Question

I’m working on Flash Builder with latest flex SDK.

I have a problem getting the value radioButton of the selceted radio button inside a form:

<mx:Form id="form_new_contribution"> 
 <mx:FormItem label="Contribution type" includeIn="project_contributions">
  <mx:RadioButtonGroup id="myG" enabled="true" />
  <mx:RadioButton id="subtitle" label="subtitle" groupName="{myG}" value="subtitle"/>
  <mx:RadioButton id="note" label="notes / chapters" groupName="{myG}" value="note"/>
 </mx:FormItem>
</mx:Form>

the function is:

protected function button_add_new_clickHandler(event:MouseEvent):void{
 Alert.show(myG.selectedValue.toString());
}

I tried also:

Alert.show(myG.selection.toString());

bothe codes show error:

TypeError: Error #1009: Cannot access a property or method of a null object reference.

and if It only works if I put :

Alert.show(myG.toString());

it alerts : Object RadioButtonGroup

thanx for any hints, and sorry for the long message 🙂

Answer 1

The only thing I see wrong here is that the groupName property of RadioButton is a string, not a curly-braced reference to a RadioButtonGroup.

You should render it as:

 <mx:RadioButton id="subtitle" label="subtitle" groupName="myG" value="subtitle"/>

not

 <mx:RadioButton id="subtitle" label="subtitle" groupName="{myG}" value="subtitle"/>

Or you can also use the group property with an RBG reference:

 <mx:RadioButton id="subtitle" label="subtitle" group="{myG}" value="subtitle"/>