Quickly creating re-usable components based on others, augmented with additional ActionScript behaviour using MXML is as simple as can be. However, to create a component from scratch using ActionScript requires a lot of detailed knowledge of how the Flex framework works and the component life-cycle in particular.
The Flex documentation attempts to describe the lifecycle, but can leave the developer with lots of unanswered questions. When I got more involved in developing components I found chapter 19 of Programming Flex 3 good for filling in the gaps.
This week a new and free paper has been published by DevelopmentArc that also explores the component life-cycle and the application life-cycle. A very well worth while read….
Understanding the Adobe Flex® 3 Component and Framework Lifecycle
Feel free to post links to other compent lifecycle resrouces in the comments.