Devin Columbus aka dColumbus | 9 March 2008
There seems to be some confusion as to why anyone
would bother using Flex. I can understand this to a
degree since I felt the exact same way when I first
heard about Flex. But logically, there must be a reason
why Adobe decided to continue it as one of their
products; and that is exactly what I plan to explain
In a nutshell, Flex was designed in order to give Flash
Developers an edge when developing Rich Internet
Applications (RIAs). Although RIAs can be built from within
Flash, there are various limitations, especially when it
come to a developers time. Iím not going to get into the
specifics, but as you become familiar with Flex, youíll begin to
understand why this is.
A Flex application at itís very basic level is a Flash .swf
file embedded in a generated HTML file. Since Flex outputs
itís data as a .swf, this allows you to utilize everything
that Flash Player is famous for; dynamic animations, sound
and video handling, and of course, the Flash Drawing API.
code in order to detect whether the user has the Flash
Player installed, or whether they need to update to the
One of the major reasons why Flex is becoming more and
more popular is because it utilizes ActionScript 3.0. In
fact, developers weíre creating AS 3.0 applications in Flex
even before AS 3.0 was released for Flash Developers. But,
since Flash CS3 was released, AS 3.0 has become the new
standard, and for me at least, is why developing in Flex has
become even more exciting.
One important thing to note, is that the Flex environment
does not use a Timeline. This does not mean that it is
limited. Rather, Flex has been developed more for
programmers and less for designers. It ends up meeting
somewhere in the middle, which is exactly where I found
myself as a Designer/Programmer, whatever. Again, this will
become apparent as you begin actually developing in Flex.
You design a Flex Application by selecting pre-defined
visual components (i.e. Button, ComboBox, ListBox, DataGrid,
etc) that youíre most likely familiar with from Flash. If
youíve never used components before, theyíre wonderful.
Although some will tell you that you can create far smaller
(in size) components by developing them on your own, and
while that may actually be true, the pre-defined components
work well and are highly customizable Ė especially the
latest set released with Adobe Creative Suite 3:
[ an example of a few controls arranged
in Flex Builder 3 ]
You then arrange your components on the stage in a
orderly, easy to use, manageable user interface. There are
various Containers that allow you to align your components
however youíd like. As an example of one of these
containers, there is one named the VBox. This Container
tells everything that lives within it to align vertically to
one another Ė extremely usefully when developing Forms.
Youíll then use be able to use styles and skins that will
customize the entire look and feel of your application. CSS
Formatting and the complete customization of the visual
components (as I mentioned above) will make your Flex
Application stand out above the rest.
Now that you have your visuals in place and you like the
way your application looks, you can start to utilize
ActionScript 3.0. A/ssign event handlers and create or import
ActionScript functions or classes to make your Flex
Application live up to itís full potential. This will allow
you to react to what the user does and to events that are
generated by Flex itself. Also, and this is a HUGE also,
youíre able to connect to ColdFusion and other Flex
Data/Communication Services. Remember this one thing when
youíre contemplating whether or not Flex is right for you:
Flex and ColdFusion are meant for each other.
Now itís time to publish your application and present it
to your client or the world.
Honestly, there is so much
more that could have been elaborated on in this article, but
thatís what the later tutorials are there for. This was
meant as an introduction or sorts to Flex in a Flash world.
If you havenít given it a shot, why not test it out for
yourself. Until more tutorials are released here on
Kirupa.com, please visit the following links in order to
satisfy your curiosity.
Download the latest Flex Builder 3:
The Adobe Flex Developers Center:
The Official Adobe Flex Overview:
If you have any questions, feel free to post them on the