The Essential Guide to Flex 2 with ActionScript 3.0 / Edition 1

Flex Demystified.

Flex 2 with ActionScript 3.0 By Charles E. Brown Publisher: Friends of Ed Copyright 2007 IBSN:-13 (pbk) 978-1-59059-733-0 Reviewer: Linda Weller The author explains Flex in a very interesting instructive way. It explains the meaning of Flex and ActionScript 3.0 in the new Flash landscape. One of the great things about this book is that the author looks at all aspects of Flex from high/low levels and from a designer/developer perspective. It was great to discover if you can use XML or Dreamweaver you can use Flex. Flex will bring the web to a new level. Flex was introduced in 2004 as a solution to having to learn about Flash¿s scenes and timelines. Flex is a more traditional programming environment. It combines .mxml and ActionScript 3.0. The author urges everyone to ¿stop thinking page to page website and think smooth flowing desktop applications. Flex Builder 2 is built around Eclipse. The GUI uses XHTML and OOP. You use ActionScript 3.0 to extend the power of .mxml. When you add ActionScript 3.0 to Flex you can add dynamic interaction between your components. When you compile an application to a .swf it transforms the .mxml code to ActionScript 3.0 The goal of Flex is rapid development. You use ActionScript to connect the components together and .mxml to tell Flex how to assemble pre-build containers. When beginning to do work in Flex he suggests that you start in design view and then move to code view to fine tune things. One of the benefits of using Flex over HTML is that it has adjustability to many sizes. You could take the same application you used on the web and scale it down for mobile for example. The downside of .mxml is that it can¿t loop or make decisions so you need ActionScript 3.0 for this. In AS 3.0 we now have Sprite which is essentially a Movie Clip without a timeline. Charles Brown explains that between the CDATA tags is where your ActionScript code is placed. To create a new .mxml document you must first create a new Flex project. The main purpose of Flex is to present data and therefore it is called a presentation server. Flex applications are build by creating containers within containers the application tags being the outermost containers. He covers the Navigation Containers: View Stack, Accordian and Tab Navigator. These are the ingredients that give Flex its rapid development reputation. New class files for the easy access of XML have been implemented called E4X. The section about displaying data with a data grid presents another rapid development feature. He discusses states which give you the timeline functionality without the timeline. He makes the distinction that Flex is not an animation program so, it will not be replacing Flash. He wraps up the last part of the book by launching into a two part case study of building a shopping cart utilizing all the concepts he has introduced earlier in the book.