Flex: The new face of design and development

In terms of reach, functionality, interface richness, client ubiquity and the number of potential developers worldwide, Flex is one of the best ways to build a Rich Internet Application (RIA) today.

The term RIA was used first by Macromedia in a white paper produced in early 2002. It was a new term for something already perceived; applications that offered the functionality of a desktop application with a richer, more engaging user experience that also ran online.

In that white paper the company identified the drawbacks of the browser that we acknowledge as developers today and how those problems can be addressed with a Flash-based presentation tier.

Let's be honest here -- we've all been trying to make the web bend our way, and we're forcing functionality and design on something that was originally created as a text based communication tool.

Not only did Macromedia give something a name, in that same year they also presented a way to build RIAs with a set of new tools delivered to the developer community as part of the release of Flash MX in the shape of UI form components and ActionScript APIs that extended Flash in new ways that went well beyond "Skip Intro".

The next logical thing for Macromedia to do was to create a new developer-oriented method for creating Flash based applications to run in the Flash player, which in turn lead to the release in 2004 of Flex 1.0 - a presentation tier server and framework for enterprise level developers to create RIA front ends for their applications.

A Flex application is a combination of mark up language, framework, application server, and runtime:

• The markup language, MXML, is tag based and is derived from XML. It allows the developer to create a Flash front end to an application with a markup language that is not dissimilar to DHTML in terms of layout and styling attributes. MXML allows for both liquid and precise layout of design elements. Styling can be done with a CSS stylesheet. ActionScript is used to program client side application logic.
• The Flex presentation server compiles MXML into a Flash movie or SWF. The server also acts as a gateway for the Flash Player to communicate with Web Services and Remote Objects such as ColdFusion CFCs, Java and other objects that support Action Message Format (AMF). Flex applications are deployed as a WAR file to a J2EE server.
• Flex applications are compiled into Flash movies and are displayed in the browser via the Flash Player. They can also be run as standalone applications on the desktop via Macromedia Central.