How to pass a value from 1 mxml componet to the another mxml componet

Question

I have created 3 mxml components. I am using 1st component as
a container component for other 2 components mean[ inside 1st
component i have placed 2 other components]. now i want to pass
selectedvalue from 1 component to another component.
say 1st component is
MyFirstComponent.mxml
2nd component is
MySecComponent.mxml
3rd component is
MyThirdComponent.mxml
now i have place 2nd & 3rd component in 1st component.
whenever i select an item from dropdown in 2nd component i want to
set/pass that selectedvalue to 3rd component public variable. how
can i achieve this.
MySecondComponent.mxml
[code]
<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="
http://www.adobe.com/2006/mxml"
xmlns:salesforce="
http://www.salesforce.com/"
creationComplete="login()">
<mx:ComboBox x="102" y="26" id="ddlDepartmentName"
cornerRadius="2" height="20"
fontWeight="bold" width="148"/>
</mx:Canvas>
[/code]
MyThirdComponent.mxml
[code]
<?xml version="1.0" encoding="utf-8"?>
<mx:HBox xmlns:mx="
http://www.adobe.com/2006/mxml"
xmlns:salesforce="
http://www.salesforce.com/"
creationComplete="login();">
<mx:Script>
<![CDATA[
import SubComponents.Department.DepartmentSummary;
public var departmentID:String = 10;
]]>
</mx:Script>
</mx:HBox>
[/code]
right now i am using hardcoded departmentID in 3rd component,
i want to remove the hardcoded value and i want to set the value
from 2nd components' on selectionChange.
When i select department Name from the comboBox which is
created in 2nd component i want to get the value in 3rd component.
how can i achive this..
want to set the departmentID in 3rd component to the
ddlDepartmentName.selectedValue in 2nd component. when i change the
selected value in 2nd component i want to display the department
information in 3rd component after setting the departmentID
Waiting for your valuable answer.

Answer 1

This code seems to work:
------------------ MyThirdComponent.mxml -------------------
<?xml version="1.0" encoding="utf-8"?>
<mx:HBox xmlns:mx="
http://www.adobe.com/2006/mxml"
xmlns:salesforce="
http://www.salesforce.com/">
<mx:Script>
<![CDATA[
[Bindable]
public var departmentID:String = new String();
]]>
</mx:Script>
<mx:Text text="{departmentID}"/>
</mx:HBox>
------------------------- MySecondComponent.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:mx="
http://www.adobe.com/2006/mxml"
xmlns:salesforce="
http://www.salesforce.com/">
<mx:Script>
<![CDATA[
public function changeHandler():void{
this.parentApplication.my3rd.departmentID =
ddlDepartmentName.selectedLabel;
]]>
</mx:Script>
<mx:ComboBox x="102" y="26" id="ddlDepartmentName"
cornerRadius="2" height="20"
fontWeight="bold" width="148" change="changeHandler()">
<mx:ArrayCollection>
<mx:String>Bananas</mx:String>
<mx:String>Apples</mx:String>
<mx:String>Oranges</mx:String>
</mx:ArrayCollection>
</mx:ComboBox>
</mx:Canvas>
----------------------- Test.mxml
<?xml version="1.0"?>
<mx:Application xmlns:mx="
http://www.adobe.com/2006/mxml"
xmlns:comp="components.*" creationComplete="init()">
<mx:Script>
<![CDATA[
public function init():void{
my3rd.departmentID = my2nd.ddlDepartmentName.selectedLabel;
]]>
</mx:Script>
<comp:MyThirdComponent id="my3rd"/>
<comp:MySecondComponent id="my2nd"/>
</mx:Application>