User Guide

40 Creating Custom Events

Using the Event metadata tag

You use the [Event] metadata tag to define events dispatched by a component so that the

Flex compiler can recognize them as MXML tag attributes in an MXML file. You add the

[Event] metadata tag in one of the following locations:

ActionScript components Above the class definition, but within the package definition, so

that the events are bound to the class and not a particular member of the class.

MXML components In the <mx:Metadata> tag of an MXML file.

The Event metadata keyword has the following syntax:

[Event(name=”eventName”, type=”package.eventType”)]

The eventName argument specifies the name, including the package, of the event. The

eventType argument specifies the class that defines the event.

The following example identifies the

enableChange event as an event that an ActionScript

component can dispatch:

[Event(name="enableChange", type="myEvents.EnableChangeEvent")]

public class MyComponent extends TextArea

{

...

}

The following example shows the [Event] metadata tag within the <mx:Metadata> tag of an

MXML file:

<?xml version="1.0"?>

<mx:Button xmlns:mx="http://www.adobe.com/2006/mxml"

click="dispatchEvent(new EnableChangeEvent('enableChanged'));">

<mx:Script>

<![CDATA[

import myEvents.EnableChangeEvent;

]]>

</mx:Script>

<mx:Metadata>

[Event(name="enableChanged", type="myEvents.EnableChangeEvent")]

</mx:Metadata>

</mx:Button>