SessionStorage-PersistenceStrategies">Persistence Strategies</h3><p>Main Article: <a shape="rect" href="persistent-page-data.html#PersistentPageData-PersistenceStrategies">Persistent Page Data</a></p><p>Each SSO is managed according to a persistence strategy. The default persistence strategy, "session", stores the SSOs inside the session. The session is created as needed.</p><h3 id="SessionStorage-ConfiguringSSOs">Configuring SSOs</h3><p>Generally, you will need to configure your Session State Object if you want to change the persistence strategy to other than the default. (Right now there's only one built in strategy, but more will be coming in the future.)</p><p>Alternately, you can configure a Session State Object in order to cont
rol how it is instantiated. You may need to inject some values into the SSO when it is first created, or otherwise initialize it. In this case, you may provide an <a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/ApplicationStateCreator.html">ApplicationStateCreator</a> object, which will be called upon to create the SSO as necessary. This is also the technique to use when you want your SSO to be represented by an <em>interface</em> rather than a <em>class</em>: you need to provide a creator that knows about the class that implements the interface.</p><p>A Session State Object is configured using contributions to the ApplicationStateManager service. From your application's module:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[ public void contributeApplicationStateManager(MappedConfiguration<Class, ApplicationStateContribution> configuration)
{
ApplicationStateCreator<MyState> creator = new ApplicationStateCreator<ShoppingCart>()
{
@@ -232,19 +158,7 @@ public class MyPage
configuration.add(ShoppingCart.class, new ApplicationStateContribution("session", creator));
}
]]></script>
-</div></div>
-
-<p>Here, we have an SSO type of ShoppingCart, and we're providing a creator for it. We've dolled the creator up with some generic types, but that isn't essential.</p>
-
-<p>Our creator creates a new MyState instance using an alternate constructor that takes the current date and time. Again, just an example.</p>
-
-<p>Finally, we create an <a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/ApplicationStateContribution.html">ApplicationStateContribution</a> identifying the strategy name and the creator, and give that to the configuration.</p>
-
-<p><strong>Note:</strong> You might be confused by the name "_Application_StateManager" and "_Application_StateCreator"; these reflect a difference in naming between 5.0 and 5.1; SSOs were originally called "Application State Objects", but that naming implied they were stored in the ServletContext, as application global to all users. The new SessionState annotation was introduced, but the existing services need to keep thier names as-is.</p>
-
-<h2 id="SessionStorage-SessionAttributes">Session Attributes</h2>
-
-
+</div></div><p>Here, we have an SSO type of ShoppingCart, and we're providing a creator for it. We've dolled the creator up with some generic types, but that isn't essential.</p><p>Our creator creates a new MyState instance using an alternate constructor that takes the current date and time. Again, just an example.</p><p>Finally, we create an <a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/ApplicationStateContribution.html">ApplicationStateContribution</a> identifying the strategy name and the creator, and give that to the configuration.</p><p><strong>Note:</strong> You might be confused by the name "_Application_StateManager" and "_Application_StateCreator"; these reflect a difference in naming between 5.0 and 5.1; SSOs were originally called "Application State Objects", but that naming implied they were stored in the ServletContext, as application global to all users. The new SessionState annotation was introduce
d, but the existing services need to keep thier names as-is.</p><h2 id="SessionStorage-SessionAttributes">Session Attributes</h2>
<div class="aui-message hint shadowed information-macro">
<p class="title">Added in 5.2</p>
@@ -256,13 +170,8 @@ public class MyPage
</div>
<div style="border-right: 20px solid #D8E4F1;border-left: 20px solid #D8E4F1;">
-</div>
-
-<p>As an alternative to SSOs, Tapestry provides a <strong>Session Attribute</strong> mechanism, which lets you store data in the session by name (rather than type). It is particularly useful when integrating Tapestry with legacy applications that directly manipulate the HttpSession.</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>The Old Way</b></div><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
-public class Page {
+<p> </p></div><p>As an alternative to SSOs, Tapestry provides a <strong>Session Attribute</strong> mechanism, which lets you store data in the session by name (rather than type). It is particularly useful when integrating Tapestry with legacy applications that directly manipulate the HttpSession.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>The Old Way</b></div><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[public class Page {
@Inject
private Request request;
@@ -271,40 +180,20 @@ public class Page {
}
}
]]></script>
-</div></div>
-
-<p>Starting with Tapestry 5.2, this can be accomplished just by annotating a page or component property with @<a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/SessionAttribute.html">SessionAttribute</a>. This annotation is used to map a property of a page or component to value stored in session. Unlike Session State Objects, the name (not the type) of the annotated property is used as the name of the session attribute to look for.</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>The New Way</b></div><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
-public class Page {
+</div></div><p>Starting with Tapestry 5.2, this can be accomplished just by annotating a page or component property with @<a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/SessionAttribute.html">SessionAttribute</a>. This annotation is used to map a property of a page or component to value stored in session. Unlike Session State Objects, the name (not the type) of the annotated property is used as the name of the session attribute to look for.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>The New Way</b></div><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[public class Page {
@SessionAttribute
private User loggedInUserName;
}
]]></script>
-</div></div>
-
-<p>You can also provide a name using the annotation's <code>value</code> parameter:</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
-public class Page {
+</div></div><p>You can also provide a name using the annotation's <code>value</code> parameter:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[public class Page {
@SessionAttribute("loggedInUserName")
private User userName;
}
]]></script>
-</div></div>
-
-
-<h3 id="SessionStorage-Pitfalls.1">Pitfalls</h3>
-
-<p>As with SSOs, when using Session Attributes you are creating a session-wide data storage area that has the serious possibility of data collisions, not just within your application but with other modules/libraries. To avoid problems, you should qualify the session attribute name with a package-like naming convention. For example, use something like "com.mycompany.myapp.username" instead of just "username".</p>
-
-<p>It's best to define the session attribute name as constant, and use that in the annotation's value parameter, rather then defaulting to the instance variable name. This will help prevent subtle runtime errors due to misspellings. For example:</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>The Safer Way</b></div><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
-public static final String USER_NAME_SESSION_ATTRIBUTE = "com.example.shoppingapp.username";
+</div></div><h3 id="SessionStorage-Pitfalls.1">Pitfalls</h3><p>As with SSOs, when using Session Attributes you are creating a session-wide data storage area that has the serious possibility of data collisions, not just within your application but with other modules/libraries. To avoid problems, you should qualify the session attribute name with a package-like naming convention. For example, use something like "com.mycompany.myapp.username" instead of just "username".</p><p>It's best to define the session attribute name as constant, and use that in the annotation's value parameter, rather then defaulting to the instance variable name. This will help prevent subtle runtime errors due to misspellings. For example:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>The Safer Way</b></div><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[public static final String USER_NAME_SESSION_ATTRIBUTE = "com.example.shoppingapp.username";
...
@@ -313,9 +202,7 @@ public class Page {
private User userName;
}
]]></script>
-</div></div>
-
-<h2 id="SessionStorage-ClusteringIssues">Clustering Issues</h2>
+</div></div><p></p><h2 id="SessionStorage-ClusteringIssues">Clustering Issues</h2>
<p>The Servlet API was designed with the intention that there would be only a modest amount of server-side state, and that the stored values would be individual numbers and strings, and thus, immutable.</p>
@@ -341,18 +228,8 @@ public class Page {
<h3 id="SessionStorage-SessionPersistedObjectAnalyzerService">SessionPersistedObjectAnalyzer Service</h3>
-<p>The <a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/SessionPersistedObjectAnalyzer.html">SessionPersistedObjectAnalyzer</a> service is ultimately responsible for determining whether a session persisted object is dirty or not (dirty meaning in need of a restore into the session). This is an extensible service where new strategies, for new classes, can be introduced.</p>
-
-<h2 id="SessionStorage-SessionLocking">Session Locking</h2>
-
-<p>Starting with version 5.4, by default Tapestry will apply locking semantics around access to the HttpSession. Reading attribute names occurs with a shared read lock, and getting or setting an attribute upgrades the lock to an exclusive write lock. This can tend to serialize threads when a number of simultaneous (Ajax) requests from the client arrive. However, many implementations of HttpSession are not thread safe, and often mutable objects<br clear="none">
-are stored in the session and shared between threads.</p>
-
-<p>The <code>tapestry.session-locking-enabled</code> <a shape="rect" href="configuration.html">symbol</a> can control this behavior. Setting this to true (the default) will yield a more robust application; setting it to false may speed up processing for more Ajax intensive applications (but care should then be given to ensuring that objects shared inside the session are themeselves immutable or thread-safe).</p>
-
-<div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>AppModule.java (partial)</b></div><div class="codeContent panelContent pdl">
-<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[
- public static void contributeApplicationDefaults(MappedConfiguration<String,String> configuration)
+<p>The <a shape="rect" class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/SessionPersistedObjectAnalyzer.html">SessionPersistedObjectAnalyzer</a> service is ultimately responsible for determining whether a session persisted object is dirty or not (dirty meaning in need of a restore into the session). This is an extensible service where new strategies, for new classes, can be introduced.</p><h2 id="SessionStorage-SessionLocking">Session Locking</h2><p>Starting with version 5.4, by default Tapestry will apply locking semantics around access to the HttpSession. Reading attribute names occurs with a shared read lock, and getting or setting an attribute upgrades the lock to an exclusive write lock. This can tend to serialize threads when a number of simultaneous (Ajax) requests from the client arrive. However, many implementations of HttpSession are not thread safe, and often mutable objects<br clear="none"> are stored in the session and
shared between threads.</p><p>The <code>tapestry.session-locking-enabled</code> <a shape="rect" href="configuration.html">symbol</a> can control this behavior. Setting this to true (the default) will yield a more robust application; setting it to false may speed up processing for more Ajax intensive applications (but care should then be given to ensuring that objects shared inside the session are themeselves immutable or thread-safe).</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>AppModule.java (partial)</b></div><div class="codeContent panelContent pdl">
+<script class="theme: Default; brush: java; gutter: false" type="syntaxhighlighter"><![CDATA[ public static void contributeApplicationDefaults(MappedConfiguration<String,String> configuration)
{
configuration.add(SymbolConstants.SESSION_LOCKING_ENABLED, true);
...