RIA with Flex - Part 1

Most of the present day Rich Internet Applications, especially on public arena are built with some or other Flash components. The embedded support of flash player for IE and other prominent browsers provided the edge of reach.

The reach can be understood with the well known day-2-day use application YouTube.

Evolution

Macromedia was a US graphics and Web development software company producing such products as Adobe Flash. The line of Macromedia products is now controlled by its former rival, Adobe Systems which acquired Macromedia on December 3, 2005.

Almost all prominent prgramming languages are gearing up to support this integration, ex- JavaFx. Among them Flex-promoted by Adobe can be considered as pioneer.

So, What is Flex?

Flex is a development and run-time environment that you use to create rich Internet applications that use Adobe® Flash® Player 9 to deliver more intuitive and interactive online experiences.

The flex applications are developed with MXML and Action Scripts.

MXML - Macromedia XML

Every Flex application contains at least one MXML file, known as the main application file. MXML is a markup language, an implementation of XML that was designed specifically for creating Flex applications, and you use it to declaratively define the structure of your application using tags.

Action Script

You add dynamic behavior to your applications using ActionScript 3.0, which is an implementation of ECMAScript and is similar to JavaScript. You can add ActionScript to Flex applications directly in the MXML file as script blocks or you can create separate files of ActionScript functions and import them into your MXML files.

Architecure

A Flex application is compiled into a SWF file, which runs in Flash Player. When the source code is compiled into a Flex application it is converted to ActionScript classes and is then merged into the SWF file along with graphics and other assets. At run time, the Flex application SWF file interacts with external libraries, services, and data sources as needed.

Standard Flex applications do not require server-side Flex services. Therefore, you compile them locally on your computer and typically deploy them to your users from an HTML page on a web server. As all browsers supports playing flash contents, you can code java script to play swf file on browser flash player.


Data Services

The major advantage of Flex addressed when it started supporting data services.

To provide data to your application, Adobe Flex includes components designed specifically for interacting with HTTP servers, web services, or remote object services (Java objects). These components are called remote procedure call (RPC) service components.

Unlike web applications built with Adobe ColdFusion, PHP, or similar server technologies, Flex applications cannot connect directly to a database. They interact with data using services. For example, you can insert an HTTP service in a Flex file to interact with a ColdFusion file that retrieves data from a MySQL database, converts it to XML, and then feeds it to your Flex application.

First Look on how you embed 'flash component - test.swf' on html page

<object width="425" height="373">
<param name="movie" value="test.swf"></param>
<param name="wmode" value="transparent"></param>
<embed src="test.swf"
type="application/x-shockwave-flash"
wmode="transparent"
width="425" height="373"></embed>
</object>