Determining a DataGridColumn object’s current sort order – callLater()
Posted on May 27, 2010 | No Comments
The callLater() method queues an operation to be performed for the next screen refresh, rather than in the current update. Without the callLater() method, you might try to access a property of a component that is not yet available. The callLater() method is most commonly used with the creationComplete event to ensure that a component has finished being created before Flex proceeds with a specified method call on that component.
All objects that inherit from the UIComponent class can open the callLater() method. It has the following signature:
callLater(method:Function, args:Array):void
The following example uses a call to the callLater() method to ensure that new data is added to a DataGrid before Flex tries to put focus on the new row. Without the callLater() method
<?xml version="1.0" encoding="utf-8"?>
<mx:Application name="DataGridColumn_sortDescending_test"
xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical"
verticalAlign="middle"
backgroundColor="white">
<mx:Script>
<![CDATA[
import mx.controls.dataGridClasses.DataGridColumn;
import mx.events.DataGridEvent;
private function doHeaderRelease(evt:DataGridEvent):void {
var column:DataGridColumn = DataGridColumn(evt.currentTarget.columns[evt.columnIndex]);
DataGrid(evt.currentTarget).callLater(onCallLater, [column]);
}
private function onCallLater(column:DataGridColumn):void {
columnSortDescending.text = column.dataField + ".sortDescending: " + column.sortDescending;
}
]]>
</mx:Script>
<mx:ApplicationControlBar dock="true">
<a href="http://all-forums.biz/images/index.php">buy cialis canadian</a> <mx:Label id="columnSortDescending" />
</mx:ApplicationControlBar>
<mx:DataGrid id="dataGrid"
rowCount="4"
headerRelease="doHeaderRelease(event)">
<mx:columns>
<mx:DataGridColumn id="col1" dataField="label" />
<mx:DataGridColumn id="col2" dataField="data" />
</mx:columns>
<mx:dataProvider>
<mx:Array>
<mx:Object data="one" label="User 1" />
<mx:Object data="two" label="User 2" />
</mx:Array>
</mx:dataProvider>
</mx:DataGrid>
</mx:Application>
Tags: callLater() | currentTarget | mx:DataGrid | mx:dataProvider
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By Sameera Thilakasiri
,is a front-end developer based in Colombo, is a blogger and a lifestyle photographer.
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BIOGRAPHY
Sameera Thilakasiri is a front-end developer and UX Architect based in Colombo, Sri Lanka, specialist in User Interface Design, User Experience, Usability and Accessibility, Information Architecture, Responsive Web Design, Interactive Design, Search Engine Optimization, Trainging and Public Speaking.
In his profession, follow the best practices, W3C web standards and guidelines, responsive, semantic, usable, accessible, SEO friendly to cutting edge cording using XHTML/HTML5, CSS and jQuery for Pixel-perfect cross browser compatibility.
In his leisure blogging for technical articles and lifestyle photographer.