Modified: websites/production/tapestry/content/component-cheat-sheet.html
==============================================================================
--- websites/production/tapestry/content/component-cheat-sheet.html (original)
+++ websites/production/tapestry/content/component-cheat-sheet.html Wed Sep 20
12:29:16 2017
@@ -27,6 +27,14 @@
</title>
<link type="text/css" rel="stylesheet" href="/resources/space.css" />
+ <link href='/resources/highlighter/styles/shCoreCXF.css'
rel='stylesheet' type='text/css' />
+ <link href='/resources/highlighter/styles/shThemeCXF.css' rel='stylesheet'
type='text/css' />
+ <script src='/resources/highlighter/scripts/shCore.js'
type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushJava.js'
type='text/javascript'></script>
+ <script>
+ SyntaxHighlighter.defaults['toolbar'] = false;
+ SyntaxHighlighter.all();
+ </script>
<link href="/styles/style.css" rel="stylesheet" type="text/css"/>
@@ -36,26 +44,13 @@
<div class="wrapper bs">
- <div id="navigation"><div class="nav"><ul class="alternate"><li><a
href="index.html">Home</a></li><li><a href="getting-started.html">Getting
Started</a></li><li><a href="documentation.html">Documentation</a></li><li><a
href="download.html">Download</a></li><li><a
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href="http://www.apache.org/licenses/LICENSE-2.0";>License</a></li><li><a
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href="http://www.apache.org/security/";>Security</a></li><li><a
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class="external-link"
href="http://www.apache.org/foundation/sponsorship.html";>Sponsorship</a></li><li><a
class="external-link"
href="http://www.apache.org/foundation/thanks.html";>Thanks</a></li></ul></div>
-
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+ <div id="navigation"><div class="nav"><ul class="alternate"><li><a
href="index.html">Home</a></li><li><a href="getting-started.html">Getting
Started</a></li><li><a href="documentation.html">Documentation</a></li><li><a
href="download.html">Download</a></li><li><a
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href="http://www.apache.org/foundation/thanks.html";>Thanks</a></li></ul></div></div>
<div id="top">
- <div id="smallbanner"><div class="searchbox"
style="float:right;margin: .3em 1em .1em 1em"><span style="color: #999;
font-size: 90%">Tapestry docs, issues, wikis & blogs:</span>
-<form enctype="application/x-www-form-urlencoded" method="get"
action="http://tapestry.apache.org/search.html";>
- <input type="text" name="q">
- <input type="submit" value="Search">
-</form>
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-
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-<div class="emblem" style="float:left"><p><a href="index.html"><span
class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image
confluence-external-resource"
src="http://tapestry.apache.org/images/tapestry_small.png";
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-
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-<div class="title" style="float:left; margin: 0 0 0 3em"><h1
id="SmallBanner-PageTitle">Component Cheat Sheet</h1></div>
-
-</div>
+ <div id="smallbanner"><div class="searchbox"
style="float:right;margin: .3em 1em .1em 1em"><span style="color: #999;
font-size: 90%">Tapestry docs, issues, wikis & blogs:</span><form
enctype="application/x-www-form-urlencoded" method="get"
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+ <input type="text" name="q">
+ <input type="submit" value="Search">
+</form></div><div class="emblem" style="float:left"><p><a
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class="title" style="float:left; margin: 0 0 0 3em"><h1
id="SmallBanner-PageTitle">Component Cheat Sheet</h1></div></div>
<div class="clearer"></div>
</div>
@@ -67,15 +62,67 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><p><parameter
ac:name="hidden">true</parameter><parameter
ac:name="atlassian-macro-output-type">INLINE</parameter><rich-text-body><p>the
various annotations and methods you can add to Tapestry page and component
classes</p></rich-text-body></p><p> </p><p>This is a summary of the more
common annotations and methods you can add to Tapestry pages and component
classes.</p><parameter ac:name="style">float:right</parameter><parameter
ac:name="title">Related Articles</parameter><parameter
ac:name="class">aui-label</parameter><rich-text-body><parameter
ac:name="showLabels">false</parameter><parameter
ac:name="showSpace">false</parameter><parameter ac:name="title">Related
Articles</parameter><parameter ac:name="cql">label in
("component-classes","component-templates","components") and space =
currentSpace()</parameter></rich-text-body><p>For an exhaustive list, see the
<a href="annotations.html">annotations list</a>.</p><h2 id="ComponentChea
tSheet-FieldInjectionAnnotations">Field Injection Annotations</h2><p>Main
articles: <a href="component-classes.html">Component Classes</a>, <a
href="injection.html">Injection</a>, <a
href="annotations.html">Annotations</a></p><h3
id="ComponentCheatSheet-@Inject">@Inject</h3><p>@Inject is the Swiss Army knife
of annotations; it's designed to connect your component to services, resources,
and other objects. See <a href="injection.html">Injection</a>.</p><h4
id="ComponentCheatSheet-ServiceInjection">Service Injection</h4><p>In most
cases, the injected value is a service; the service is located by type. If
there are ambiguities, caused by multiple services implementing the same
interface, you'll see injection exceptions. You can resolve those exceptions by
adding marker annotations to select a specific service, or by adding @Service
to specify the specific service ID you want.</p><rich-text-body><p>Use of
@Service is discouraged. If marker annotations are available, that is preferre
d.</p></rich-text-body><h3
id="ComponentCheatSheet-@InjectComponent">@InjectComponent</h3><p>Injects a
component from this component's template into this component's class. Injecting
a component is based on the component's ID, which should match the field name.
However, the value attribute of the @InjectComponent annotation can be
specified as well, this takes precedence over the field name.</p><p>It is
common to inject a component in order to obtain its client-side ID (used when
generating client-side JavaScript).</p><h3
id="ComponentCheatSheet-@InjectContainer">@InjectContainer</h3><p>Injects the
container of a component or, when used in a mixin, injects the component the
mixin is attached to.</p><h3
id="ComponentCheatSheet-@InjectPage">@InjectPage</h3><p>Injects a page of the
application. Normally, the page to inject is identified based on the field
type. The value attribute can be specified, in which case the page to be
injected is identified by name.</p><h3 id="ComponentCheatSh
eet-@Environmental">@Environmental</h3><p>Injects an <a
href="environmental-services.html">environmental object</a>; such objects are
request scoped but may be overridden at any time using the methods of the
Environment service. Environmental objects are used to allow outer components
to communicate with components they enclose.</p><p>Most often, @Environmental
is used with type JavaScriptSupport, which is used to add JavaScript code and
libraries to the rendered page.</p><h2
id="ComponentCheatSheet-FieldBehaviorAnnotations">Field Behavior
Annotations</h2><p>Main articles: <a href="component-classes.html">Component
Classes</a>, <a href="annotations.html">Annotations</a></p><h3
id="ComponentCheatSheet-@PageActivationContext">@PageActivationContext</h3><p>This
annotation is allowed on a <em>single</em> field; the value of the field will
be included in URLs for the page as the page's activation context. This is an
alternative to implementing event handler methods<br clear="none"> fo
r the activate and passivate events directly.</p><h3
id="ComponentCheatSheet-@Parameter">@Parameter</h3><p>Marks the field as a
component parameter. Attributes of the annotation allow the parameter to be
marked as required or optional. If the parameter value will typically be a
literal string (for example, the title parameter to a Layout component), you
should add <code>defaultPrefix=BindingConstants.LITERAL</code> to the
annotation so that users of the component won't have to use the "literal:"
binding prefix with the parameter. See <a
href="component-parameters.html">Component Parameters</a></p><h3
id="ComponentCheatSheet-@Persist">@Persist</h3><p>Marks the field as a
persistent value, one that maintains its value between requests. The default
<em>strategy</em> is to simply store the value in the session (which is created
as needed). Other strategies can be specified by name as the value attribute.
See <a href="persistent-page-data.html">Persistent Page Data</a>.</p><h3
id="Comp
onentCheatSheet-@Property">@Property</h3><p>Directs Tapestry to automatically
generate a getter and a setter for the field, converting it to a JavaBeans
property than can be referenced from the template.</p><h3
id="ComponentCheatSheet-@SessionState">@SessionState</h3><p>Marks the field as
a Session State Object (SSO). SSOs store global data, and can be injected into
any page or component. The SSOs are stored in the session, using a key based on
the Java type. SSOs are usually created on demand, but the <code>create</code>
attribute can turn this off. See <a href="session-storage.html">Session
Storage</a></p><h3
id="ComponentCheatSheet-@SessionAttribute">@SessionAttribute</h3><p>In Tapestry
5.2 and later, marks the field as a Session Attribute. Like Session State
Objects (SSO), a Session Attribute is stored in the session, however Session
Attributes are stored by using a name you choose rather than based on the Java
type. See <a href="session-storage.html">Session Storage</a>.</p><
h3
id="ComponentCheatSheet-@ActivationRequestParameter">@ActivationRequestParameter</h3><p>Fields
with this annotation will be encoded into URLs as query parameters, in much
the same way as data is encoded into the URL path. The query parameter name
matches the field name, unless the value attribute is specified.</p><h2
id="ComponentCheatSheet-MethodAnnotations">Method Annotations</h2><p>Main
articles: <a href="component-classes.html">Component Classes</a>, <a
href="annotations.html">Annotations</a></p><h3
id="ComponentCheatSheet-@OnEvent">@OnEvent</h3><p>Marks a method as an event
handler method. Such methods may have any visibility, and typically use package
private visibility (that is, no visibility keyword at all). By default, the
method will handle the action event from any component; the value attribute
controls the matched event, and the component annotation is used to limit the
event source.</p><p>An event handler method may take parameters, corresponding
the event context
associated with the event, such as the page activation context for the
activate event. The method will not be invoked if it defines more parameters
than there are values in the context.</p><p>The @RequestParameter annotation
can be used on parameters, in which case the parameters value comes from a
request query parameter, and not from the event context.</p><p>Events fired on
a component bubble up the component's container. Return a non-null value to
cancel event bubbling. What values may be returned from an event handler method
is dependent on the type of event.</p><p>You may also return true to indicate
that the event is handled and bubbling should cancel (even for events that do
not permit a return value).</p><rich-text-body><p>An alternative to @OnEvent is
the naming convention <code>on</code><em>EventName</em> or
<code>on</code><em>EventName</em><code>From</code><em>ComponentId</em>.</p></rich-text-body><h3
id="ComponentCheatSheet-@Log">@Log</h3><p>Marks the method to be logge
d for debugging purposes: method entry (with parameters) and exit (with return
value) will be logged at debug level, as will any thrown exception. This is
primarily for debugging purposes. The Logger name will match the component
classes' fully qualified class name.</p><h3
id="ComponentCheatSheet-@CommitAfter">@CommitAfter</h3><rich-text-body><p>The
support for this annotation comes from the <a
href="hibernate.html">tapestry-hibernate</a> module or tapestry-jpa
module.</p></rich-text-body><h3
id="ComponentCheatSheet-@Cached">@Cached</h3><p>Used on methods that perform
expensive operations, such as database queries. The first time such a method is
invoked, the return value is cached. Future invocations of the same method
return the cached value.</p><p>The result cache is per-request and is discarded
at the end of the request.</p><p>@Cached only works on methods that take no
parameters.</p><h2 id="ComponentCheatSheet-ParameterAnnotations">Parameter
Annotations</h2><p>Main article: <a
href="component-parameters.html">Component Parameters</a></p><h3
id="ComponentCheatSheet-@RequestParameter">@RequestParameter</h3><p>Used with
event handler methods to get the value for the parameter from a request query
parameter.</p><h2 id="ComponentCheatSheet-TypeAnnotations">Type
Annotations</h2><h3 id="ComponentCheatSheet-@Events">@Events</h3><p>Lists the
names of events that may be fired from within this component; used for
documentation purposes only.</p><h3
id="ComponentCheatSheet-@Import">@Import</h3><p>Allows JavaScript libraries and
CSS stylesheet files to be included in the rendered page. Each such file is
added to the page only once, in the order in which the page renders.</p><p>It
is allowed to use symbol expansions (with the <code>${...</code>} syntax)
inside a library or stylesheet path.</p><p>@Import may also be applied to
individual methods, in which case the import operation only occurs when the
method is invoked.</p><rich-text-body><p>When specifying a file to
import, you'll often use the prefix <code>context:</code> to indicate that the
file is stored in the web application context, and not on the classpath.
Relative paths will be on the classpath, relative to the Java
class.</p></rich-text-body><h3
id="ComponentCheatSheet-@SupportsInformalParameters">@SupportsInformalParameters</h3><p>Marks
the component as allowing informal parameters (extra attributes in the
template that do not match formally declared parameters). Normally, informal
parameters are simply discarded.</p><p>The method
ComponentResources.renderInformalParameters() can be used to include the
informal parameters within the element rendered by your component.</p><h3
id="ComponentCheatSheet-@Secure">@Secure</h3><p>Marks the page as accessible
only via secure (HTTPs). Any attempt to access the page via standard HTTP will
be redirected to the HTTPs version.</p><p>By default, the @Secure annotation is
ignored in development mode and only active in production mode.</p><h2 id="Co
mponentCheatSheet-RenderPhaseMethods">Render Phase Methods</h2><p>Main
article: <a href="component-rendering.html">Component
Rendering</a></p><p>Render phase methods are close cousins to event handler
methods; they are how Tapestry integrates your code into the overall rendering
of the page. For each render phase, there's an annotation and corresponding
naming convention to define a render phase method:</p><div
class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1"
rowspan="1" class="confluenceTh"><p>Annotation</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>Method Name</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>General Use</p></th></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p>@SetupRender</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>setupRender()</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Initializes the component
before rendering</p></td></tr><tr><td colspan="1" rowspan="1" class="co
nfluenceTd"><p>@BeginRender</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>beginRender()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Renders the element and primary attributes of the
component</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>@AfterRender</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>afterRender()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Closes the element started in
beginRender()</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>@CleanupRender</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>cleanupRender()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Performs cleanup after all rendering of the component
finishes</p></td></tr></tbody></table></div><p>Render phase methods either take
no parameters, or take a single parameter of type MarkupWriter.</p><p>Render
phase methods may return <code>void</code>, a <code>boolean</code>, or a
<em>rendera
ble object</em>.</p><rich-text-body><p>Generally, a <code>renderable
object</code> is a <a class="external-link"
href="http://tapestry.apache.org/5.4/apidocs/org/apache/tapestry5/Block.html";>Block</a>
or a component. The object is pushed onto the stack of rendering operations,
temporarily replacing the current component as the object to be
rendered.</p></rich-text-body><p>Returning true is the same as returning void;
it means that the component should follow the typical
flow:</p><ul><li>@SetupRender</li><li>@BeginRender</li><li>Render the
component's template, if any</li><li>Render the component's
body</li><li>@AfterRender</li><li>@CleanupRender</li></ul><p>If a component has
a template, the component's body will only render if the template contains a
<t:body> element. If a component has no template, then it will always
render its body (between @BeginRender and @AfterRender).</p><p>A render phase
method may also return false, in which case the flow continues to an alternate r
ender phase, as per the chart in the <a
href="component-rendering.html">Component Rendering</a> reference
page.</p><p>The most common cases:</p><ul><li>return <code>false</code> from
@BeginRender to skip the rendering of the component's template and/or body, and
continue with @AfterRender</li><li>return <code>false</code> from @AfterRender
to return to @BeginRender (this is used in component, such as
<code>Loop</code>, that render themselves multiple times)</li></ul><h2
id="ComponentCheatSheet-PageLifeCycleMethods">Page Life Cycle
Methods</h2><p>Main article: <a href="page-life-cycle.html">Page Life
Cycle</a></p><p>Pages have a life cycle and this is represented by a
<em>third</em> set of annotations or method naming conventions. Life cycle
methods may appear on a page or any component of a page.</p><div
class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1"
rowspan="1" class="confluenceTh"><p>Annotation</p></th><th colspan="1"
rowspan="1" class="confluenceTh
"><p>Method Name</p></th><th colspan="1" rowspan="1"
class="confluenceTh"><p>Description</p></th></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p>@PageLoaded</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>pageLoaded()</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>The page instance has been loaded but not
yet attached for the first time.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>@PageAttached</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>pageAttached()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>The page is being used within a particular request.
This occurs before the activate event.</p></td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p>@PageReset</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>pageReset()</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>See notes below.</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p>@PageDetache
d</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>pageDetached()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>End of request
notification.</p></td></tr></tbody></table></div><p>Page life cycle methods may
be any visibility. They must take no parameters and return void.</p><p>Page
life cycle methods are of lower importance starting in Tapestry 5.2, since page
instances are now shared across threads, rather than pooled.</p><p>The
@PageReset life cycle is new in Tapestry 5.2. It will be invoked on a page
render request when linked to from some other page of the application. This is
to allow the page to reset its state, if any, when a user returns to the page
from some other part of the application.</p><h2
id="ComponentCheatSheet-ConfiguringAnnotations">Configuring
Annotations</h2><p>The SymbolProvider service has two interfaces :
FactoryDefaults and ApplicationDefaults. Tapestry provides 2 annotations in
order to define which implementation you want to overri
de in your AppModule : </p><ul><li><p>@FactoryDefaults</p><parameter
ac:name="title">AppModule with
@FactoryDefaults</parameter><plain-text-body>@Contribute(SymbolProvider.class)
+ <div id="ConfluenceContent"><p> </p><p>This is a summary
of the more common annotations and methods you can add to Tapestry pages and
component classes.</p><div class="aui-label" style="float:right" title="Related
Articles"><h3>Related Articles</h3><ul class="content-by-label"><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default"
title="Page">Page:</span>
+ </div>
+ <div class="details">
+ <a href="component-parameters.html">Component Parameters</a>
+ </div> </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default"
title="Page">Page:</span>
+ </div>
+ <div class="details">
+ <a href="templating-and-markup-faq.html">Templating and Markup FAQ</a>
+ </div> </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default"
title="Page">Page:</span>
+ </div>
+ <div class="details">
+ <a href="component-classes.html">Component Classes</a>
+ </div> </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default"
title="Page">Page:</span>
+ </div>
+ <div class="details">
+ <a href="component-reference.html">Component Reference</a>
+ </div> </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default"
title="Page">Page:</span>
+ </div>
+ <div class="details">
+ <a href="component-libraries.html">Component Libraries</a>
+ </div> </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default"
title="Page">Page:</span>
+ </div>
+ <div class="details">
+ <a href="page-and-component-classes-faq.html">Page And Component Classes
FAQ</a>
+ </div> </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default"
title="Page">Page:</span>
+ </div>
+ <div class="details">
+ <a href="component-templates.html">Component Templates</a>
+ </div> </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default"
title="Page">Page:</span>
+ </div>
+ <div class="details">
+ <a href="component-cheat-sheet.html">Component Cheat Sheet</a>
+ </div> </li></ul></div><p>For an exhaustive list, see the <a
href="annotations.html">annotations list</a>.</p><h2
id="ComponentCheatSheet-FieldInjectionAnnotations">Field Injection
Annotations</h2><p>Main articles: <a href="component-classes.html">Component
Classes</a>, <a href="injection.html">Injection</a>, <a
href="annotations.html">Annotations</a></p><h3
id="ComponentCheatSheet-@Inject">@Inject</h3><p>@Inject is the Swiss Army knife
of annotations; it's designed to connect your component to services, resources,
and other objects. See <a href="injection.html">Injection</a>.</p><h4
id="ComponentCheatSheet-ServiceInjection">Service Injection</h4><p>In most
cases, the injected value is a service; the service is located by type. If
there are ambiguities, caused by multiple services implementing the same
interface, you'll see injection exceptions. You can resolve those exceptions by
adding marker annotations to select a specific service, or by adding @Service
to specify the spe
cific service ID you want.</p><div class="confluence-information-macro
confluence-information-macro-note"><span class="aui-icon aui-icon-small
aui-iconfont-warning confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>Use of @Service is discouraged. If
marker annotations are available, that is preferred.</p></div></div><h3
id="ComponentCheatSheet-@InjectComponent">@InjectComponent</h3><p>Injects a
component from this component's template into this component's class. Injecting
a component is based on the component's ID, which should match the field name.
However, the value attribute of the @InjectComponent annotation can be
specified as well, this takes precedence over the field name.</p><p>It is
common to inject a component in order to obtain its client-side ID (used when
generating client-side JavaScript).</p><h3
id="ComponentCheatSheet-@InjectContainer">@InjectContainer</h3><p>Injects the
container of a component or, when used in a mixin, inje
cts the component the mixin is attached to.</p><h3
id="ComponentCheatSheet-@InjectPage">@InjectPage</h3><p>Injects a page of the
application. Normally, the page to inject is identified based on the field
type. The value attribute can be specified, in which case the page to be
injected is identified by name.</p><h3
id="ComponentCheatSheet-@Environmental">@Environmental</h3><p>Injects an <a
href="environmental-services.html">environmental object</a>; such objects are
request scoped but may be overridden at any time using the methods of the
Environment service. Environmental objects are used to allow outer components
to communicate with components they enclose.</p><p>Most often, @Environmental
is used with type JavaScriptSupport, which is used to add JavaScript code and
libraries to the rendered page.</p><h2
id="ComponentCheatSheet-FieldBehaviorAnnotations">Field Behavior
Annotations</h2><p>Main articles: <a href="component-classes.html">Component
Classes</a>, <a href="annotations.h
tml">Annotations</a></p><h3
id="ComponentCheatSheet-@PageActivationContext">@PageActivationContext</h3><p>This
annotation is allowed on a <em>single</em> field; the value of the field will
be included in URLs for the page as the page's activation context. This is an
alternative to implementing event handler methods<br clear="none"> for the
activate and passivate events directly.</p><h3
id="ComponentCheatSheet-@Parameter">@Parameter</h3><p>Marks the field as a
component parameter. Attributes of the annotation allow the parameter to be
marked as required or optional. If the parameter value will typically be a
literal string (for example, the title parameter to a Layout component), you
should add <code>defaultPrefix=BindingConstants.LITERAL</code> to the
annotation so that users of the component won't have to use the "literal:"
binding prefix with the parameter. See <a
href="component-parameters.html">Component Parameters</a></p><h3
id="ComponentCheatSheet-@Persist">@Persist</h3><p>Ma
rks the field as a persistent value, one that maintains its value between
requests. The default <em>strategy</em> is to simply store the value in the
session (which is created as needed). Other strategies can be specified by name
as the value attribute. See <a href="persistent-page-data.html">Persistent
Page Data</a>.</p><h3
id="ComponentCheatSheet-@Property">@Property</h3><p>Directs Tapestry to
automatically generate a getter and a setter for the field, converting it to a
JavaBeans property than can be referenced from the template.</p><h3
id="ComponentCheatSheet-@SessionState">@SessionState</h3><p>Marks the field as
a Session State Object (SSO). SSOs store global data, and can be injected into
any page or component. The SSOs are stored in the session, using a key based on
the Java type. SSOs are usually created on demand, but the <code>create</code>
attribute can turn this off. See <a href="session-storage.html">Session
Storage</a></p><h3 id="ComponentCheatSheet-@SessionAttribute
">@SessionAttribute</h3><p>In Tapestry 5.2 and later, marks the field as a
Session Attribute. Like Session State Objects (SSO), a Session Attribute is
stored in the session, however Session Attributes are stored by using a name
you choose rather than based on the Java type. See <a
href="session-storage.html">Session Storage</a>.</p><h3
id="ComponentCheatSheet-@ActivationRequestParameter">@ActivationRequestParameter</h3><p>Fields
with this annotation will be encoded into URLs as query parameters, in much
the same way as data is encoded into the URL path. The query parameter name
matches the field name, unless the value attribute is specified.</p><h2
id="ComponentCheatSheet-MethodAnnotations">Method Annotations</h2><p>Main
articles: <a href="component-classes.html">Component Classes</a>, <a
href="annotations.html">Annotations</a></p><h3
id="ComponentCheatSheet-@OnEvent">@OnEvent</h3><p>Marks a method as an event
handler method. Such methods may have any visibility, and typically us
e package private visibility (that is, no visibility keyword at all). By
default, the method will handle the action event from any component; the value
attribute controls the matched event, and the component annotation is used to
limit the event source.</p><p>An event handler method may take parameters,
corresponding the event context associated with the event, such as the page
activation context for the activate event. The method will not be invoked if it
defines more parameters than there are values in the context.</p><p>The
@RequestParameter annotation can be used on parameters, in which case the
parameters value comes from a request query parameter, and not from the event
context.</p><p>Events fired on a component bubble up the component's container.
Return a non-null value to cancel event bubbling. What values may be returned
from an event handler method is dependent on the type of event.</p><p>You may
also return true to indicate that the event is handled and bubbling should c
ancel (even for events that do not permit a return value).</p><div
class="confluence-information-macro confluence-information-macro-note"><span
class="aui-icon aui-icon-small aui-iconfont-warning
confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>An alternative to @OnEvent is the
naming convention <code>on</code><em>EventName</em> or
<code>on</code><em>EventName</em><code>From</code><em>ComponentId</em>.</p></div></div><h3
id="ComponentCheatSheet-@Log">@Log</h3><p>Marks the method to be logged for
debugging purposes: method entry (with parameters) and exit (with return value)
will be logged at debug level, as will any thrown exception. This is primarily
for debugging purposes. The Logger name will match the component classes' fully
qualified class name.</p><h3
id="ComponentCheatSheet-@CommitAfter">@CommitAfter</h3><div
class="confluence-information-macro confluence-information-macro-note"><span
class="aui-icon aui-icon-small aui-iconfont-warn
ing confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>The support for this annotation
comes from the <a href="hibernate.html">tapestry-hibernate</a> module or
tapestry-jpa module.</p></div></div><h3
id="ComponentCheatSheet-@Cached">@Cached</h3><p>Used on methods that perform
expensive operations, such as database queries. The first time such a method is
invoked, the return value is cached. Future invocations of the same method
return the cached value.</p><p>The result cache is per-request and is discarded
at the end of the request.</p><p>@Cached only works on methods that take no
parameters.</p><h2 id="ComponentCheatSheet-ParameterAnnotations">Parameter
Annotations</h2><p>Main article: <a href="component-parameters.html">Component
Parameters</a></p><h3
id="ComponentCheatSheet-@RequestParameter">@RequestParameter</h3><p>Used with
event handler methods to get the value for the parameter from a request query
parameter.</p><h2 id="ComponentChe
atSheet-TypeAnnotations">Type Annotations</h2><h3
id="ComponentCheatSheet-@Events">@Events</h3><p>Lists the names of events that
may be fired from within this component; used for documentation purposes
only.</p><h3 id="ComponentCheatSheet-@Import">@Import</h3><p>Allows JavaScript
libraries and CSS stylesheet files to be included in the rendered page. Each
such file is added to the page only once, in the order in which the page
renders.</p><p>It is allowed to use symbol expansions (with the
<code>${...</code>} syntax) inside a library or stylesheet path.</p><p>@Import
may also be applied to individual methods, in which case the import operation
only occurs when the method is invoked.</p><div
class="confluence-information-macro confluence-information-macro-note"><span
class="aui-icon aui-icon-small aui-iconfont-warning
confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>When specifying a file to import,
you'll often use the prefix <code>context:
</code> to indicate that the file is stored in the web application context,
and not on the classpath. Relative paths will be on the classpath, relative to
the Java class.</p></div></div><h3
id="ComponentCheatSheet-@SupportsInformalParameters">@SupportsInformalParameters</h3><p>Marks
the component as allowing informal parameters (extra attributes in the
template that do not match formally declared parameters). Normally, informal
parameters are simply discarded.</p><p>The method
ComponentResources.renderInformalParameters() can be used to include the
informal parameters within the element rendered by your component.</p><h3
id="ComponentCheatSheet-@Secure">@Secure</h3><p>Marks the page as accessible
only via secure (HTTPs). Any attempt to access the page via standard HTTP will
be redirected to the HTTPs version.</p><p>By default, the @Secure annotation is
ignored in development mode and only active in production mode.</p><h2
id="ComponentCheatSheet-RenderPhaseMethods">Render Phase Meth
ods</h2><p>Main article: <a href="component-rendering.html">Component
Rendering</a></p><p>Render phase methods are close cousins to event handler
methods; they are how Tapestry integrates your code into the overall rendering
of the page. For each render phase, there's an annotation and corresponding
naming convention to define a render phase method:</p><div
class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1"
rowspan="1" class="confluenceTh"><p>Annotation</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>Method Name</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>General Use</p></th></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p>@SetupRender</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>setupRender()</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Initializes the component
before rendering</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>@BeginRender</p></td><td colspan="1" row
span="1" class="confluenceTd"><p>beginRender()</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Renders the element and primary attributes
of the component</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>@AfterRender</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>afterRender()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Closes the element started in
beginRender()</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>@CleanupRender</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>cleanupRender()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Performs cleanup after all rendering of the component
finishes</p></td></tr></tbody></table></div><p>Render phase methods either take
no parameters, or take a single parameter of type MarkupWriter.</p><p>Render
phase methods may return <code>void</code>, a <code>boolean</code>, or a
<em>renderable object</em>.</p><div class="confluence-information-
macro confluence-information-macro-note"><span class="aui-icon aui-icon-small
aui-iconfont-warning confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>Generally, a <code>renderable
object</code> is a <a class="external-link"
href="http://tapestry.apache.org/5.4/apidocs/org/apache/tapestry5/Block.html";>Block</a>
or a component. The object is pushed onto the stack of rendering operations,
temporarily replacing the current component as the object to be
rendered.</p></div></div><p>Returning true is the same as returning void; it
means that the component should follow the typical
flow:</p><ul><li>@SetupRender</li><li>@BeginRender</li><li>Render the
component's template, if any</li><li>Render the component's
body</li><li>@AfterRender</li><li>@CleanupRender</li></ul><p>If a component has
a template, the component's body will only render if the template contains a
<t:body> element. If a component has no template, then it will always
render its
body (between @BeginRender and @AfterRender).</p><p>A render phase method may
also return false, in which case the flow continues to an alternate render
phase, as per the chart in the <a href="component-rendering.html">Component
Rendering</a> reference page.</p><p>The most common cases:</p><ul><li>return
<code>false</code> from @BeginRender to skip the rendering of the component's
template and/or body, and continue with @AfterRender</li><li>return
<code>false</code> from @AfterRender to return to @BeginRender (this is used in
component, such as <code>Loop</code>, that render themselves multiple
times)</li></ul><h2 id="ComponentCheatSheet-PageLifeCycleMethods">Page Life
Cycle Methods</h2><p>Main article: <a href="page-life-cycle.html">Page Life
Cycle</a></p><p>Pages have a life cycle and this is represented by a
<em>third</em> set of annotations or method naming conventions. Life cycle
methods may appear on a page or any component of a page.</p><div
class="table-wrap"><table class=
"confluenceTable"><tbody><tr><th colspan="1" rowspan="1"
class="confluenceTh"><p>Annotation</p></th><th colspan="1" rowspan="1"
class="confluenceTh"><p>Method Name</p></th><th colspan="1" rowspan="1"
class="confluenceTh"><p>Description</p></th></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p>@PageLoaded</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>pageLoaded()</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>The page instance has been loaded but not
yet attached for the first time.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>@PageAttached</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>pageAttached()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>The page is being used within a particular request.
This occurs before the activate event.</p></td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p>@PageReset</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>pageReset()</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>See notes
below.</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>@PageDetached</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>pageDetached()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>End of request
notification.</p></td></tr></tbody></table></div><p>Page life cycle methods may
be any visibility. They must take no parameters and return void.</p><p>Page
life cycle methods are of lower importance starting in Tapestry 5.2, since page
instances are now shared across threads, rather than pooled.</p><p>The
@PageReset life cycle is new in Tapestry 5.2. It will be invoked on a page
render request when linked to from some other page of the application. This is
to allow the page to reset its state, if any, when a user returns to the page
from some other part of the application.</p><h2
id="ComponentCheatSheet-ConfiguringAnnotations">Configuring
Annotations</h2><p>The SymbolProvider service has t
wo interfaces : FactoryDefaults and ApplicationDefaults. Tapestry provides 2
annotations in order to define which implementation you want to override in
your AppModule : </p><ul><li><p>@FactoryDefaults</p><div class="code panel
pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl"
style="border-bottom-width: 1px;"><b>AppModule with
@FactoryDefaults</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">@Contribute(SymbolProvider.class)
@FactoryDefaults
public void setParam(MappedConfiguration< String, String> configuration){
configuration.add(SymbolConstants.PRODUCTION_MODE, "false");
-}</plain-text-body></li><li><p>@ApplicationDefaults</p><parameter
ac:name="title">AppModule with
@ApplicationDefaults</parameter><plain-text-body>@Contribute(SymbolProvider.class)
+}</pre>
+</div></div></li><li><p>@ApplicationDefaults</p><div class="code panel pdl"
style="border-width: 1px;"><div class="codeHeader panelHeader pdl"
style="border-bottom-width: 1px;"><b>AppModule with
@ApplicationDefaults</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">@Contribute(SymbolProvider.class)
@ApplicationDefaults
public void setParam(MappedConfiguration< String, String> configuration){
configuration.add(SymbolConstants.PRODUCTION_MODE, "false");
-}</plain-text-body></li></ul><p> </p><p></p></div>
+}</pre>
+</div></div></li></ul><p> </p><p></p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/component-classes.html
==============================================================================
--- websites/production/tapestry/content/component-classes.html (original)
+++ websites/production/tapestry/content/component-classes.html Wed Sep 20
12:29:16 2017
@@ -27,6 +27,15 @@
</title>
<link type="text/css" rel="stylesheet" href="/resources/space.css" />
+ <link href='/resources/highlighter/styles/shCoreCXF.css'
rel='stylesheet' type='text/css' />
+ <link href='/resources/highlighter/styles/shThemeCXF.css' rel='stylesheet'
type='text/css' />
+ <script src='/resources/highlighter/scripts/shCore.js'
type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushJava.js'
type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushXml.js'
type='text/javascript'></script>
+ <script>
+ SyntaxHighlighter.defaults['toolbar'] = false;
+ SyntaxHighlighter.all();
+ </script>
<link href="/styles/style.css" rel="stylesheet" type="text/css"/>
@@ -67,14 +76,88 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><p>A <strong>component
class</strong> is the class associated with a page, component or mixin in
your Tapestry web application. Classes for pages, components and mixins are all
created in an identical way. They are pure POJOs (Plain Old Java Objects),
typically with annotations and conventionally named methods. They are not
<em>abstract</em>, nor do they need to extend base classes or implement
interfaces.</p><parameter ac:name="style">float:right</parameter><parameter
ac:name="title">Related Articles</parameter><parameter
ac:name="class">aui-label</parameter><rich-text-body><parameter
ac:name="showLabels">false</parameter><parameter
ac:name="showSpace">false</parameter><parameter ac:name="title">Related
Articles</parameter><parameter ac:name="cql">label in
("component-classes","components") and space =
currentSpace()</parameter></rich-text-body><p>In most cases, each component
class will have a corresponding <a href="component-templ
ates.html">component template</a>. However, it is also possible for a
component class to emit all of its markup itself, without using a
template.</p><p><em>For Tapestry 4 Users: Component classes in Tapestry 5 are
much easier than in Tapestry 4. There are no base classes to extend from, the
classes are concrete (not abstract), and there's no XML file. There is still a
bit of configuration in the form of Java annotations, but those now go directly
onto fields of your class, rather than on abstract getters and
setters.</em></p><h2 id="ComponentClasses-CreatingaTrivialComponent">Creating a
Trivial Component</h2><p>Creating a page or component in Tapestry 5 is a
breeze. There are only a few constraints:</p><ul><li>There must be a public
Java class.</li><li>The class must be in the correct package (see
below).</li><li>The class must have a public, no-arguments constructor. (The
default one provided by the compiler is fine.)</li></ul><p>Here's a minimal
component that outputs a fixed mess
age, using a <a href="component-templates.html">template</a> with a matching
file name:</p><rich-text-body><rich-text-body><parameter
ac:name="language">java</parameter><parameter
ac:name="title">HelloWorld.java</parameter><plain-text-body>package
org.example.myapp.components;
+ <div id="ConfluenceContent"><p>A <strong>component
class</strong> is the class associated with a page, component or mixin in
your Tapestry web application. Classes for pages, components and mixins are all
created in an identical way. They are pure POJOs (Plain Old Java Objects),
typically with annotations and conventionally named methods. They are not
<em>abstract</em>, nor do they need to extend base classes or implement
interfaces.</p><div class="aui-label" style="float:right" title="Related
Articles">
+
+
+
+
+
+
+
+
+<h3>Related Articles</h3>
+
+<ul class="content-by-label"><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small
aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="component-reference.html">Component
Reference</a>
+
+
+ </div>
+ </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small
aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="component-libraries.html">Component
Libraries</a>
+
+
+ </div>
+ </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small
aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="page-and-component-classes-faq.html">Page
And Component Classes FAQ</a>
+
+
+ </div>
+ </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small
aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="component-templates.html">Component
Templates</a>
+
+
+ </div>
+ </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small
aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="component-cheat-sheet.html">Component Cheat
Sheet</a>
+
+
+ </div>
+ </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small
aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="component-parameters.html">Component
Parameters</a>
+
+
+ </div>
+ </li></ul>
+</div>
+
+
+<p>In most cases, each component class will have a corresponding <a
href="component-templates.html">component template</a>. However, it is also
possible for a component class to emit all of its markup itself, without using
a template.</p><p><em>For Tapestry 4 Users: Component classes in Tapestry 5 are
much easier than in Tapestry 4. There are no base classes to extend from, the
classes are concrete (not abstract), and there's no XML file. There is still a
bit of configuration in the form of Java annotations, but those now go directly
onto fields of your class, rather than on abstract getters and
setters.</em></p><h2 id="ComponentClasses-CreatingaTrivialComponent">Creating a
Trivial Component</h2><p>Creating a page or component in Tapestry 5 is a
breeze. There are only a few constraints:</p><ul><li>There must be a public
Java class.</li><li>The class must be in the correct package (see
below).</li><li>The class must have a public, no-arguments constructor. (The
default one provided
by the compiler is fine.)</li></ul><p>Here's a minimal component that outputs
a fixed message, using a <a href="component-templates.html">template</a> with
a matching file name:</p><div class="sectionColumnWrapper"><div
class="sectionMacro"><div class="sectionMacroRow"><div class="columnMacro"><div
class="code panel pdl" style="border-width: 1px;"><div class="codeHeader
panelHeader pdl" style="border-bottom-width:
1px;"><b>HelloWorld.java</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">package org.example.myapp.components;
public class HelloWorld
{
}
-</plain-text-body></rich-text-body><rich-text-body><parameter
ac:name="language">xml</parameter><parameter
ac:name="title">HelloWorld.tml</parameter><plain-text-body><html>
+</pre>
+</div></div></div><div class="columnMacro"><div class="code panel pdl"
style="border-width: 1px;"><div class="codeHeader panelHeader pdl"
style="border-bottom-width: 1px;"><b>HelloWorld.tml</b></div><div
class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><html>
Bonjour from HelloWorld component.
</html>
-</plain-text-body></rich-text-body></rich-text-body><p>In the example above,
the HelloWorld class contains no code at all (except what it inherits from the
Object class and what Tapestry adds invisibly).</p><p>And here's a component
that does the same thing, but without needing a template:</p><parameter
ac:name="language">java</parameter><parameter ac:name="title">HelloWorld.java
-- without a template</parameter><plain-text-body>package
org.example.myapp.components;
+</pre>
+</div></div></div></div></div></div><p>In the example above, the HelloWorld
class contains no code at all (except what it inherits from the Object class
and what Tapestry adds invisibly).</p><p>And here's a component that does the
same thing, but without needing a template:</p><div class="code panel pdl"
style="border-width: 1px;"><div class="codeHeader panelHeader pdl"
style="border-bottom-width: 1px;"><b>HelloWorld.java – without a
template</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">package org.example.myapp.components;
import org.apache.tapestry5.MarkupWriter;
import org.apache.tapestry5.annotations.BeginRender;
@@ -87,13 +170,15 @@ public class HelloWorld
writer.write("Bonjour from HelloWorld component.");
}
}
-</plain-text-body><p>In this example, just like the first one, the component's
only job is to write out a fixed message. The @<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/BeginRender.html";>BeginRender</a>
annotation is a type of <em><a href="component-rendering.html">render phase
annotation</a></em>, a method annotation that instructs Tapestry when and under
what circumstances to invoke methods of your class.</p><p>These methods are not
necessarily public; they can have any access level you like (unlike in Tapestry
4). By convention they usually have package-private access level (the
default).</p><h2 id="ComponentClasses-ComponentPackages">Component
Packages</h2><p>Component classes must exist within an appropriate package
(this is necessary for runtime code transformation and class reloading to
operate).</p><p>These packages exist under the application's root package, as
follows:</p><ul><li>For pages, place classes in
<em>root</em>.<strong>pages</strong>. Page names are mapped to classes within
this package.</li><li>For mixins, place classes in
<em>root</em>.<strong>mixins</strong>. Mixin types are mapped to classes within
this package.</li><li>For other components, place classes in
<em>root</em>.<strong>components</strong>. Component types are mapped to
classes within this package.</li></ul><p>In addition, it is common for an
application to have base classes, often <em>abstract</em> base classes, that
should not be directly referenced. These should <em>not</em> go in the
<strong>pages</strong>, <strong>components</strong> or <strong>mixins</strong>
packages, because they then look like valid pages, components or mixins.
Instead, use the <em>root</em>.<strong>base</strong> package to store such base
classes.</p><rich-text-body><p>Only component classes should go in any of these
controlled packages; classes representing data, or interfaces, or anything that
isn't precisely a component class, must
go elsewhere. Any top-level class in any of the controlled packages will be
transformed at runtime. The only exception is inner classes (anonymous or not),
which are loaded by the same class loader as the component class loader, but
not transformed as components.</p></rich-text-body><h2
id="ComponentClasses-Sub-Folders/Sub-Packages">Sub-Folders /
Sub-Packages</h2><p>Classes do not have to go directly inside the package
(pages, components, mixins, etc.). It is valid to create a sub-package to store
some of the classes. The sub-package name becomes part of the page name or
component type. Thus you might define a page component
<code>com.example.myapp.pages.admin.CreateUser</code> and the logical page name
(which often shows up inside URLs) will be
<strong>admin/CreateUser</strong>.</p><p>Tapestry performs some simple
optimizations of the logical page name (or component type, or mixin type). It
checks to see if the package name is either a prefix or a suffix of the
unqualified class na
me (case insensitively, of course) and removes the prefix or suffix if so. The
net result is that a class name such as
<code>com.example.myapp.pages.user.EditUser</code> will have a page name of
<code>user/Edit</code> (instead of user<code>/EditUser</code>). The goal here
is to provide shorter, more natural URLs.</p><h2
id="ComponentClasses-IndexPages">Index Pages</h2><p>One special simplification
exists for Index pages: if the logical page name is Index after removing the
package name from the unqualified class name, it will map to the root of that
folder. A class such as <code>com.example.myapp.pages.user.IndexUser</code> or
<code>com.example.myapp.pages.user.UserIndex</code> will have a page name of
<code>user/</code>.</p><p>In previous versions of Tapestry there was also the
concept of a start page configured with the <code><a
href="configuration.html">tapestry.start-page-name</a></code> configuration
symbol (defaults to "start"). If a page with a name as configured with that s
ymbol exists at the root level, this page is used as the root URL. This has
precedence over an existing Index page. If for example you have a page class
<code>com.example.myapp.pages.Start</code> it will map to
<code>/</code>.</p><rich-text-body><p>Use of start-pages is discouraged and
support for it will eventually be removed. Use an Index page
instead.</p></rich-text-body><h2 id="ComponentClasses-Pagesvs.Components">Pages
vs. Components</h2><p>The distinction between pages and component is very, very
small. The primary difference is the package name:
<em>root</em>.<strong>pages</strong>.<em>PageName</em> for pages, and
<em>root</em>.<strong>components</strong>.<em>ComponentType</em> for
components. Conceptually, page components are simply the <em>root
component</em> of a page's component tree.</p><p><em>For Tapestry 4 users:
there was a much greater distinction in Tapestry 4 between pages and
components, which showed up as separate interfaces and a hierarchy of abstract
implementa
tions to extend your classes from.</em></p><h2
id="ComponentClasses-ClassTransformation">Class Transformation</h2><p>Tapestry
uses your class as a starting point. It <em>transforms</em> your class at
runtime. This is necessary for a number of reasons, including to address how
Tapestry shares pages between requests.</p><p>For the most part, these
transformations are both sensible and invisible. In a few limited cases, they
comprise a marginally <a class="external-link"
href="http://www.joelonsoftware.com/printerFriendly/articles/LeakyAbstractions.html";
rel="nofollow">leaky abstraction</a> – for instance, the scope
restrictions on instance variables described below – but the programming
model in general supports a very high level of developer
productivity.</p><p>Because transformation doesn't occur until
<em>runtime</em>, the build stage of your application is not affected by the
fact that you are creating a Tapestry application. Further, your classes are
absolu
tely simple POJOs during unit testing.</p><h2
id="ComponentClasses-LiveClassReloading">Live Class Reloading</h2><p>Main
Article: <a href="class-reloading.html">Class Reloading</a></p><p>Component
classes are monitored for changes by the framework. <a
href="class-reloading.html">Classes are reloaded when changed</a>. This allows
you to build your application with a speed approaching that of a scripting
environment, without sacrificing any of the power of the Java
platform.</p><p>And it's fast! You won't even notice that this magic class
reloading has occurred.</p><p>The net result: super productivity — change
your class, see the change instantly. This is designed to be a blend of the
best of scripting environments (such as Python or Ruby) with all the speed and
power of Java backing it up.</p><p>However, class reloading <em>only</em>
applies to component classes (pages, components and mixins) and, starting in
5.2, Tapestry IOC-based service implementations (with some restrict
ions). Other classes, such as service interfaces, entity/model classes, and
other data objects, are loaded by the normal class loader and not subject to
live class reloading.</p><h2 id="ComponentClasses-InstanceVariables">Instance
Variables</h2><p>Tapestry components may have instance variables (unlike
Tapestry 4, where you had to use <em>abstract properties</em>).</p><p>Since
release 5.3.2, instance variables may be protected, or package private (that
is, no access modifier). Under specific circumstances they may even be public
(public fields must either be final, or have the @<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Retain.html";>Retain</a> annotation).</p><p><span
style="line-height: 1.4285715;">Be aware that you will need to either provide
getter and setter methods to access your classes' instance variables, or else
annotate the fields with</span><span style="line-height:
1.4285715;"> @</span><a class="
external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Property.html";
style="line-height: 1.4285715;">Property</a>.</p><h2
id="ComponentClasses-TransientInstanceVariables">Transient Instance
Variables</h2><p>Unless an instance variable is decorated with an annotation,
it will be a <em>transient</em> instance variable. This means that its value
resets to its default value at the end of reach request (when the <a
href="page-life-cycle.html">page is detached from the
request</a>).</p><parameter ac:name="title">About
initialization</parameter><rich-text-body><p>Never initialize an instance field
to a <em>mutable</em> object at the point of declaration. If this is done, the
instance created from that initializer becomes the default value for that field
and is reused inside the component on every request. This could cause state to
inadvertently be shared between different sessions in an
application.</p></rich-text-body>
+</pre>
+</div></div><p>In this example, just like the first one, the component's only
job is to write out a fixed message. The @<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/BeginRender.html";>BeginRender</a>
annotation is a type of <em><a href="component-rendering.html">render phase
annotation</a></em>, a method annotation that instructs Tapestry when and under
what circumstances to invoke methods of your class.</p><p>These methods are not
necessarily public; they can have any access level you like (unlike in Tapestry
4). By convention they usually have package-private access level (the
default).</p><h2 id="ComponentClasses-ComponentPackages">Component
Packages</h2><p>Component classes must exist within an appropriate package
(this is necessary for runtime code transformation and class reloading to
operate).</p><p>These packages exist under the application's root package, as
follows:</p><ul><li>For pages, place classes in <em>ro
ot</em>.<strong>pages</strong>. Page names are mapped to classes within this
package.</li><li>For mixins, place classes in
<em>root</em>.<strong>mixins</strong>. Mixin types are mapped to classes within
this package.</li><li>For other components, place classes in
<em>root</em>.<strong>components</strong>. Component types are mapped to
classes within this package.</li></ul><p>In addition, it is common for an
application to have base classes, often <em>abstract</em> base classes, that
should not be directly referenced. These should <em>not</em> go in the
<strong>pages</strong>, <strong>components</strong> or <strong>mixins</strong>
packages, because they then look like valid pages, components or mixins.
Instead, use the <em>root</em>.<strong>base</strong> package to store such base
classes.</p><div class="confluence-information-macro
confluence-information-macro-warning"><span class="aui-icon aui-icon-small
aui-iconfont-error confluence-information-macro-icon"></span><div class="confl
uence-information-macro-body"><p>Only component classes should go in any of
these controlled packages; classes representing data, or interfaces, or
anything that isn't precisely a component class, must go elsewhere. Any
top-level class in any of the controlled packages will be transformed at
runtime. The only exception is inner classes (anonymous or not), which are
loaded by the same class loader as the component class loader, but not
transformed as components.</p></div></div><h2
id="ComponentClasses-Sub-Folders/Sub-Packages">Sub-Folders /
Sub-Packages</h2><p>Classes do not have to go directly inside the package
(pages, components, mixins, etc.). It is valid to create a sub-package to store
some of the classes. The sub-package name becomes part of the page name or
component type. Thus you might define a page component
<code>com.example.myapp.pages.admin.CreateUser</code> and the logical page name
(which often shows up inside URLs) will be
<strong>admin/CreateUser</strong>.</p><p>Tap
estry performs some simple optimizations of the logical page name (or
component type, or mixin type). It checks to see if the package name is either
a prefix or a suffix of the unqualified class name (case insensitively, of
course) and removes the prefix or suffix if so. The net result is that a class
name such as <code>com.example.myapp.pages.user.EditUser</code> will have a
page name of <code>user/Edit</code> (instead of user<code>/EditUser</code>).
The goal here is to provide shorter, more natural URLs.</p><h2
id="ComponentClasses-IndexPages">Index Pages</h2><p>One special simplification
exists for Index pages: if the logical page name is Index after removing the
package name from the unqualified class name, it will map to the root of that
folder. A class such as <code>com.example.myapp.pages.user.IndexUser</code> or
<code>com.example.myapp.pages.user.UserIndex</code> will have a page name of
<code>user/</code>.</p><p>In previous versions of Tapestry there was also the
concept of
a start page configured with the <code><a
href="configuration.html">tapestry.start-page-name</a></code> configuration
symbol (defaults to "start"). If a page with a name as configured with that
symbol exists at the root level, this page is used as the root URL. This has
precedence over an existing Index page. If for example you have a page class
<code>com.example.myapp.pages.Start</code> it will map to
<code>/</code>.</p><div class="confluence-information-macro
confluence-information-macro-warning"><span class="aui-icon aui-icon-small
aui-iconfont-error confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>Use of start-pages is discouraged
and support for it will eventually be removed. Use an Index page
instead.</p></div></div><h2 id="ComponentClasses-Pagesvs.Components">Pages vs.
Components</h2><p>The distinction between pages and component is very, very
small. The primary difference is the package name:
<em>root</em>.<strong>pages</strong>.<
em>PageName</em> for pages, and
<em>root</em>.<strong>components</strong>.<em>ComponentType</em> for
components. Conceptually, page components are simply the <em>root
component</em> of a page's component tree.</p><p><em>For Tapestry 4 users:
there was a much greater distinction in Tapestry 4 between pages and
components, which showed up as separate interfaces and a hierarchy of abstract
implementations to extend your classes from.</em></p><h2
id="ComponentClasses-ClassTransformation">Class Transformation</h2><p>Tapestry
uses your class as a starting point. It <em>transforms</em> your class at
runtime. This is necessary for a number of reasons, including to address how
Tapestry shares pages between requests.</p><p>For the most part, these
transformations are both sensible and invisible. In a few limited cases, they
comprise a marginally <a class="external-link"
href="http://www.joelonsoftware.com/printerFriendly/articles/LeakyAbstractions.html";
rel="nofollow">leaky abstraction<
/a> – for instance, the scope restrictions on instance variables
described below – but the programming model in general supports a very
high level of developer productivity.</p><p>Because transformation doesn't
occur until <em>runtime</em>, the build stage of your application is not
affected by the fact that you are creating a Tapestry application. Further,
your classes are absolutely simple POJOs during unit testing.</p><h2
id="ComponentClasses-LiveClassReloading">Live Class Reloading</h2><p>Main
Article: <a href="class-reloading.html">Class Reloading</a></p><p>Component
classes are monitored for changes by the framework. <a
href="class-reloading.html">Classes are reloaded when changed</a>. This allows
you to build your application with a speed approaching that of a scripting
environment, without sacrificing any of the power of the Java
platform.</p><p>And it's fast! You won't even notice that this magic class
reloading has occurred.</p><p>The net result: super p
roductivity — change your class, see the change instantly. This is
designed to be a blend of the best of scripting environments (such as Python or
Ruby) with all the speed and power of Java backing it up.</p><p>However, class
reloading <em>only</em> applies to component classes (pages, components and
mixins) and, starting in 5.2, Tapestry IOC-based service implementations (with
some restrictions). Other classes, such as service interfaces, entity/model
classes, and other data objects, are loaded by the normal class loader and not
subject to live class reloading.</p><h2
id="ComponentClasses-InstanceVariables">Instance Variables</h2><p>Tapestry
components may have instance variables (unlike Tapestry 4, where you had to use
<em>abstract properties</em>).</p><p>Since release 5.3.2, instance variables
may be protected, or package private (that is, no access modifier). Under
specific circumstances they may even be public (public fields must either be
final, or have the @<a class="e
xternal-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Retain.html";>Retain</a> annotation).</p><p><span
style="line-height: 1.4285715;">Be aware that you will need to either provide
getter and setter methods to access your classes' instance variables, or else
annotate the fields with</span><span style="line-height:
1.4285715;"> @</span><a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Property.html";
style="line-height: 1.4285715;">Property</a>.</p><h2
id="ComponentClasses-TransientInstanceVariables">Transient Instance
Variables</h2><p>Unless an instance variable is decorated with an annotation,
it will be a <em>transient</em> instance variable. This means that its value
resets to its default value at the end of reach request (when the <a
href="page-life-cycle.html">page is detached from the request</a>).</p><div
class="confluence-information-macro confluence-information-macr
o-note"><p class="title">About initialization</p><span class="aui-icon
aui-icon-small aui-iconfont-warning
confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>Never initialize an instance field
to a <em>mutable</em> object at the point of declaration. If this is done, the
instance created from that initializer becomes the default value for that field
and is reused inside the component on every request. This could cause state to
inadvertently be shared between different sessions in an
application.</p></div></div>
<div class="confluence-information-macro
confluence-information-macro-warning"><p class="title">Deprecated since
5.2</p><span class="aui-icon aui-icon-small aui-iconfont-error
confluence-information-macro-icon"></span><div
class="confluence-information-macro-body">
</div></div>
<div class="error"><span class="error">Unknown macro: {div}</span>
<p>For Tapestry 5.1 and earlier, in the rare event that you have a variable
that can keep its value between requests and you would like to defeat that
reset logic, then you can add a @<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Retain.html";>Retain</a>
annotation to the field. You should take care that no client-specific data is
stored into such a field, since on a later request the same page
<em>instance</em> may be used for a different user. Likewise, on a later
request for the <em>same</em> client, a <em>different</em> page instance may be
used.</p>
-</div><p>Use <a href="persistent-page-data.html">persistent fields</a> to
hold client-specific information from one request to the next.</p><p>Further,
final fields are (in fact) final, and will not be reset between
requests.</p><h2
id="ComponentClasses-Constructors">Constructors</h2><p>Tapestry will
instantiate your class using the default, no arguments constructor. Other
constructors will be ignored.</p><h2
id="ComponentClasses-Injection">Injection</h2><p>Main Article: <a
href="injection.html">Injection</a></p><p>Injection of dependencies occurs at
the field level, via additional annotations. At runtime, fields that contain
injections become read-only.</p><parameter
ac:name="language">java</parameter><plain-text-body>@Inject // inject a resource
+</div><p>Use <a href="persistent-page-data.html">persistent fields</a> to
hold client-specific information from one request to the next.</p><p>Further,
final fields are (in fact) final, and will not be reset between
requests.</p><h2
id="ComponentClasses-Constructors">Constructors</h2><p>Tapestry will
instantiate your class using the default, no arguments constructor. Other
constructors will be ignored.</p><h2
id="ComponentClasses-Injection">Injection</h2><p>Main Article: <a
href="injection.html">Injection</a></p><p>Injection of dependencies occurs at
the field level, via additional annotations. At runtime, fields that contain
injections become read-only.</p><div class="code panel pdl"
style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">@Inject // inject a resource
private ComponentResources componentResources;
@Inject // inject a block
@@ -105,7 +190,9 @@ private Asset banner;
@Inject // inject a service
private AjaxResponseRenderer ajaxResponseRenderer;
-</plain-text-body><h2 id="ComponentClasses-Parameters">Parameters</h2><p>Main
Article: <a href="component-parameters.html">Component
Parameters</a></p><p>Component parameters are private fields of your component
class annotated with @<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Parameter.html";>Parameter</a>.
Component parameters represent a two-way binding of a field of your component
and a property or resource of its containing component or page.</p><h2
id="ComponentClasses-PersistentFields">Persistent Fields</h2><p>Main Article:
<a href="persistent-page-data.html">Persistent Page Data</a></p><p>Most fields
in component classes are automatically cleared at the end of each request.
However, fields may be annotated so that they retain their value across
requests, using the @<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Persist.html";>Persist</a>
annotation.</p
><h2 id="ComponentClasses-Embedded_ComponentsEmbeddedComponents"><parameter
>ac:name="">Embedded_Components</parameter>Embedded
>Components</h2><p>Components often contain other components. Components
>inside another component's template are called <em>embedded components</em>.
>The containing component's <a href="component-templates.html">template</a>
>will contain special elements, in the Tapestry namespace, identifying where
>the the embedded components go.</p><p>You can define the type of component
>inside template, or you can create an instance variable for the component and
>use the @<a class="external-link"
>href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Component.html";>Component</a>
> annotation to define the component type and
>parameters.</p><p>Example:</p><parameter
>ac:name="language">java</parameter><plain-text-body>package
>org.example.app.pages;
+</pre>
+</div></div><h2 id="ComponentClasses-Parameters">Parameters</h2><p>Main
Article: <a href="component-parameters.html">Component
Parameters</a></p><p>Component parameters are private fields of your component
class annotated with @<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Parameter.html";>Parameter</a>.
Component parameters represent a two-way binding of a field of your component
and a property or resource of its containing component or page.</p><h2
id="ComponentClasses-PersistentFields">Persistent Fields</h2><p>Main Article:
<a href="persistent-page-data.html">Persistent Page Data</a></p><p>Most fields
in component classes are automatically cleared at the end of each request.
However, fields may be annotated so that they retain their value across
requests, using the @<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Persist.html";>Persist</a>
annotation.</p><h2 i
d="ComponentClasses-Embedded_ComponentsEmbeddedComponents"><span
class="confluence-anchor-link"
id="ComponentClasses-Embedded_Components"></span>Embedded
Components</h2><p>Components often contain other components. Components inside
another component's template are called <em>embedded components</em>. The
containing component's <a href="component-templates.html">template</a> will
contain special elements, in the Tapestry namespace, identifying where the the
embedded components go.</p><p>You can define the type of component inside
template, or you can create an instance variable for the component and use the
@<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/Component.html";>Component</a>
annotation to define the component type and parameters.</p><p>Example:</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">package org.example.app.pages;
import org.apache.tapestry5.annotations.Component;
import org.apache.tapestry5.annotations.Property;
@@ -120,7 +207,8 @@ public class Countdown
@Property
private int countValue;
}
-</plain-text-body><p>The above defines a component whose embedded id is
"count" (this id is derived from the name of the field and an element with that
id must be present in the corresponding template, otherwise an error is
displayed (see below)). The type of the component is
org.example.app.components.Count. The start and end parameters of the Count
component are bound to literal values, and the value parameter of the Count
component is bound to the countValue property of the Countdown
component.</p><p>Technically, the start and end parameters should be bound to
properties, just like the value parameter. However, certain literal values,
such as the numeric literals in the example, are accepted by the
<code>prop:</code> binding prefix even though they are not actually properties
(this is largely as a convenience to the application developer). We could also
use the <code>literal:</code> prefix, <code>"start=literal:5"</code>, which
accomplishes largely the same thing.</p><p>You may s
pecify additional parameters inside the component template, but parameters in
the component class take precedence.</p><p><strong>TODO: May want a more
complex check; what if user uses prop: in the template and there's a
conflict?</strong></p><p>You may override the default component id (as derived
from the field name) using the id() attribute of the Component
annotation.</p><p>If you define a component in the component class, and there
is no corresponding element in the template, Tapestry will log an error. In the
example above that would be the case if the template for the Countdown page
didn't contain an element with <code><t:count
t:id="count"></code>.</p></div>
+</pre>
+</div></div><p>The above defines a component whose embedded id is "count"
(this id is derived from the name of the field and an element with that id must
be present in the corresponding template, otherwise an error is displayed (see
below)). The type of the component is org.example.app.components.Count. The
start and end parameters of the Count component are bound to literal values,
and the value parameter of the Count component is bound to the countValue
property of the Countdown component.</p><p>Technically, the start and end
parameters should be bound to properties, just like the value parameter.
However, certain literal values, such as the numeric literals in the example,
are accepted by the <code>prop:</code> binding prefix even though they are not
actually properties (this is largely as a convenience to the application
developer). We could also use the <code>literal:</code> prefix,
<code>"start=literal:5"</code>, which accomplishes largely the same
thing.</p><p>You may specify
additional parameters inside the component template, but parameters in the
component class take precedence.</p><p><strong>TODO: May want a more complex
check; what if user uses prop: in the template and there's a
conflict?</strong></p><p>You may override the default component id (as derived
from the field name) using the id() attribute of the Component
annotation.</p><p>If you define a component in the component class, and there
is no corresponding element in the template, Tapestry will log an error. In the
example above that would be the case if the template for the Countdown page
didn't contain an element with <code><t:count
t:id="count"></code>.</p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/component-events-faq.html
==============================================================================
--- websites/production/tapestry/content/component-events-faq.html (original)
+++ websites/production/tapestry/content/component-events-faq.html Wed Sep 20
12:29:16 2017
@@ -27,6 +27,16 @@
</title>
<link type="text/css" rel="stylesheet" href="/resources/space.css" />
+ <link href='/resources/highlighter/styles/shCoreCXF.css'
rel='stylesheet' type='text/css' />
+ <link href='/resources/highlighter/styles/shThemeCXF.css' rel='stylesheet'
type='text/css' />
+ <script src='/resources/highlighter/scripts/shCore.js'
type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushJava.js'
type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushXml.js'
type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushPlain.js'
type='text/javascript'></script>
+ <script>
+ SyntaxHighlighter.defaults['toolbar'] = false;
+ SyntaxHighlighter.all();
+ </script>
<link href="/styles/style.css" rel="stylesheet" type="text/css"/>
@@ -67,7 +77,7 @@
</div>
<div id="content">
- <div
id="ConfluenceContent"><plain-text-body>{scrollbar}</plain-text-body>
+ <div id="ConfluenceContent">
<h2 id="ComponentEventsFAQ-ComponentEvents">Component Events </h2>
@@ -98,8 +108,7 @@
<h3
id="ComponentEventsFAQ-IspecifiedazoneinmyActionLink/EventLink,sowhydoesn'tmyeventfireviaajax(request.isXHR()isfalse)?">I
specified a zone in my ActionLink/EventLink, so why doesn't my event fire via
ajax (request.isXHR() is false)?</h3>
<p>Check your browser's JavaScript console for errors. It's likely that a
JavaScript error has prevented Tapestry from transforming your
ActionLink/EventLink from a page render action to an ajax action.</p>
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-<plain-text-body>{scrollbar}</plain-text-body></div>
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![http://tapestry.apache.org/images/tapestry_small.png"](http://tapestry.apache.org/images/tapestry_small.png"){kind=link}