The state of Flex development

I’m currently working on a project which has a
Flex front-end talking to a ruby
on rails back-end. Someone recently asked me what I thought of Flex, and
my response is below. I’ve only been working with Flex for a couple of
months, so it’s very possible that there are solutions to the problems
listed below. If anyone knows a better way of doing it, please let me

Overall, I find the Flex (and ActionScript 3) world annoying and less
productive than either ruby or java.


Testing is weak in AS3.
FlexUnit doesn’t provide
dynamic test suites (see my post on Dynamically generating FlexUnit
Flex cannot create dynamic classes, so we cannot create dynamic mocks.
We would like to mock out flash classes (such as DisplayObject), but
instead, we are stuck with stubs and other work arounds. There is no way
to run a single test, so we have to compile the whole thing and run the
entire suite in the browser.


ActionScript 3 feels like a weird hybrid between java and javascript. It
allows you to specify the types in variable declarations and methods. If
you don’t specify a type, you get a warning, so the code winds up being
completely statically typed. They removed much of the flexibility of
ActionScript 2 (for example, no more eval), which is part of the reason
that mocking is hard. It feels like I’m back in java but without the
tool support (for example, cglib).


The main IDE is Adobe Flex
which is based on eclipse. Flex Builder provides some nice features like
syntax highlighting, autocomplete, and debugging. However, its compiler
is slow and we constantly have to wait to run our code. Refactoring is
limited to rename. There is no code formatter built in.


I prefer rake over ant, but FlexUnit provides a bunch of ant tasks
instead of command line tools. We will probably move towards a rake/ant
hybrid at some point. We were also seeing weird issues where test
failures would fail the build on macs, but not on linux. The tools all
seem immature.


Flex is new and sexy, and it is fun to see the output of what we make.
However, whenever I switch from ruby/textmate to flex/flex builder, I
groan a little. If you want to develop Flex without using an IDE, at least make sure you install the debug
version of flash in your browser. That way, when things blow up, you
will see stack traces. The regular version of flash will swallow all
errors without any indication of what went wrong.

Paul Gross

Paul Gross

I'm a lead software developer in Seattle working for Braintree Payments.

Read More