org.apache.tapestry5.corelib.components
Class Zone

java.lang.Object
  org.apache.tapestry5.corelib.components.Zone

All Implemented Interfaces:

ClientElement

@SupportsInformalParameters
public class Zone
extends Object
implements ClientElement

A Zone is portion of the output page designed for easy dynamic updating via Ajax or other client-side effects. A Zone renders out as a <div> element and may have content initially, or may only get its content as a result of client side activity.

Often, Zones are initially invisible, in which case the visible parameter may be set to false (it defaults to true).

When a user clicks an ActionLink whose zone parameter is set, the corresponding client-side Tapestry.Zone object is located. It will update the content of the Zone's <div> and then invoke either a show method (if the div is not visible) or an update method (if the div is visible). The show and update parameters are the names of functions attached to the Tapestry.ElementEffect object. Likewise, a Form component may also trigger an update of a client-side Zone.

Renders informal parameters, adding CSS class "t-zone" and possibly, "t-invisible".

You will often want to specify the id parameter of the Zone, in addition to it's Tapestry component id; this "locks down" the client-side id, so the same value is used even in later partial renders of the page (essential if the Zone is nested inside another Zone). When you specify the client-side id, it is used exactly as provided (meaning that you are responsible for ensuring that there will not be an id conflict even in the face of multiple partial renders of the page). Failure to provide an explicit id results in a new, and non-predictable, id being generated for each partial render, which will often result in client-side failures to locate the element to update when the Zone is triggered.

Constructor Summary

Zone()

Method Summary

Block	getBody() Returns the zone's body (the content enclosed by its start and end tags).
String	getClientId() Returns a unique id for the element.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Zone

public Zone()

Method Detail

getClientId

public String getClientId()

Description copied from interface: ClientElement

Returns a unique id for the element. This value will be unique for any given rendering of a page. This value is intended for use as the id attribute of the client-side element, and will be used with any DHTML/Ajax related JavaScript.

Specified by:

getClientId in interface ClientElement

getBody

public Block getBody()

Returns the zone's body (the content enclosed by its start and end tags). This is often used as part of an Ajax partial page render to update the client with a fresh render of the content inside the zone.

Returns:

the zone's body as a Block