Flex is a very powerful and versatile technology for creating web application front-ends. But what every good web application needs is a robust data source, be it XML, or a database. Flex is very adaptable in terms of connecting to data sources, and that is the main focus of this book. In Foundation Flex for Developers, Sas and Koen assume that you've got the basics of Flex down already, and explores in detail how to create professional data-centric Flex 2 and Flex 3 applications. In the first half of the book, she starts off with a brief exploration of Flex and ActionScript 3.0, before looking at application essentials in detail—creating custom components, user and web browser interactions, binding, formatting, and validating data, debugging, and more. In the second half of the book, the focus is on connecting Flex to data sources, and covers XML, LiveCycle Data Services, PHP, ASP.NET, and ColdFusion in detail, via a series of step-by-step case studies.