How to find checkbox value ( checked/unchecked) in iteamreander of data grid ? - apache-flex

Question

I have 3 checkboxes for calculating amount purpose. I used Datagrid within datgrid used
<mx:DataGrid>
<mx:itemRenderer>
<mx:Component>
<mx:CheckBox id=mycheckbox change="calc()"/>
</mx:Component>
</mx:itemRenderer>
...
public function calc():void
{
statistic.dataProvider = mycheckbox.selectedItem;
}
but it's throws error like Call to possibly undfined method (calc)

Answer 1

You can't give the checkbox an id the way you have done and expect it to behave as a single component.
When you specify the checkbox as an item renderer for a column you are not talking about a single checkbox.
You will be dealing with as many check boxes as there are rows in the datagrid.
The following example shows you how to determine if the checkbox in a particular row is selected or not
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical"
creationComplete="init()">
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.controls.Alert;
private var ac:ArrayCollection=new ArrayCollection([
{name: "John", test: true},
{name: "Joe", test: false}]);
private function init() {
dg.dataProvider=ac;
}
public function check():void {
var obj:Object=dg.selectedItem;
Alert.show("Checkbox=" + obj.test);
}
]]>
</mx:Script>
<mx:DataGrid id="dg"
dataProvider="{ac}"
click="check()">
<mx:columns>
<mx:DataGridColumn dataField="name">
</mx:DataGridColumn>
<mx:DataGridColumn>
<mx:itemRenderer>
<mx:Component>
<mx:CheckBox label="Test"
selected="{data.test}"/>
</mx:Component>
</mx:itemRenderer>
</mx:DataGridColumn>
</mx:columns>
</mx:DataGrid>
</mx:Application>
Sometimes flex seems to have trouble updating the data provider for the datagrid when you have a nested itemrenderer. You can explicitly set the appropriate property of the dataprovider row when the change event occurs on the checkbox as below;
<mx:itemRenderer>
<mx:Component>
<mx:CheckBox label="Test" selected="{data.test}"
change="data.test=selected"/>
</mx:Component>
</mx:itemRenderer>

Answer 2

A checkbox does not have a "selectedItem" function or property...
mycheckbox.selected will return true or false based on whether or not sed checkbox is checked
Not really sure what you're trying to accomplish by setting a dataprovider to true or false, seems to me like you want to use a RadioButtonGroup

Answer 3

use outerDocument.functionname inside itemrenderer, and set the function as public. This is a limitation of Flex, Hierarchy mismanagement.