Packagespark.components
Classpublic class RadioButtonGroup
InheritanceRadioButtonGroup Inheritance flash.events.EventDispatcher
Implements IMXMLObject

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

The RadioButtonGroup component defines a group of RadioButton components that act as a single mutually exclusive component; therefore, a user can select only one RadioButton component at a time. The id property is required when you use the <s:RadioButtonGroup> tag to define the group name. Any <s:RadioButton> component added to this group will have this group name.

Notice that the RadioButtonGroup component is a subclass of EventDispatcher, not UIComponent, and implements the IMXMLObject interface. All other Flex visual components implement the IVisualElement interface. The RadioButtonGroup component declaration must be contained within the <Declarations> tag since it is not assignable to IVisualElement.

To use this component in a list-based component, such as a List or DataGrid, create an item renderer. For information about creating an item renderer, see Custom Spark item renderers.

MXML SyntaxexpandedHide MXML Syntax

The <s:RadioButtonGroup> tag inherits all of the tag attributes of its superclass, and adds the following tag attributes:

  <s:RadioButtonGroup
    Properties
    enabled="true"
    selectedValue="null"
    selection="null"
     Events
    change="No default"
    itemClick="No default"
    valueCommit="No default"
  />
  

View the examples

See also

spark.components.RadioButton


Public Properties
 PropertyDefined By
  enabled : Boolean
Determines whether selection is allowed.
RadioButtonGroup
  numRadioButtons : int
[read-only] The number of RadioButtons that belong to this RadioButtonGroup.
RadioButtonGroup
  selectedIndex : int
The index of the selected RadioButton component in the group.
RadioButtonGroup
  selectedValue : Object
The value property of the selected RadioButton component in the group, if it has been set, otherwise, the label property of the selected RadioButton.
RadioButtonGroup
  selection : RadioButton
Contains a reference to the currently selected RadioButton component in the group.
RadioButtonGroup
Public Methods
 MethodDefined By
  
Constructor.
RadioButtonGroup
  
Returns the RadioButton component at the specified index.
RadioButtonGroup
  
initialized(document:Object, id:String):void
Implementation of the IMXMLObject.initialized() method to support deferred instantiation.
RadioButtonGroup
Events
 Event Summary Defined By
  Dispatched when the value of the selected RadioButton component in this group changes.RadioButtonGroup
  Dispatched when a user selects a RadioButton component in the group.RadioButtonGroup
  Dispatched when values are changed programmatically or by user interaction.RadioButtonGroup
Property Detail
enabledproperty
enabled:Boolean

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

Determines whether selection is allowed. Note that the value returned only reflects the value that was explicitly set on the RadioButtonGroup and does not reflect any values explicitly set on the individual RadioButtons.

The default value is true.


Implementation
    public function get enabled():Boolean
    public function set enabled(value:Boolean):void
numRadioButtonsproperty 
numRadioButtons:int  [read-only]

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

The number of RadioButtons that belong to this RadioButtonGroup.

The default value is "0".

This property can be used as the source for data binding.


Implementation
    public function get numRadioButtons():int
selectedIndexproperty 
selectedIndex:int

Language Version : ActionScript 3.0
Product Version : Flex 4.10
Runtime Versions : Flash Player 11.1, AIR 3.4

The index of the selected RadioButton component in the group. If a RadioButton is not selected, this property is -1.

The default value is -1.

This property can be used as the source for data binding.


Implementation
    public function get selectedIndex():int
    public function set selectedIndex(value:int):void
selectedValueproperty 
selectedValue:Object

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

The value property of the selected RadioButton component in the group, if it has been set, otherwise, the label property of the selected RadioButton. If no RadioButton is selected, this property is null.

If you set selectedValue, Flex selects the first RadioButton component whose value or label property matches this value.

The default value is null.

This property can be used as the source for data binding.


Implementation
    public function get selectedValue():Object
    public function set selectedValue(value:Object):void
selectionproperty 
selection:RadioButton

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

Contains a reference to the currently selected RadioButton component in the group. You can access this property in ActionScript only; it is not settable in MXML. Setting this property to null deselects the currently selected RadioButton component. A change event is not dispatched.

The default value is null.

This property can be used as the source for data binding.


Implementation
    public function get selection():RadioButton
    public function set selection(value:RadioButton):void
Constructor Detail
RadioButtonGroup()Constructor
public function RadioButtonGroup(document:IFlexDisplayObject = null)

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

Constructor.

Parameters
document:IFlexDisplayObject (default = null) — In simple cases where a class extends EventDispatcher, the document parameter should not be used.

See also

flash.events.EventDispatcher
Method Detail
getRadioButtonAt()method
public function getRadioButtonAt(index:int):RadioButton

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

Returns the RadioButton component at the specified index.

Parameters

index:int — The 0-based index of the RadioButton in the RadioButtonGroup.

Returns
RadioButton — The specified RadioButton component if index is between 0 and numRadioButtons - 1. Returns null if the index is invalid.

See also

numRadioButtons
initialized()method 
public function initialized(document:Object, id:String):void

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

Implementation of the IMXMLObject.initialized() method to support deferred instantiation.

Parameters

document:Object — The MXML document that created this object.
 
id:String — The identifier used by document to refer to this object. If the object is a deep property on document, id is null.

See also

Event Detail
change Event
Event Object Type: flash.events.Event
Event.type property = flash.events.Event.CHANGE

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

Dispatched when the value of the selected RadioButton component in this group changes.

itemClick Event  
Event Object Type: mx.events.ItemClickEvent
ItemClickEvent.type property = mx.events.ItemClickEvent.ITEM_CLICK

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

Dispatched when a user selects a RadioButton component in the group. You can also set a handler for individual RadioButton components. This event is dispatched only when the user interacts with the radio buttons by using the mouse.

The ItemClickEvent.ITEM_CLICK constant defines the value of the type property of the event object for an itemClick event.

The properties of the event object have the following values:

PropertyValue
bubblesfalse
cancelablefalse
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
indexThe index of the navigation item that was clicked.
itemThe item in the data provider of the navigation item that was clicked.
labelThe label of the navigation item that was clicked.
relatedObjectThe child object that generated the event.
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.
valueCommit Event  
Event Object Type: mx.events.FlexEvent
FlexEvent.type property = mx.events.FlexEvent.VALUE_COMMIT

Language Version : ActionScript 3.0
Product Version : Flex 4
Runtime Versions : Flash Player 10, AIR 1.5

Dispatched when values are changed programmatically or by user interaction.

Because a programmatic change triggers this event, make sure that any valueCommit event handler does not change a value that causes another valueCommit event. For example, do not change theselectedValue property or selection property in a valueCommit event handler.

The FlexEvent.VALUE_COMMIT constant defines the value of the type property of the event object for a valueCommit event.

The properties of the event object have the following values:

PropertyValue
bubblesfalse
cancelablefalse
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.
Examples
RadioButtonGroupExample.mxml
<?xml version="1.0" encoding="utf-8"?>
<!--

  Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

-->
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
               xmlns:s="library://ns.adobe.com/flex/spark" 
               xmlns:mx="library://ns.adobe.com/flex/mx">
    <fx:Script>
        <![CDATA[   
            
            import mx.controls.Alert;
            import mx.events.ItemClickEvent;
            
            private function handlePayment(event:ItemClickEvent):void {
                if (event.currentTarget.selectedValue == "check") {
                    Alert.show("You opted to pay by check."); 
                } else if (event.currentTarget.selectedValue == "credit") {
                    Alert.show("You opted to pay by credit card.");
                }
            }
        ]]>
    </fx:Script>
    
    <fx:Declarations>
        <s:RadioButtonGroup id="paymentType" itemClick="handlePayment(event);"/>
    </fx:Declarations>
    <s:VGroup paddingLeft="10" paddingTop="10">
        <s:RadioButton groupName="paymentType" 
                       id="payCheck" 
                       value="check" 
                       label="Pay by check" 
                       width="150"/>
        <s:RadioButton groupName="paymentType" 
                       id="payCredit" 
                       value="credit" 
                       label="Pay by credit card" 
                       width="150"/>
    </s:VGroup>
</s:Application>