Author: buildbot
Date: Sat Aug 1 22:19:41 2015
New Revision: 960460
Log:
Production update by buildbot for tapestry
Modified:
websites/production/tapestry/content/cache/main.pageCache
websites/production/tapestry/content/component-events.html
websites/production/tapestry/content/css.html
websites/production/tapestry/content/forms-and-validation.html
Modified: websites/production/tapestry/content/cache/main.pageCache
==============================================================================
Binary files - no diff available.
Modified: websites/production/tapestry/content/component-events.html
==============================================================================
--- websites/production/tapestry/content/component-events.html (original)
+++ websites/production/tapestry/content/component-events.html Sat Aug 1
22:19:41 2015
@@ -133,11 +133,11 @@
</div>
</li></ul>
-</div><p>Let's review a simple example. Here's a portion of the template for a
page (let's call it "Chooser") that lets the user choose a number between 1 and
10:</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeContent panelContent pdl">
+</div><p>Let's review a simple example. Here's a portion of the template for a
page (let's call it "Chooser") that lets the user choose a number between 1 and
10:</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeHeader panelHeader pdl" style="border-bottom-width:
1px;"><b>Chooser.tml (partial)</b></div><div class="codeContent panelContent
pdl">
<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><p> Choose a number from 1 to 10:
<t:count end="10" value="index">
- <a t:id="select" t:type="actionlink"
context="index">${index}</t:comp>
+ <a t:id="select" t:type="actionlink"
context="index">${index}</a>
</t:count>
</p>
</pre>
Modified: websites/production/tapestry/content/css.html
==============================================================================
--- websites/production/tapestry/content/css.html (original)
+++ websites/production/tapestry/content/css.html Sat Aug 1 22:19:41 2015
@@ -114,7 +114,7 @@
</div>
</li></ul>
-</div><p>Tapestry includes sophisticated support for CSS in the form of
annotation-based linking, far-future expire headers, automatic duplicate
removal, and other features provided for <a shape="rect"
href="assets.html">assets</a>.</p><h2 id="CSS-Defaultstylesheet">Default style
sheet</h2><p>Tapestry includes a built-in style sheet, tapestry.css, in all
HTML documents (documents that have an outer <html> element and a nested
<head> element), as part of the "core" JavaScript stack. The core
JavaScript stack also includes the CSS for <a shape="rect"
class="external-link" href="http://getbootstrap.com/"; >Bootstrap
3.1.1</a>.</p><h2 id="CSS-AddingyourownCSS">Adding your own CSS</h2><p>A page
or component (for example, a <a shape="rect"
href="layout-component.html">layout component</a>) that is rendering the
<head> tag can add a style sheet directly in the markup.</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
+</div><p>Tapestry includes sophisticated support for CSS in the form of
annotation-based linking, far-future expire headers, automatic duplicate
removal, and other features provided for <a shape="rect"
href="assets.html">assets</a>.</p><h2 id="CSS-Defaultstylesheet">Default style
sheet</h2><p>Tapestry includes a built-in style sheet, tapestry.css, in all
HTML documents (documents that have an outer <html> element and a nested
<head> element), as part of the "core" JavaScript stack. For Tapestry 5.4
and later, the core JavaScript stack also includes the CSS for <a shape="rect"
class="external-link" href="http://getbootstrap.com/"; >Bootstrap
3.1.1</a>.</p><h2 id="CSS-AddingyourownCSS">Adding your own CSS</h2><p>A page
or component (for example, a <a shape="rect"
href="layout-component.html">layout component</a>) that is rendering the
<head> tag can add a style sheet directly in the markup.</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeCont
ent panelContent pdl">
<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;"><head>
<link href="/css/site.css" rel="stylesheet" type="text/css"/>
. . .
Modified: websites/production/tapestry/content/forms-and-validation.html
==============================================================================
--- websites/production/tapestry/content/forms-and-validation.html (original)
+++ websites/production/tapestry/content/forms-and-validation.html Sat Aug 1
22:19:41 2015
@@ -107,17 +107,16 @@
</div>
</li></ul>
</div><p> </p><p>Tapestry provides support for creating and rendering
forms, populating their fields, and validating user input. For simple cases,
input validation is declarative, meaning you simply tell Tapestry what
validations to apply to a given field, and it takes care of it on the server
and (optionally) on the client as well. In addition, you can provide event
handler methods in your page or component classes to handle more complex
validation scenarios.</p><p>Finally, Tapestry not only makes it easy to present
errors messages to the user, but it can also automatically highlight form
fields when validation fails.</p><p><strong>Contents</strong></p><p><style
type="text/css">/*<![CDATA[*/
-div.rbtoc1438463978457 {padding: 0px;}
-div.rbtoc1438463978457 ul {list-style: disc;margin-left: 0px;}
-div.rbtoc1438463978457 li {margin-left: 0px;padding-left: 0px;}
+div.rbtoc1438467572974 {padding: 0px;}
+div.rbtoc1438467572974 ul {list-style: disc;margin-left: 0px;}
+div.rbtoc1438467572974 li {margin-left: 0px;padding-left: 0px;}
-/*]]>*/</style></p><div class="toc-macro rbtoc1438463978457">
+/*]]>*/</style></p><div class="toc-macro rbtoc1438467572974">
<ul class="toc-indentation"><li>Related Articles</li></ul>
-<ul><li><a shape="rect" href="#FormsandValidation-TheFormComponent">The Form
Component</a>
-<ul class="toc-indentation"><li><a shape="rect"
href="#FormsandValidation-FormEvents">Form Events</a></li><li><a shape="rect"
href="#FormsandValidation-HandlingEvents">Handling Events</a></li><li><a
shape="rect" href="#FormsandValidation-TrackingValidationErrors">Tracking
Validation Errors</a></li><li><a shape="rect"
href="#FormsandValidation-StoringDataBetweenRequests">Storing Data Between
Requests</a></li><li><a shape="rect"
href="#FormsandValidation-ConfiguringFieldsandLabels">Configuring Fields and
Labels</a></li><li><a shape="rect"
href="#FormsandValidation-CentralizingValidationwith@Validate">Centralizing
Validation with @Validate</a></li><li><a shape="rect"
href="#FormsandValidation-ServerSideValidation">Server Side
Validation</a></li><li><a shape="rect"
href="#FormsandValidation-CustomizingValidationMessages">Customizing Validation
Messages</a>
+<ul><li><a shape="rect" href="#FormsandValidation-TheFormComponent">The Form
Component</a></li><li><a shape="rect"
href="#FormsandValidation-FormEvents">Form Events</a></li><li><a shape="rect"
href="#FormsandValidation-HandlingEvents">Handling Events</a></li><li><a
shape="rect" href="#FormsandValidation-TrackingValidationErrors">Tracking
Validation Errors</a></li><li><a shape="rect"
href="#FormsandValidation-StoringDataBetweenRequests">Storing Data Between
Requests</a></li><li><a shape="rect"
href="#FormsandValidation-ConfiguringFieldsandLabels">Configuring Fields and
Labels</a></li><li><a shape="rect"
href="#FormsandValidation-CentralizingValidationwith@Validate">Centralizing
Validation with @Validate</a></li><li><a shape="rect"
href="#FormsandValidation-ServerSideValidation">Server Side
Validation</a></li><li><a shape="rect"
href="#FormsandValidation-CustomizingValidationMessages">Customizing Validation
Messages</a>
<ul class="toc-indentation"><li><a shape="rect"
href="#FormsandValidation-CustomizingValidationMessagesforBeanEditForm">Customizing
Validation Messages for BeanEditForm</a></li></ul>
</li><li><a shape="rect"
href="#FormsandValidation-ConfiguringValidatorContraintsintheMessageCatalog">Configuring
Validator Contraints in the Message Catalog</a></li><li><a shape="rect"
href="#FormsandValidation-ValidationMacros">Validation Macros</a></li><li><a
shape="rect"
href="#FormsandValidation-OverridingtheTranslatorwithEvents">Overriding the
Translator with Events</a></li></ul>
-</li></ul></div><h1 id="FormsandValidation-TheFormComponent">The Form
Component</h1><p>The core of Tapestry's form support is the <a shape="rect"
class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/Form.html";>Form</a>
component. The Form component encloses (wraps around) all the other <em>field
components</em> such as <a shape="rect" class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/TextField.html";>TextField</a>,
<a shape="rect" class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/TextArea.html";>TextArea</a>,
<a shape="rect" class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/Checkbox.html";>Checkbox</a>,
etc.</p><h2 id="FormsandValidation-FormEvents">Form Events</h2><p>The Form
component emits a number of <a shape="rect" href="component-events.html">
component events</a>. You'll want to provide event handler methods for some of
these.</p><p>When rendering, the Form component emits two events: first,
"prepareForRender", then "prepare". These allow the Form's container to set up
any fields or properties that will be referenced in the form. For example, this
is a good place to create a temporary entity object to be rendered, or to load
an entity from a database to be edited.</p><p>When user submits the form on the
client, a series of steps occur on the server.</p><p>First, the Form emits a
"prepareForSubmit" event, then a "prepare" event. These allow the container to
ensure that objects are set up and ready to receive information from the form
submission.</p><p>Next, all the fields inside the form are <em>activated</em>
to pull values out of the incoming request, validate them and (if valid) store
the changes.</p><div class="navmenu" style="float:right; width:25%;
background:#eee; margin:3px; padding:3px">
+</div><h2 id="FormsandValidation-TheFormComponent">The Form
Component</h2><p>The core of Tapestry's form support is the <a shape="rect"
class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/Form.html";>Form</a>
component. The Form component encloses (wraps around) all the other <em>field
components</em> such as <a shape="rect" class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/TextField.html";>TextField</a>,
<a shape="rect" class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/TextArea.html";>TextArea</a>,
<a shape="rect" class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/Checkbox.html";>Checkbox</a>,
etc.</p><h2 id="FormsandValidation-FormEvents">Form Events</h2><p>The Form
component emits a number of <a shape="rect"
href="component-events.html">component
events</a>. You'll want to provide event handler methods for some of
these.</p><p>When rendering, the Form component emits two events: first,
"prepareForRender", then "prepare". These allow the Form's container to set up
any fields or properties that will be referenced in the form. For example, this
is a good place to create a temporary entity object to be rendered, or to load
an entity from a database to be edited.</p><p>When user submits the form on the
client, a series of steps occur on the server.</p><p>First, the Form emits a
"prepareForSubmit" event, then a "prepare" event. These allow the container to
ensure that objects are set up and ready to receive information from the form
submission.</p><p>Next, all the fields inside the form are <em>activated</em>
to pull values out of the incoming request, validate them and (if valid) store
the changes.</p><div class="navmenu" style="float:right; width:25%;
background:#eee; margin:3px; padding:3px">
<p><em>For Tapestry 4 Users:</em> Tapestry 5 does not use the fragile "form
rewind" approach from Tapestry 4. Instead, a hidden field generated during the
render stores the information needed to process the form
submission.</p></div> <p>After the fields have done their processing, the
Form emits a "validate" event. This is your chance to perform any cross-form
validation that can't be described declaratively.</p><p>Next, the Form
determines if there have been any validation errors. If there have been, then
the submission is considered a failure, and a "failure" event is emitted. If
there have been no validation errors, then a "success" event is
emitted.</p><p>Finally, the Form emits a "submit" event, for logic that doesn't
care about success or failure.</p><div class="table-wrap"><table
class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1"
class="confluenceTh"><p>Form Event (in order)</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>Phase</p></th><th colspan
="1" rowspan="1" class="confluenceTh"><p>When emitted (and typical
use)</p></th><th colspan="1" rowspan="1" class="confluenceTh">Method
Name</th><th colspan="1" rowspan="1" class="confluenceTh">@OnEvent
Constant</th></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p><strong>prepareForRender</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Render</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Before rendering the form (e.g. load an
entity from a database to be edited)</p></td><td colspan="1" rowspan="1"
class="confluenceTd">onPrepareForRender()</td><td colspan="1" rowspan="1"
class="confluenceTd">EventConstants.PREPARE_FOR_RENDER</td></tr><tr><td
colspan="1" rowspan="1"
class="confluenceTd"><p><strong>prepare</strong></p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Render</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Before rendering the form, but after
<em>prepareForRender</em></p></td><td colspan="1" rowspan="1" c
lass="confluenceTd">onPrepare()</td><td colspan="1" rowspan="1"
class="confluenceTd">EventConstants.PREPARE</td></tr><tr><td colspan="1"
rowspan="1"
class="confluenceTd"><p><strong>prepareForSubmit</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Submit</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Before the submitted form is
processed</p></td><td colspan="1" rowspan="1"
class="confluenceTd">onPrepareForSubmit()</td><td colspan="1" rowspan="1"
class="confluenceTd">EventConstants.PREPARE_FOR_SUBMIT</td></tr><tr><td
colspan="1" rowspan="1"
class="confluenceTd"><p><strong>prepare</strong></p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Submit</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>Before the submitted form is processed, but after
<em>prepareForSubmit</em></p></td><td colspan="1" rowspan="1"
class="confluenceTd">onPrepare()</td><td colspan="1" rowspan="1"
class="confluenceTd">EventConstants.PREPARE</td></tr><tr><td cols
pan="1" rowspan="1"
class="confluenceTd"><p><strong>validate</strong></p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Submit</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>After fields have been populated from submitted values
and validated (e.g. perform cross-field validation)</p></td><td colspan="1"
rowspan="1" class="confluenceTd">onValidate</td><td colspan="1" rowspan="1"
class="confluenceTd">EventConstants.VALIDATE</td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p><strong>validateForm</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Submit</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>same as <em>validate (deprecated – do
not use)<br clear="none"></em></p></td><td colspan="1" rowspan="1"
class="confluenceTd"><em>onValidateForm</em></td><td colspan="1" rowspan="1"
class="confluenceTd"> </td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p><strong>failure</strong></p></td><td colspan=
"1" rowspan="1" class="confluenceTd"><p>Submit</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>After one or more validation errors have
occurred</p></td><td colspan="1" rowspan="1"
class="confluenceTd">onFailure()</td><td colspan="1" rowspan="1"
class="confluenceTd">EventConstants.FAILURE</td></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p><strong>success</strong></p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>Submit</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>When validation has completed
<em>without</em> any errors (e.g. save changes to the database)</p></td><td
colspan="1" rowspan="1" class="confluenceTd">onSuccess()</td><td colspan="1"
rowspan="1" class="confluenceTd">EventConstants.SUCCESS</td></tr><tr><td
colspan="1" rowspan="1"
class="confluenceTd"><p><strong>submit</strong></p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>Submit</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>After all validation (s
uccess or failure) has finished</p></td><td colspan="1" rowspan="1"
class="confluenceTd">onSubmit()</td><td colspan="1" rowspan="1"
class="confluenceTd">EventConstants.SUBMIT</td></tr></tbody></table></div><p>Note
that the "prepare" event is emitted during both form rendering and form
submission.</p><h2 id="FormsandValidation-HandlingEvents">Handling
Events</h2><p>Main Article: <a shape="rect"
href="component-events.html">Component Events</a></p><p>You handle events by
providing methods in your page or component class, either following the
on<strong><em>Event</em></strong>From<strong><em>Component</em></strong>()
naming convention or using the OnEvent annotation. For example:</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeHeader
panelHeader pdl" style="border-bottom-width: 1px;"><b>Event Handler Using
Naming Convention</b></div><div class="codeContent panelContent pdl">
<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;"> void onValidateFromPassword() { ...}</pre>
</div></div><p>or the equivalent using @OnEvent:</p><div class="code panel
pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl"
style="border-bottom-width: 1px;"><b>Event Handler Using @OnEvent
Annotation</b></div><div class="codeContent panelContent pdl">
@@ -125,7 +124,7 @@ div.rbtoc1438463978457 li {margin-left:
void verifyThePassword() { ...}</pre>
</div></div><h2 id="FormsandValidation-TrackingValidationErrors">Tracking
Validation Errors</h2><p>Associated with the Form is a <a shape="rect"
class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/ValidationTracker.html";>ValidationTracker</a>
that tracks all the provided user input and validation errors for every field
in the form. The tracker can be provided to the Form via the Form's tracker
parameter, but this is rarely necessary.</p><p>The Form includes methods
<code>isValid()</code> and <code>getHasErrors()</code>, which are used to see
if the Form's validation tracker contains any errors.</p><p>In your own logic,
it is possible to record your own errors. Form includes two different versions
of method <code>recordError()</code>, one of which specifies a <a shape="rect"
class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/Field.html";>Field</a>
(an interface implemented by all form element components),
and one of which is for "global" errors, not associated with any particular
field. If the error concerns only a single field, you should use the first
version so that the field will be highlighted.</p><h2
id="FormsandValidation-StoringDataBetweenRequests">Storing Data Between
Requests</h2><p></p><div class="navmenu" style="float:right; width:40%;
background:white; margin:3px; padding:3px">
<div class="confluence-information-macro
confluence-information-macro-information"><p class="title">New in Tapestry
5.4</p><span class="aui-icon aui-icon-small aui-iconfont-info
confluence-information-macro-icon"></span><div
class="confluence-information-macro-body">
-<p>Starting in Tapestry 5.4, the default behavior for server-side validation
failures is to re-render the page within the same request (rather than emitting
a redirect). This removes the need to use a session-persistent field to store
the validation tracker when validation failures occur.</p></div></div></div>As
with other action requests, the result of a form submission (except when using
<a shape="rect" href="ajax-and-zones.html">Zones</a>) is to send a redirect to
the client, which results in a second request (to re-render the page). The
ValidationTracker must be <a shape="rect"
href="persistent-page-data.html">persisted</a> (generally in the HttpSession)
across these two requests in order to prevent the loss of validation
information. Fortunately, the default ValidationTracker provided by the Form
component is persistent, so you don't normally have to worry about
it.<p>However, for the same reason, the individual fields updated by the
components should also be persisted across r
equests, and this is something you <strong>do</strong> need to do yourself
– generally with the @Persist annotation.</p><p>For example, a Login
page, which collects a user name and a password, might look like:</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
+<p>Starting in Tapestry 5.4, the default behavior for server-side validation
failures is to re-render the page within the same request (rather than emitting
a redirect). This removes the need to use a session-persistent field to store
the validation tracker when validation failures occur.</p></div></div></div>As
with other action requests, the result of a form submission (except when using
<a shape="rect" href="ajax-and-zones.html">Zones</a>) is to send a redirect to
the client, which results in a second request (to re-render the page). The
ValidationTracker must be <a shape="rect"
href="persistent-page-data.html">persisted</a> (generally in the HttpSession)
across these two requests in order to prevent the loss of validation
information. Fortunately, the default ValidationTracker provided by the Form
component is persistent, so you don't normally have to worry about
it.<p>However, for the same reason, the individual fields updated by the
components should also be persisted across r
equests, and this is something you <strong>do</strong> need to do yourself
– generally with the @Persist annotation.</p><p>For example, a Login page
class, which collects a user name and a password, might look like:</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeHeader
panelHeader pdl" style="border-bottom-width: 1px;"><b>Login.java
Example</b></div><div class="codeContent panelContent pdl">
<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">package com.example.newapp.pages;
@@ -175,7 +174,7 @@ public class Login {
</pre>
</div></div><p></p><div class="navmenu" style="float:right; width:40%;
background:white; margin:3px; padding:3px">
<div class="confluence-information-macro
confluence-information-macro-information"><span class="aui-icon aui-icon-small
aui-iconfont-info confluence-information-macro-icon"></span><div
class="confluence-information-macro-body">
-<p>Note that the onValidateFromLoginForm() and onSuccess() methods are not
public; event handler methods can have any visibility, even private. Package
private (that is, no modifier) is the typical use, as it allows the component
to be tested, from a test case class in the same
package.</p></div></div></div>Because a form submission is really <em>two</em>
requests: the submission itself (which results in a redirect response), then a
second request for the page (which results in a re-rendering of the page), it
is necessary to persist the userName field between the two requests, by using
the @Persist annotation. This would be necessary for the password field as
well, except that the <a shape="rect" class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/PasswordField.html";>PasswordField</a>
component never renders a value.<div class="confluence-information-macro
confluence-information-macro-tip"><span class="aui-icon aui-icon-smal
l aui-iconfont-approve confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>To avoid data loss, fields whose
values are stored in the HttpSession (such as userName, above) must be
serializable, particularly if you want to be able to cluster your application
or preserve sessions across server restarts.</p></div></div><p>The Form only
emits a "success" event if the there are no prior validation errors. This means
it is not necessary to write <code>if (form.getHasErrors()) return;</code> as
the first line of the method.</p><p>Finally, notice how business logic fits
into validation. The UserAuthenticator service is responsible for ensuring that
the userName and (plaintext) password are valid. When it returns false, we ask
the Form component to record an error. We provide the PasswordField instance as
the first parameter; this ensures that the password field, and its label, are
decorated when the Form is re-rendered, to present the errors to the use
r.</p><h2 id="FormsandValidation-ConfiguringFieldsandLabels">Configuring
Fields and Labels</h2><p>The template for the Login page contains a minimal
amount of Tapestry instrumentation and references some of the <a shape="rect"
class="external-link" href="http://getbootstrap.com"; >Bootstrap</a> CSS classes
(Bootstrap is automatically integrated into each Tapestry page):</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
+<p>Note that the onValidateFromLoginForm() and onSuccess() methods are not
public; event handler methods can have any visibility, even private. Package
private (that is, no modifier) is the typical use, as it allows the component
to be tested, from a test case class in the same
package.</p></div></div></div>Because a form submission is really <em>two</em>
requests: the submission itself (which results in a redirect response), then a
second request for the page (which results in a re-rendering of the page), it
is necessary to persist the userName field between the two requests, by using
the @Persist annotation. This would be necessary for the password field as
well, except that the <a shape="rect" class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/PasswordField.html";>PasswordField</a>
component never renders a value.<div class="confluence-information-macro
confluence-information-macro-tip"><span class="aui-icon aui-icon-smal
l aui-iconfont-approve confluence-information-macro-icon"></span><div
class="confluence-information-macro-body"><p>To avoid data loss, fields whose
values are stored in the HttpSession (such as userName, above) must be
serializable, particularly if you want to be able to cluster your application
or preserve sessions across server restarts.</p></div></div><p>The Form only
emits a "success" event if the there are no prior validation errors. This means
it is not necessary to write <code>if (form.getHasErrors()) return;</code> as
the first line of the method.</p><p>Finally, notice how business logic fits
into validation. The UserAuthenticator service is responsible for ensuring that
the userName and (plaintext) password are valid. When it returns false, we ask
the Form component to record an error. We provide the PasswordField instance as
the first parameter; this ensures that the password field, and its label, are
decorated when the Form is re-rendered, to present the errors to the use
r.</p><h2 id="FormsandValidation-ConfiguringFieldsandLabels">Configuring
Fields and Labels</h2><p>The Login page template below contains a minimal
amount of Tapestry instrumentation and references some of the <a shape="rect"
class="external-link" href="http://getbootstrap.com"; >Bootstrap</a> CSS classes
(Bootstrap is automatically integrated into each page by default, starting with
Tapestry 5.4).</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeHeader panelHeader pdl" style="border-bottom-width:
1px;"><b>Login.tml Example</b></div><div class="codeContent panelContent pdl">
<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><html t:type="layout" title="newapp com.example"
xmlns:t="http://tapestry.apache.org/schema/tapestry_5_4.xsd">
@@ -192,7 +191,7 @@ public class Login {
</html>
</pre>
-</div></div><p>Rendering the page gives a reasonable pleasing first
pass:</p><p><span class="confluence-embedded-file-wrapper image-center-wrapper
confluence-embedded-manual-size"><img class="confluence-embedded-image
confluence-content-image-border image-center" width="500"
src="forms-and-validation.data/newapp_com_example.png"></span></p><p>The
Tapestry Form component is responsible for creating the necessary URL for the
form submission (this is Tapestry's responsibility, not yours).</p><p><span
style="line-height: 1.4285715;">For the TextField, we provide a component id,
userName. We could specify the </span><code style="line-height:
1.4285715;">value</code><span style="line-height: 1.4285715;"> parameter, but
the default is to match the TextField's id against a property of the container,
the Login page, if such a property exists. </span></p><p>As a rule of
thumb, you should always give your fields a specific id (this id will be used
to generate the <code>name</code> and <co
de>id</code> attributes of the rendered tag). Being allowed to omit the value
parameter helps to keep the template from getting too cluttered.</p><p>The
FormGroup mixin decorates the field with some additional markup, including a
<label> element; this leverages more of Bootstrap.</p><div class="code
panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl"
style="border-bottom-width: 1px;"><b>userName component as
rendered</b></div><div class="codeContent panelContent pdl">
+</div></div><p>Rendering the page gives a reasonably pleasing first
pass:</p><p><span class="confluence-embedded-file-wrapper image-center-wrapper
confluence-embedded-manual-size"><img class="confluence-embedded-image
confluence-content-image-border image-center" width="500"
src="forms-and-validation.data/newapp_com_example.png"></span></p><p>The
Tapestry Form component is responsible for creating the necessary URL for the
form submission (this is Tapestry's responsibility, not yours).</p><p><span
style="line-height: 1.4285715;">For the TextField, we provide a component id,
userName. We could specify the </span><code style="line-height:
1.4285715;">value</code><span style="line-height: 1.4285715;"> parameter, but
the default is to match the TextField's id against a property of the container,
the Login page, if such a property exists. </span></p><p>As a rule of
thumb, you should always give your fields a specific id (this id will be used
to generate the <code>name</code> and <co
de>id</code> attributes of the rendered tag). Being allowed to omit the value
parameter helps to keep the template from getting too cluttered.</p><p>The
FormGroup mixin decorates the field with some additional markup, including a
<label> element; this leverages more of Bootstrap.</p><div class="code
panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl"
style="border-bottom-width: 1px;"><b>userName component as
rendered</b></div><div class="codeContent panelContent pdl">
<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><div class="form-group">
<label for="userName" class="control-label">User Name</label>
<input id="userName" class="form-control" name="userName" type="text">
