var firstDay:Date=new Date(yearNumber, monthNumber);
var lastDay:Date=new Date(yearNumber, monthNumber +1, 0);

Flex example to apply a blink effect to a row in a list in an update event.

Click with the right button to obtain source code.

In a flex component which expose a calculated property is necessary to implement a system to listening internal changes and dispatch them to the main application. It could be achieved with accessors methods bindabled with an internal event when it must recalculate the property.

An example:

<?xml version="1.0" encoding="utf-8"?>
<mx:HBox xmlns:mx="http://www.adobe.com/2006/mxml" width="100%" height="100%">
	<mx:Script>
		<![CDATA[
			import mx.collections.ArrayCollection;
			[Bindable]
			private var items1:ArrayCollection=new ArrayCollection([
				2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010
			]);
			[Bindable]
			private var items2:ArrayCollection=new ArrayCollection([
				"Enero","Febrero","Marzo","Abril","Mayo","Junio","Julio","Agosto","Septiembre","Octubre","Noviembre","Diciembre"
			]);

			private var _myDate:Date;
			[Bindable ("change")]
			public function set myDate(value:Date):void {
				_myDate=value;
				year.selectedItem=int(value.getFullYear());
				month.selectedIndex=value.getMonth();
			}
			public function get myDate():Date {
				_myDate.setFullYear(year.selectedItem, month.selectedIndex+1, 0);
				return _myDate;
			}
		]]>
	</mx:Script>

	<mx:ComboBox id="year" dataProvider="{items1}" change="{dispatchEvent(new Event('change'))}"/>
	<mx:ComboBox id="month" dataProvider="{items2}" change="{dispatchEvent(new Event('change'))}"/>
</mx:HBox>

Bindable only in set method.

[RPC Fault faultString="Unable to access UserTransaction in DataService." faultCode="Server.Processing" faultDetail="null"]
at mx.data::ConcreteDataService/http://www.adobe.com/2006/flex/mx/internal::dispatchFaultEvent()[C:\depot\DataServices\branches\lcds26_hotfixes\frameworks\projects\data\src\mx\data\ConcreteDataService.as:2556]
at mx.data::CommitResponder/fault()[C:\depot\DataServices\branches\lcds26_hotfixes\frameworks\projects\data\src\mx\data\CommitResponder.as:176]
at mx.rpc::AsyncRequest/fault()[E:\dev\3.1.0\frameworks\projects\rpc\src\mx\rpc\AsyncRequest.as:103]
at NetConnectionMessageResponder/statusHandler()[E:\dev\3.1.0\frameworks\projects\rpc\src\mx\messaging\channels\NetConnectionChannel.as:545]
at mx.messaging::MessageResponder/status()[E:\dev\3.1.0\frameworks\projects\rpc\src\mx\messaging\MessageResponder.as:222]

SOLUTION: Install JTOM in Tomcat, include jtom libraries and add in the file “context.xml” of the server this code:

<Transaction factory="org.objectweb.jotm.UserTransactionFactory" jotm.timeout="60"/>

org.springframework.beans.factory.BeanCreationException: Error creating bean with name ’sessionFactory’ defined in ServletContext resource [/WEB-INF/applicationContext-hibernate.xml]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: java.lang.NoSuchMethodException: org.hibernate.validator.ClassValidator.(java.lang.Class, java.util.ResourceBundle, org.hibernate.validator.MessageInterpolator, java.util.Map, org.hibernate.annotations.common.reflection.ReflectionManager)

SOLUTION: include “hibernate-validator.jar”