Author: bobharner
Date: Sat Nov 4 16:12:02 2017
New Revision: 1020446
Log:
Manually restoring old version as a work-around for INFRA-14971
Modified:
websites/production/tapestry/content/ajax-and-zones.html
Modified: websites/production/tapestry/content/ajax-and-zones.html
==============================================================================
--- websites/production/tapestry/content/ajax-and-zones.html (original)
+++ websites/production/tapestry/content/ajax-and-zones.html Sat Nov 4
16:12:02 2017
@@ -27,6 +27,17 @@
</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/shBrushJScript.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"/>
@@ -67,12 +78,111 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><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 ("ajax","javascript") and
space = currentSpace()</parameter></rich-text-body><p>Tapestry provides
easy-to-use support for <strong>Ajax</strong>, the technique of using
JavaScript to dynamically update parts of a web page with content from the
server without redrawing the whole page. With Tapestry, you can do simple Ajax
updates without having to write any JavaScript code at all.</p><p>Ajax support
is included in many <a href="component-reference.html">built-in components</a>
and <a href="component-mixins.html">component mixins</a> via
the <code>async</code> parameter (in Tapestry 5.4+
) and the <code>zone</code> parameter (for earlier versions). Here we use
an EventLink component to trigger an Ajax update of another area of the
page:</p><parameter ac:name="language">xml</parameter><parameter
ac:name="title">Page or component template
(partial)</parameter><plain-text-body><t:eventlink event="updateTime"
async="true">update</t:eventlink>
+ <div id="ConfluenceContent"><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="ajax-and-zones.html">Ajax and Zones</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="legacy-javascript.html">Legacy JavaScript</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="coffeescript.html">CoffeeScript</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="client-side-javascript.html">Client-Side
JavaScript</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="javascript-modules.html">JavaScript
Modules</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="javascript-faq.html">JavaScript 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="ajax-components-faq.html">Ajax Components
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-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="assets.html">Assets</a>
+
+
+ </div>
+ </li></ul>
+</div>
+
+
+<p>Tapestry provides easy-to-use support for <strong>Ajax</strong>, the
technique of using JavaScript to dynamically update parts of a web page with
content from the server without redrawing the whole page. With Tapestry, you
can do simple Ajax updates without having to write any JavaScript code at
all.</p><p>Ajax support is included in many <a
href="component-reference.html">built-in components</a> and <a
href="component-mixins.html">component mixins</a> via
the <code>async</code> parameter (in Tapestry 5.4+) and
the <code>zone</code> parameter (for earlier versions). Here we use an
EventLink component to trigger an Ajax update of another area of the
page:</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>Page or
component template (partial)</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><t:eventlink event="updateTime"
async="true">update</t:eventlink>
...
<t:zone t:id="timeArea" id="timeArea">
The current time is ${currentTime}
</t:zone>
-</plain-text-body><p>The corresponding Java code might look like
this:</p><parameter ac:name="language">java</parameter><parameter
ac:name="title">Page or component class
(partial)</parameter><plain-text-body>@Inject
+</pre>
+</div></div><p>The corresponding Java code might look like this:</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeHeader
panelHeader pdl" style="border-bottom-width: 1px;"><b>Page or component class
(partial)</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">@Inject
private AjaxResponseRenderer ajaxResponseRenderer;
@InjectComponent
@@ -86,10 +196,11 @@ void onUpdateTime()
{
currentTime = new Date();
 ajaxResponseRenderer.addRender(timeArea);
-} </plain-text-body><p>That <code>onUpdateTime</code> method is just an
ordinary Tapestry event handler, except that it uses an injected
<code>AjaxResponseRenderer</code> to tell Tapestry what zone to update when the
link is clicked.</p><p>Since Tapestry 5.4.2, you can also easily invoke
server-side event handlers using the <code>@PublishEvents</code>
annotation and the <code>t5/core/ajax</code> JavaScript function, as
explained in the "<span style="font-size: 14.0px;">Invoking server-side event
handler methods from JavaScript" section below.</span></p><h3
id="AjaxandZones-Zones">Zones</h3><p>Zones are Tapestry's approach to
performing partial page updates. A <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/Zone.html">Zone
component</a> renders as an HTML element, typically a <div>, and serves
as a marker for where dynamically-updated content should be replaced. A zone is
recognizable in the DOM b
ecause it will have the attribute <code>data-container-type=zone</code>.
The client-side support for Zones is keyed off of this attribute and
value.</p><p>Starting in Tapestry 5.4 you can use any HTML element in your
template as a zone marker, by passing its client-side id to the two-argument
version of the addRender method.</p><p><span style="line-height: 1.4285715;">A
Zone updated can be triggered by an EventLink, ActionLink or Select component,
or by a Form. All of these components support the <code>async</code> and/or
<code>zone</code> parameters. Clicking such a link will invoke an event handler
method on the server as normal ... except that a </span><em style="line-height:
1.4285715;">partial page response</em><span style="line-height: 1.4285715;"> is
sent to the client, and the content of that response is used to update the
Zone's <div> in
place.</span><plain-text-body>{float:right|background=#eee|padding=0 1em}
- *JumpStart Demo:*
- [AJAX
ActionLink|http://jumpstart.doublenegative.com.au/jumpstart/examples/ajax/actionlink]
-{float}</plain-text-body></p><h3
id="AjaxandZones-EventHandlerReturnTypes">Event Handler Return Types</h3><p>In
a traditional request, the return value of an event handler method may used to
determine which page will render a <em>complete</em> response, and a
<em>redirect</em> may sent to the client to render the new page (as a new
request).</p><p>In contrast, with a Zone update, the return value may used to
render a <em>partial response</em> within the <em>same
request</em>.</p><rich-text-body><p>Starting in Tapestry 5.3, Ajax event
handlers typically have a void return type and use AjaxResponseRenderer to
indicate which zone to update. The AjaxResponseRender approach means that
the <code>zone</code> parameter's value (oridinarily indicating which zone
to update) is no longer needed. Tapestry 5.4 introduced
the <code>async="true"</code> parameter to avoid having to redundantly
indicate which zone to update.</p></rich-text-body><p>If you only have one zone
to update and do
n't want to use AjaxResponseRenderer, you can instead return a value from your
event handler method. The simplest case is just to return the zone's own
body:</p><parameter ac:name="language">java</parameter><plain-text-body>@Inject
+} </pre>
+</div></div><p>That <code>onUpdateTime</code> method is just an ordinary
Tapestry event handler, except that it uses an injected
<code>AjaxResponseRenderer</code> to tell Tapestry what zone to update when the
link is clicked.</p><p>Since Tapestry 5.4.2, you can also easily invoke
server-side event handlers using the <code>@PublishEvents</code>
annotation and the <code>t5/core/ajax</code> JavaScript function, as
explained in the "<span style="font-size: 14.0px;">Invoking server-side event
handler methods from JavaScript" section below.</span></p><h3
id="AjaxandZones-Zones">Zones</h3><p>Zones are Tapestry's approach to
performing partial page updates. A <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/Zone.html">Zone
component</a> renders as an HTML element, typically a <div>, and serves
as a marker for where dynamically-updated content should be replaced. A zone is
recognizable in the DOM because i
t will have the attribute <code>data-container-type=zone</code>. The
client-side support for Zones is keyed off of this attribute and
value.</p><p>Starting in Tapestry 5.4 you can use any HTML element in your
template as a zone marker, by passing its client-side id to the two-argument
version of the addRender method.</p><p><span style="line-height: 1.4285715;">A
Zone updated can be triggered by an EventLink, ActionLink or Select component,
or by a Form. All of these components support the <code>async</code> and/or
<code>zone</code> parameters. Clicking such a link will invoke an event handler
method on the server as normal ... except that a </span><em style="line-height:
1.4285715;">partial page response</em><span style="line-height: 1.4285715;"> is
sent to the client, and the content of that response is used to update the
Zone's <div> in place.</span></p><div class="navmenu" style="float:right;
background:#eee; margin:3px; padding:0 1em">
+<p> <strong>JumpStart Demo:</strong><br clear="none">
+ <a class="external-link"
href="http://jumpstart.doublenegative.com.au/jumpstart/examples/ajax/actionlink"
rel="nofollow">AJAX ActionLink</a></p></div><h3
id="AjaxandZones-EventHandlerReturnTypes">Event Handler Return Types</h3><p>In
a traditional request, the return value of an event handler method may used to
determine which page will render a <em>complete</em> response, and a
<em>redirect</em> may sent to the client to render the new page (as a new
request).</p><p>In contrast, with a Zone update, the return value may used to
render a <em>partial response</em> within the <em>same request</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>Starting in Tapestry 5.3, Ajax
event handlers typically have a void return type and use AjaxResponseRenderer
to indicate which zone to update. The AjaxResponseRe
nder approach means that the <code>zone</code> parameter's value
(oridinarily indicating which zone to update) is no longer needed. Tapestry 5.4
introduced the <code>async="true"</code> parameter to avoid having to
redundantly indicate which zone to update.</p></div></div><p>If you only have
one zone to update and don't want to use AjaxResponseRenderer, you can instead
return a value from your event handler method. The simplest case is just to
return the zone's own body:</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
private Request request;
@InjectComponent
@@ -98,7 +209,9 @@ private Zone myZone;
Object onActionFromSomeLink()
{
return myZone.getBody(); // AJAX request, return zone's own body
-}</plain-text-body><p>The possible return values are:</p><ul><li>An injected
Block or Component to render as the response. The response will be a JSON hash,
with a "content" key whose value is the rendered markup. This is the basis for
updates with the Zone component.</li><li>The zone's own body (using Zone's
getBody() method)</li><li>null (to redraw the current page)</li><li>A <a
class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/json/JSONObject.html">JSONObject</a>
or <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/json/JSONArray.html">JSONArray</a>,
which will be sent as the response.</li><li>A <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/StreamResponse.html">StreamResponse</a>,
which will be sent as the response.</li><li>A <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/Link.html">Link</a>,
wh
ich will send a redirect to the client.</li><li>A page name (as a String), or
a page class, or a page instance, which will send a redirect to the indicated
page.</li></ul><p>See <a href="page-navigation.html">Page Navigation</a> for
full descriptions of the above.</p><h3
id="AjaxandZones-GracefulDegradation">Graceful Degradation</h3><p>Users who do
not have JavaScript enabled may click EventLinks (or ActionLinks, or Forms)
that are configured to update a Zone. When that occurs, the request will still
be sent to the server, but Tapestry will handle it as a <em>traditional</em>
request.</p><p>This happens automatically when your event handler method has a
void return type.</p><p>However, to support graceful degradation when your
event handler method has a <em>non-void</em> return type, you should detect
non-Ajax requests and return a traditional response, typically null to redraw
the whole page. This is accomplished by injecting the <a class="external-link"
href="http://tapestry.apa
che.org/current/apidocs/org/apache/tapestry5/services/Request.html">Request</a>
object, and invoking the isXHR() method. This value will be true for Ajax
requests, and false for traditional request.</p><parameter
ac:name="language">java</parameter><plain-text-body>@Inject
+}</pre>
+</div></div><p>The possible return values are:</p><ul><li>An injected Block or
Component to render as the response. The response will be a JSON hash, with a
"content" key whose value is the rendered markup. This is the basis for updates
with the Zone component.</li><li>The zone's own body (using Zone's getBody()
method)</li><li>null (to redraw the current page)</li><li>A <a
class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/json/JSONObject.html">JSONObject</a>
or <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/json/JSONArray.html">JSONArray</a>,
which will be sent as the response.</li><li>A <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/StreamResponse.html">StreamResponse</a>,
which will be sent as the response.</li><li>A <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/Link.html">Link</a>,
which wil
l send a redirect to the client.</li><li>A page name (as a String), or a page
class, or a page instance, which will send a redirect to the indicated
page.</li></ul><p>See <a href="page-navigation.html">Page Navigation</a> for
full descriptions of the above.</p><h3
id="AjaxandZones-GracefulDegradation">Graceful Degradation</h3><p>Users who do
not have JavaScript enabled may click EventLinks (or ActionLinks, or Forms)
that are configured to update a Zone. When that occurs, the request will still
be sent to the server, but Tapestry will handle it as a <em>traditional</em>
request.</p><p>This happens automatically when your event handler method has a
void return type.</p><p>However, to support graceful degradation when your
event handler method has a <em>non-void</em> return type, you should detect
non-Ajax requests and return a traditional response, typically null to redraw
the whole page. This is accomplished by injecting the <a class="external-link"
href="http://tapestry.apache.org
/current/apidocs/org/apache/tapestry5/services/Request.html">Request</a>
object, and invoking the isXHR() method. This value will be true for Ajax
requests, and false for traditional request.</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
private Request request;
@InjectComponent
@@ -109,10 +222,11 @@ Object onActionFromSomeLink()
// return either the zone body (ajax) or whole page (non-ajax)
return request.isXHR() ? myZone.getBody() : null;
}
-</plain-text-body><h3 id="AjaxandZones-MultipleZoneUpdates">Multiple Zone
Updates</h3><p><plain-text-body>{float:right|background=#eee|padding=0 1em}
- *JumpStart Demo:*
- [AJAX Multiple Zone
Update|http://jumpstart.doublenegative.com.au/jumpstart/examples/ajax/multiplezoneupdate]
-{float}</plain-text-body>An event handler often needs to update multiple zones
on the client side. To accomplish this, use an <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/ajax/AjaxResponseRenderer.html">AjaxResponseRenderer</a>,
indicating the zones to update. You must know the client-side id for each zone
to update (the best way for this is to lock down the zone's id using the id
parameter of the Zone component).</p><p><em>AjaxResponseRenderer was introduced
in Tapestry 5.3. For Tapestry 5.2 and earlier, return a <a
class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/ajax/MultiZoneUpdate.html">MultiZoneUpdate</a>
object instead.</em></p><p>The renderer for each zone can be the zone itself,
a block, a component, a <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/Renderable.html">Renderable</a>
or a <a class="external-link" href="http://
tapestry.apache.org/current/apidocs/org/apache/tapestry5/runtime/RenderCommand.html">RenderCommand</a>
... or an object, such as String, that can be coerced to either of
these.</p><parameter ac:name="language">java</parameter><parameter
ac:name="title">For Tapestry 5.3 and
later</parameter><plain-text-body>@InjectComponent
+</pre>
+</div></div><h3 id="AjaxandZones-MultipleZoneUpdates">Multiple Zone
Updates</h3><p></p><div class="navmenu" style="float:right; background:#eee;
margin:3px; padding:0 1em">
+<p> <strong>JumpStart Demo:</strong><br clear="none">
+ <a class="external-link"
href="http://jumpstart.doublenegative.com.au/jumpstart/examples/ajax/multiplezoneupdate"
rel="nofollow">AJAX Multiple Zone Update</a></p></div>An event handler often
needs to update multiple zones on the client side. To accomplish this, use an
<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/ajax/AjaxResponseRenderer.html">AjaxResponseRenderer</a>,
indicating the zones to update. You must know the client-side id for each zone
to update (the best way for this is to lock down the zone's id using the id
parameter of the Zone component).<p><em>AjaxResponseRenderer was introduced in
Tapestry 5.3. For Tapestry 5.2 and earlier, return a <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/ajax/MultiZoneUpdate.html">MultiZoneUpdate</a>
object instead.</em></p><p>The renderer for each zone can be the zone itself,
a block, a component, a <a class="external-link" hr
ef="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/Renderable.html">Renderable</a>
or a <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/runtime/RenderCommand.html">RenderCommand</a>
... or an object, such as String, that can be coerced to either of
these.</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>For
Tapestry 5.3 and later</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default"
style="font-size:12px;">@InjectComponent
private Zone userInput;
@InjectComponent
@@ -126,13 +240,24 @@ void onActionFromRegister()
ajaxResponseRenderer.addRender("userInput",
userInput).addRender("helpPanel", helpPanel);
}
-</plain-text-body><p><span style="line-height: 1.4285715;">This example
assumes that there are two zones, "userInput" and "helpPanel", somewhere in the
rendered page, waiting to receive the updated content.</span></p><p><span
style="line-height: 1.4285715;"> </span></p><rich-text-body><p>In this
example, the Zone receives the update but does not provide any content. That's
OK, the other client-side elements (<code>userInput</code> and
<code>helpPanel</code>) will be updated, and the zone's content left
unchanged.</p></rich-text-body><p>This demonstrates why it is necessary for the
developer to specify a particular client-side id for Zone components; if they
were dynamically allocated ids, as is typical in most other elements, it would
be impossible for this code to know what client-side id was used for the
Zone.</p><h3 id="AjaxandZones-ZoneComponentIdvs.ZoneElementId">Zone Component
Id vs. Zone Element Id</h3><p>Like all Tapestry components, Zones have a
component id, specified
using the <code>t:id</code> attribute. If you do not assign a component id, a
unique id is assigned by Tapestry.</p><p>However, to coordinate things on the
client side, it is necessary for components that wish to update the zone know
the <em>client-side element id</em>. This is specified with the <code>id</code>
parameter of the Zone component. If the <code>id</code> parameter is not bound,
then a unique value (for the current page and render) is generated by Tapestry
and this value is difficult to predict. (The actual value will be available as
the <code>clientId</code> property of the Zone component
itself.)</p><p>Remember that the component id (<code>t:id</code>) is used to
<em>inject</em> the Zone component into the containing page or component. The
client-side id (<code>id</code>) is used on the client side to orchestrate
requests and updates. You will often seen the following
construct:</p><parameter
ac:name="language">xml</parameter><plain-text-body><t:zone t:id="myZone"
id="myzone"> ... </t:zone>
-</plain-text-body><h3
id="AjaxandZones-TheContainingZone(zone="^")">The Containing Zone
(zone="^")</h3><p><em><strong>Since 5.2</strong></em></p><p>If the Form or Link
is enclosed by the Zone itself, and you're using the <code>zone</code>
parameter instead of the <code>async</code> parameter, then
the <code>zone</code> parameter may be set to the special
value <strong><code>^</code></strong><code> (the carat)</code>. The zone
is found – on the client side – by searching up form the
form or link element for the first enclosing element that is a Zone. In this
way, the client-side coordination can occur without having to know what the
specific client-side id of the Zone is. Because of this, in some cases it is no
longer necessary to specify the Zone's <code>id</code> parameter.</p><h3
id="AjaxandZones-AnUpdatedivwithinaZonediv(Tapestry5.3andearlier)">An Update
div within a Zone div (Tapestry 5.3 and earlier)</h3><p><em><strong>De
precated</strong><strong>:</strong> This feature is removed starting with
Tapestry 5.4</em></p><p>In many situations, a Zone is a kind of "wrapper" or
"container" for dynamic content; one that provides a look and feel ... a bit of
wrapping markup to create a border. In that situation, the Zone <div> may
contain an update <div>.</p><p>An Update <div> is specifically a
<div> element marked with the CSS class "t-zone-update", <em>inside</em>
the Zone's <div>.</p><p>If an Update div exists within a Zone div, then
when Tapestry updates a zone only the update <div>'s content will be
changed, rather than the entire Zone <div>.</p><p>The show and update
functions (see Zone Functions, below) apply to the Zone <div>, not just
the update <div>.</p><h3
id="AjaxandZones-ZoneEffectFunctions(Tapestry5.3andearlier)">Zone Effect
Functions (Tapestry 5.3 and
earlier)</h3><p><strong><em>Deprecated:</em></strong> This feature refers to
client-side lo
gic only present in Tapestry 5.3 or earlier. For 5.4, there are client-side
events that are triggered before and after changes to the Zone; listeners on
those events can trigger whatever animations they like.</p><p>A Zone may be
initially visible or invisible. When a Zone is updated, it is made visible if
not currently so. This is accomplished via a function on the
Tapestry.ElementEffect client-side object. By default, the show() function is
used for this purpose. If you want Tapestry to call a different
Tapestry.ElementEffect function when updates occur, specify its name with the
zone's show parameter.</p><p>If a Zone is already visible, then a different
effect function is used to highlight the change. By default, the highlight()
function is called, which performs a yellow fade to highlight that the content
of the Zone has changed. Alternatively, you can specify a different effect
function with the Zone's update parameter:</p><div class="table-wrap"><table
class="confluenceTable"><
tbody><tr><th colspan="1" rowspan="1"
class="confluenceTh"><p>Tapestry.ElementEffect Function</p></th><th colspan="1"
rowspan="1" class="confluenceTh"><p>Result</p></th></tr><tr><td colspan="1"
rowspan="1" class="confluenceTd"><p>highlight()</p></td><td colspan="1"
rowspan="1" class="confluenceTd"><p>(the default) highlight changes to an
already-visible zone</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>show()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>make the zone visible if it isn't already
visible</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>slidedown()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>scroll the content down</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p>slideup()</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>slide the content back up
(opposite of slidedown)</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>fade()</p></td><td colspan=
"1" rowspan="1" class="confluenceTd"><p>fade the content out (opposite of
show)</p></td></tr></tbody></table></div><p>To have Tapestry update a zone
without the usual yellow highlight effect, just specify "show" for the update
parameter:</p><parameter
ac:name="language">xml</parameter><plain-text-body><t:zone t:id="myZone"
t:update="show"></plain-text-body><p>You may also define and use your own
JavaScript effect function (with lower-case names), like this:</p><parameter
ac:name="language">js</parameter><plain-text-body>Tapestry.ElementEffect.myeffectname
= function(element){ YourJavascriptCodeGoesHere; };
-</plain-text-body><h3 id="AjaxandZones-ZoneLimitations">Zone
Limitations</h3><p>Unlike many other situations, Tapestry relies on you to
specify useful and unique ids to Zone components, then reference those ids
inside EventLink (or ActionLink, or Form) components. Using Zone components
inside any kind of loop may cause additional problems, as Tapestry will
<em>uniqueify</em> the client id you specify (appending an index
number).</p><p>If you create a component that contains a zone, and you use that
component in a loop, you'll likely need to set the client-side id like
this:</p><p> </p><parameter
ac:name="language">xml</parameter><plain-text-body><t:zone t:id="myzone"
id="prop:componentResources.id"></plain-text-body><p> </p><p>See <a
class="external-link"
href="http://jumpstart.doublenegative.com.au/jumpstart7/examples/ajax/components1"
rel="nofollow">this JumpStart Example</a> for details.</p><p>The show and
update function names (Tapestry 5.3 and earlier only) are
converted to lower case; all the methods of Tapestry.ElementEffect should
have all lower-case names. Because client-side JavaScript is so fluid (new
methods may be added to existing objects), Tapestry makes no attempt to
validate the function names ... however, if the names are not valid, then the
default show and highlight methods will be used.</p><p>Zones may only be used
inside the <em>body</em> of a page, not the head<em>.</em></p><h3
id="AjaxandZones-MoreInformation">More Information</h3><p>For examples of
extending a Form with a Zone and updating multiple zones at once, see the <a
href="ajax-components-faq.html">Ajax Components FAQ</a>.</p><p>There are also a
number of Ajax-related examples at the  <a class="external-link"
href="http://jumpstart.doublenegative.com.au/jumpstart7/" rel="nofollow"><span
class="confluence-link">Tapestry JumpStart</span></a> site.</p><p><parameter
ac:name="">autocomplete</parameter></p><h2
id="AjaxandZones-AutocompleteMixin">Autocomple
te Mixin</h2><p><plain-text-body>{float:right|background=#eee|padding=0 1em}
- *JumpStart Demo:*
- [Autocomplete
Mixin|http://jumpstart.doublenegative.com.au/jumpstart/examples/ajax/autocompletemixin]
-{float}</plain-text-body>The <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/mixins/Autocomplete.html">Autocomplete</a>
mixin exists to allow a text field to query the server for completions for a
partially entered phrase. It is often used in situations where the field exists
to select a single value from a large set, too large to successfully download
to the client as a drop down list; for example, when the number of values to
select from is numbered in the thousands.</p><p>Autocomplete can be added to an
existing text field:</p><parameter
ac:name="language">java</parameter><plain-text-body> <t:textfield
t:id="accountName" t:mixins="autocomplete" size="100"/>
-</plain-text-body><p>The mixin can be configured in a number of ways, see the
<a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/mixins/Autocomplete.html">component
reference</a>.</p><p>When the user types into the field, the client-side
JavaScript will send a request to the server to get completions.</p><p>You must
write an event handler to provide these completions. The name of the event is
"providecompletions". The context is the partial input value, and the return
value will be converted into the selections for the user.</p><p>For
example:</p><parameter ac:name="language">java</parameter><plain-text-body>
List<String> onProvideCompletionsFromAccountName(String partial)
+</pre>
+</div></div><p><span style="line-height: 1.4285715;">This example assumes that
there are two zones, "userInput" and "helpPanel", somewhere in the rendered
page, waiting to receive the updated content.</span></p><p><span
style="line-height: 1.4285715;"> </span></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>In this example, the Zone receives
the update but does not provide any content. That's OK, the other client-side
elements (<code>userInput</code> and <code>helpPanel</code>) will be updated,
and the zone's content left unchanged.</p></div></div><p>This demonstrates why
it is necessary for the developer to specify a particular client-side id for
Zone components; if they were dynamically allocated ids, as is typical in most
other elements, it would be impossible for this code to know what client-sid
e id was used for the Zone.</p><h3
id="AjaxandZones-ZoneComponentIdvs.ZoneElementId">Zone Component Id vs. Zone
Element Id</h3><p>Like all Tapestry components, Zones have a component id,
specified using the <code>t:id</code> attribute. If you do not assign a
component id, a unique id is assigned by Tapestry.</p><p>However, to coordinate
things on the client side, it is necessary for components that wish to update
the zone know the <em>client-side element id</em>. This is specified with the
<code>id</code> parameter of the Zone component. If the <code>id</code>
parameter is not bound, then a unique value (for the current page and render)
is generated by Tapestry and this value is difficult to predict. (The actual
value will be available as the <code>clientId</code> property of the Zone
component itself.)</p><p>Remember that the component id (<code>t:id</code>) is
used to <em>inject</em> the Zone component into the containing page or
component. The client-side id (<code>id</code>) is
used on the client side to orchestrate requests and updates. You will often
seen the following construct:</p><div class="code panel pdl"
style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><t:zone t:id="myZone" id="myzone"> ...
</t:zone>
+</pre>
+</div></div><h3 id="AjaxandZones-TheContainingZone(zone="^")">The
Containing Zone (zone="^")</h3><p><em><strong>Since 5.2</strong></em></p><p>If
the Form or Link is enclosed by the Zone itself, and you're using
the <code>zone</code> parameter instead of the <code>async</code>
parameter, then the <code>zone</code> parameter may be set to the special
value <strong><code>^</code></strong><code> (the carat)</code>. The zone
is found – on the client side – by searching up form the
form or link element for the first enclosing element that is a Zone. In this
way, the client-side coordination can occur without having to know what the
specific client-side id of the Zone is. Because of this, in some cases it is no
longer necessary to specify the Zone's <code>id</code> parameter.</p><h3
id="AjaxandZones-AnUpdatedivwithinaZonediv(Tapestry5.3andearlier)">An Update
div within a Zone div (Tapestry 5.3 and earlier)</h3><p><em><strong>Deprecat
ed</strong><strong>:</strong> This feature is removed starting with Tapestry
5.4</em></p><p>In many situations, a Zone is a kind of "wrapper" or "container"
for dynamic content; one that provides a look and feel ... a bit of wrapping
markup to create a border. In that situation, the Zone <div> may contain
an update <div>.</p><p>An Update <div> is specifically a
<div> element marked with the CSS class "t-zone-update", <em>inside</em>
the Zone's <div>.</p><p>If an Update div exists within a Zone div, then
when Tapestry updates a zone only the update <div>'s content will be
changed, rather than the entire Zone <div>.</p><p>The show and update
functions (see Zone Functions, below) apply to the Zone <div>, not just
the update <div>.</p><h3
id="AjaxandZones-ZoneEffectFunctions(Tapestry5.3andearlier)">Zone Effect
Functions (Tapestry 5.3 and
earlier)</h3><p><strong><em>Deprecated:</em></strong> This feature refers to
client-side logic on
ly present in Tapestry 5.3 or earlier. For 5.4, there are client-side events
that are triggered before and after changes to the Zone; listeners on those
events can trigger whatever animations they like.</p><p>A Zone may be initially
visible or invisible. When a Zone is updated, it is made visible if not
currently so. This is accomplished via a function on the Tapestry.ElementEffect
client-side object. By default, the show() function is used for this purpose.
If you want Tapestry to call a different Tapestry.ElementEffect function when
updates occur, specify its name with the zone's show parameter.</p><p>If a Zone
is already visible, then a different effect function is used to highlight the
change. By default, the highlight() function is called, which performs a yellow
fade to highlight that the content of the Zone has changed. Alternatively, you
can specify a different effect function with the Zone's update
parameter:</p><div class="table-wrap"><table class="confluenceTable"><tbody>
<tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Tapestry.ElementEffect
Function</p></th><th colspan="1" rowspan="1"
class="confluenceTh"><p>Result</p></th></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>highlight()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>(the default) highlight changes to an already-visible
zone</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>show()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>make the zone visible if it isn't already
visible</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>slidedown()</p></td><td colspan="1" rowspan="1"
class="confluenceTd"><p>scroll the content down</p></td></tr><tr><td
colspan="1" rowspan="1" class="confluenceTd"><p>slideup()</p></td><td
colspan="1" rowspan="1" class="confluenceTd"><p>slide the content back up
(opposite of slidedown)</p></td></tr><tr><td colspan="1" rowspan="1"
class="confluenceTd"><p>fade()</p></td><td colspan="1" ro
wspan="1" class="confluenceTd"><p>fade the content out (opposite of
show)</p></td></tr></tbody></table></div><p>To have Tapestry update a zone
without the usual yellow highlight effect, just specify "show" for the update
parameter:</p><div class="code panel pdl" style="border-width: 1px;"><div
class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><t:zone t:id="myZone" t:update="show"></pre>
+</div></div><p>You may also define and use your own JavaScript effect function
(with lower-case names), like this:</p><div class="code panel pdl"
style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: js; gutter: false; theme: Default"
style="font-size:12px;">Tapestry.ElementEffect.myeffectname =
function(element){ YourJavascriptCodeGoesHere; };
+</pre>
+</div></div><h3 id="AjaxandZones-ZoneLimitations">Zone
Limitations</h3><p>Unlike many other situations, Tapestry relies on you to
specify useful and unique ids to Zone components, then reference those ids
inside EventLink (or ActionLink, or Form) components. Using Zone components
inside any kind of loop may cause additional problems, as Tapestry will
<em>uniqueify</em> the client id you specify (appending an index
number).</p><p>If you create a component that contains a zone, and you use that
component in a loop, you'll likely need to set the client-side id like
this:</p><p> </p><div class="code panel pdl" style="border-width:
1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><t:zone t:id="myzone"
id="prop:componentResources.id"></pre>
+</div></div><p> </p><p>See <a class="external-link"
href="http://jumpstart.doublenegative.com.au/jumpstart7/examples/ajax/components1"
rel="nofollow">this JumpStart Example</a> for details.</p><p>The show and
update function names (Tapestry 5.3 and earlier only) are converted to lower
case; all the methods of Tapestry.ElementEffect should have all lower-case
names. Because client-side JavaScript is so fluid (new methods may be added to
existing objects), Tapestry makes no attempt to validate the function names ...
however, if the names are not valid, then the default show and highlight
methods will be used.</p><p>Zones may only be used inside the <em>body</em> of
a page, not the head<em>.</em></p><h3 id="AjaxandZones-MoreInformation">More
Information</h3><p>For examples of extending a Form with a Zone and updating
multiple zones at once, see the <a href="ajax-components-faq.html">Ajax
Components FAQ</a>.</p><p>There are also a number of Ajax-related examples at
the  
;<a class="external-link"
href="http://jumpstart.doublenegative.com.au/jumpstart7/" rel="nofollow"><span
class="confluence-link">Tapestry JumpStart</span></a> site.</p><p><span
class="confluence-anchor-link" id="AjaxandZones-autocomplete"></span></p><h2
id="AjaxandZones-AutocompleteMixin">Autocomplete Mixin</h2><p></p><div
class="navmenu" style="float:right; background:#eee; margin:3px; padding:0 1em">
+<p> <strong>JumpStart Demo:</strong><br clear="none">
+ <a class="external-link"
href="http://jumpstart.doublenegative.com.au/jumpstart/examples/ajax/autocompletemixin"
rel="nofollow">Autocomplete Mixin</a></p></div>The <a class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/mixins/Autocomplete.html">Autocomplete</a>
mixin exists to allow a text field to query the server for completions for a
partially entered phrase. It is often used in situations where the field exists
to select a single value from a large set, too large to successfully download
to the client as a drop down list; for example, when the number of values to
select from is numbered in the thousands.<p>Autocomplete can be added to an
existing text field:</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;"> <t:textfield t:id="accountName"
t:mixins="autocomplete" size="100"/>
+</pre>
+</div></div><p>The mixin can be configured in a number of ways, see the <a
class="external-link"
href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/mixins/Autocomplete.html">component
reference</a>.</p><p>When the user types into the field, the client-side
JavaScript will send a request to the server to get completions.</p><p>You must
write an event handler to provide these completions. The name of the event is
"providecompletions". The context is the partial input value, and the return
value will be converted into the selections for the user.</p><p>For
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;"> List<String>
onProvideCompletionsFromAccountName(String partial)
{
List<Account> matches = accountDAO.findByPartialAccountName(partial);
@@ -145,7 +270,9 @@ void onActionFromRegister()
return result;
}
-</plain-text-body><p>This presumes that
<code>findByPartialAccountName()</code> will sort the values, otherwise you
will probably want to sort them. The Autocomplete mixin does <em>not</em> do
any sorting.</p><p>You can return an object array, a list, even a single
object. You may return objects instead of strings ... and
<code>toString()</code> will be used to convert them into client-side
strings.</p><p> </p><h2
id="AjaxandZones-Invokingserver-sideeventhandlermethodsfromJavaScript">Invoking
server-side event handler methods from JavaScript</h2><p>Tapestry 5.4.2
introduced an API which makes it easy for server-side events to be invoked from
JavaScript. On the server-side, you first need to annotate the event handler
methods you want to expose with
the <code>@PublishEvent</code> annotation. Then, in JavaScript, all
you need to do is to call the existing <code><a class="external-link"
href="http://tapestry.apache.org/current/coffeescript/ajax.html">t5/core/ajax</
a></code> function, but with slightly different
parameters.</p><p><code>The t5/core/ajax</code> function has two
parameters: <code>url</code> and <code>options</code>. Prior to
Tapestry 5.4.2, the first one was difficult to get when doing AJAX requests to
event handler methods. You needed to inject <code>ComponentResources in your
component class</code>,
call <code>componentResources.createEventLink()</code> for each event
handler method, then pass all this information back to the browser through one
of the <code>JavaScriptSupport</code> methods. For Tapestry 5.4.2 and
later, your JavaScript code only needs to know the event name (also called
<em>event type</em>) and optionally indicate a DOM element to be used as a
starting point for finding the event URL.</p><p>All event data is stored
in <code>data-componenent-events</code> attributes. For page classes, the
attribute is added to the <code><body></code> element. For
components, it's ad
ded to the first element rendered by the component. Given an HTML element, the
search is performed in the following order until information for the given
event is first found:</p><ol><li>The element itself</li><li>The element's
previous siblings, closest first (bottom-up)</li><li>The element's
parents</li><li>The page's <<code>body></code>
element</li></ol><p> </p><p>Here's one example:</p><parameter
ac:name="language">java</parameter><plain-text-body>public class
PublishEventDemoComponent
+</pre>
+</div></div><p>This presumes that <code>findByPartialAccountName()</code> will
sort the values, otherwise you will probably want to sort them. The
Autocomplete mixin does <em>not</em> do any sorting.</p><p>You can return an
object array, a list, even a single object. You may return objects instead of
strings ... and <code>toString()</code> will be used to convert them into
client-side strings.</p><p> </p><h2
id="AjaxandZones-Invokingserver-sideeventhandlermethodsfromJavaScript">Invoking
server-side event handler methods from JavaScript</h2><p>Tapestry 5.4.2
introduced an API which makes it easy for server-side events to be invoked from
JavaScript. On the server-side, you first need to annotate the event handler
methods you want to expose with
the <code>@PublishEvent</code> annotation. Then, in JavaScript, all
you need to do is to call the existing <code><a class="external-link"
href="http://tapestry.apache.org/current/coffeescript/ajax.html">t5/core/ajax</a></co
de> function, but with slightly different parameters.</p><p><code>The
t5/core/ajax</code> function has two parameters: <code>url</code>
and <code>options</code>. Prior to Tapestry 5.4.2, the first one was
difficult to get when doing AJAX requests to event handler methods. You needed
to inject <code>ComponentResources in your component class</code>,
call <code>componentResources.createEventLink()</code> for each event
handler method, then pass all this information back to the browser through one
of the <code>JavaScriptSupport</code> methods. For Tapestry 5.4.2 and
later, your JavaScript code only needs to know the event name (also called
<em>event type</em>) and optionally indicate a DOM element to be used as a
starting point for finding the event URL.</p><p>All event data is stored
in <code>data-componenent-events</code> attributes. For page classes, the
attribute is added to the <code><body></code> element. For
components, it's added to
the first element rendered by the component. Given an HTML element, the
search is performed in the following order until information for the given
event is first found:</p><ol><li>The element itself</li><li>The element's
previous siblings, closest first (bottom-up)</li><li>The element's
parents</li><li>The page's <<code>body></code>
element</li></ol><p> </p><p>Here's one 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;">public class PublishEventDemoComponent
{
@OnEvent("answer")
@PublishEvent
@@ -160,10 +287,14 @@ void onActionFromRegister()
}
}
-</plain-text-body><p>Notice that <code>answer()</code>
and <code>onAction()</code> are ordinary event handlers, with nothing
specific besides the <code>@PublishEvent</code> annotation.</p><parameter
ac:name="language">xml</parameter><plain-text-body><div id="component"
xmlns:t="http://tapestry.apache.org/schema/tapestry_5_0_0.xsd">
+</pre>
+</div></div><p>Notice that <code>answer()</code>
and <code>onAction()</code> are ordinary event handlers, with nothing
specific besides the <code>@PublishEvent</code> annotation.</p><div
class="code panel pdl" style="border-width: 1px;"><div class="codeContent
panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default"
style="font-size:12px;"><div id="component"
xmlns:t="http://tapestry.apache.org/schema/tapestry_5_0_0.xsd">
<p id="componentParagraph">I'm a component</p>
<p id="result">(no result yet)</p>
-</div></plain-text-body><p>The template also has nothing special. When
rendered, the component's events information is placed in the outer
<<code>div></code> (<code>id="component"). </code></p><p>We want to
update the text of <code><p id="result"></code> with the value of
the <code>origin</code> property of the returned JSON object when that
element itself is clicked, so here's our JavaScript code, supposing we want to
trigger the <code>answer</code> event:</p><parameter
ac:name="language">js</parameter><parameter
ac:name="linenumbers">true</parameter><plain-text-body>require(["t5/core/ajax",
"jquery"], function (ajax, $) {
+</div></pre>
+</div></div><p>The template also has nothing special. When rendered, the
component's events information is placed in the outer <<code>div></code>
(<code>id="component"). </code></p><p>We want to update the text
of <code><p id="result"></code> with the value of
the <code>origin</code> property of the returned JSON object when that
element itself is clicked, so here's our JavaScript code, supposing we want to
trigger the <code>answer</code> event:</p><div class="code panel pdl"
style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: js; gutter: true; theme: Default"
style="font-size:12px;">require(["t5/core/ajax", "jquery"], function (ajax, $) {
// Creating a callback to be invoked with <p id="result"> is clicked.
$('#result').click(function() {
ajax('answer', {
@@ -175,7 +306,8 @@ void onActionFromRegister()
}
});
});
-});</plain-text-body><p>If you're trying to invoke a page class event handler,
you can change line 5 above to <code>element: null</code>. You do need to
explicitly set the <code>element</code> property, otherwise
the <code>ajax</code> function will treat the first
parameter, <code>url</code>, as an URL and not as an event name.</p></div>
+});</pre>
+</div></div><p>If you're trying to invoke a page class event handler, you can
change line 5 above to <code>element: null</code>. You do need to
explicitly set the <code>element</code> property, otherwise
the <code>ajax</code> function will treat the first
parameter, <code>url</code>, as an URL and not as an event name.</p></div>
</div>
<div class="clearer"></div>