Introducing Flex

Flex is a programming language developed on adobe technology to enhance the users capability in building rich internet applications. This latest adobe technology possesses all flash features. Flex is embedded with two languages MXML and Action Script respectively. Among all known scripting languages Action Script is one of them that comes along with Flex SDK(software development kit). MXML is a tag based language while Action Script is a flash language and developers pro to oop's (object oriented programming) will face no problem with this flash language.

Server the compilation of flex source file  is adobe's Application server which is a J2EE application.
Flex coding is done with an XML based language known as MXML  and like Flash applications, Flex codes too are compiled into a file having SWF format called ShockWave Flash files. These SWF  files are executed with stand-alone Adobe's Flash Players, and can also be directly executed in browsers that have Adobe Flash Player Plug-in installed. 

For developing Flex applications, Adobe has launched Flex builder that works in Eclipse environment. Flex 3 builder is the latest and can be freely downloaded from Adobe's official website. But building Flex applications on Flex builder in eclipse environment is a cumbersome  job to perform, one reason is that using eclipse with flex builder plugin will make it very slow, also lot of time is been taken in compilation. To get rid of this problem there is another way to compile Flex application which works on Apache Ant technology. Apache's this technology is used to make a build.xml file that will be used later to call the flex compiler in deploying the flex application. You will get more to know after going through the tutorials presented below.

Flex languages

Flex coding involves two different languages MXML and ActionScript respectively.

MXML is an extended form of  XMLand is a tag based language, and therefore it is called an XML-based markup language. Program files coded with mxml language possess '.mxml'  extensions. MXML used along with ActionScript  provide tags to devise GUI (graphical user interface) component and is also used to get access to data on servers. MXML facilitates its users with its data binding services.  HTML and MXML both provide tags but the difference is that MXML consists of several new tags like TabNavigators and Accordions and many more that also enable users to get any web service connection. A MXML file is converted into a SWF file that runs on a Flash Player or on a browser which has Adobe Flash Player Plug-in installed in it.

ActionScript a flash language is an implementation of ECMAScript and is similar to OOP based JavaScript. In Adobe Flash Player this is the main programming tool. It consists of built-in objects  and functions, and allows its users to build their own objects and functions. With this strong tool one can extend its competency in creating RIAs. Its coding is done inside the tag <mx:Script/>. We create ActionScript files and call them inside the main MXML file with either 'source' attribute of <mx:Script> tag or with 'include' statement inside <mx:Script> tag by passing the relative path names of ActionScript files in these attributes. Each and  every ActionScript file should be saved with '.as' extension.