I have to give the Adobe Flash team big props on the new Spark framework’s focus on separated logic. Not only does it enhance my productivity and sanity, but it has opened wide the door for and encouraged the Flex community to create vast reusable code in ways that Flex 3 had problems encouraging developers to do.
For instance, the Spark separated layout structure with a DI slant has already saved time and encouraged so many layout concepts that are no longer component based solutions (example). The community is now able to focus on solving small solutions and then combining them into greater solution for a given project!

I expect to see more focused classes coming soon.

UPDATE (June 10, ’10):
The focus on solution driven instead of component has allowed Adobe to have features like Layout Mirroring (link). This further demonstrates the power of developing a DI driven framework. I encourage more of us to architect this way. OH MAN, did I really suggest us to architect like Adobe?!

Situation: I was working with the Spark (Flex4) TextArea component. I wanted the background to no longer be visible or just simply alpha set to zero. I expected I could set a stylesheet property backgroundAlpha to zero. However, that didn’t work and there wasn’t even a property on the component called that. I dug in the source to find it and realized it is really contentBackgroundAlpha. Why? I see borderAlpha and expect to follow the same convention! I do not see contentBorderAlpha.

Why break a convention?
Why use contentBackgroundAlpha when borderAlpha is present and there is not already a backgroundAlpha?!