Avoid Tracking"

From Documentation
(use @init instead of @load)
Line 1: Line 1:
 
{{ZKDevelopersReferencePageHeader}}
 
{{ZKDevelopersReferencePageHeader}}
 +
{{Deprecated | url=[http://books.zkoss.org/zk-mvvm-book/8.0/advanced/avoid_tracking.html zk-mvvm-book/8.0/data_binding/advanced/avoid_tracking]|}}
 +
  
  

Revision as of 07:25, 28 May 2015

Stop.png This article is out of date, please refer to zk-mvvm-book/8.0/data_binding/advanced/avoid_tracking for more up to date information.


When we create a property binding to a ViewModel's property, a tracker creates a corresponding tracking record to maintain this binding relationship. Thus when a binder reads properties from annotation @NotifyChange , it knows which attributes to reload upon the tracking records. This tracking task consumes time and memory and impacts application performance. If we have an object whose properties never change during whole application running, it's unnecessary to keep track of this immutable object's properties. We can apply @Immutable annotation on this immutable object to reduce the cost of tracking. If we bind a attribute to an immutable object's property, the tracker won't create a corresponding tracking record for it.

Immutable object

@Immutable
public class SysDefaultConfig{

}

Reference an immutable object

<label value="@init(vm.sysDefaultConfig.size)"/>



Version History

Last Update : 2015/05/28


Version Date Content
6.0.0 February 2012 The MVVM was introduced.




Last Update : 2015/05/28

Copyright © Potix Corporation. This article is licensed under GNU Free Documentation License.