Flex design view not working for components with custom base class

Question

I have a Flex component that, instead of inheriting directly from Canvas, inherits from a custom class (MyBaseComponent ) that I wrote which in turn inherits from Canvas:

Canvas > MyBaseComponent > MyComponent (mxml)

Design view does not work for this control. I just get a blank gray screen. (It works if I use Canvas instead of my custom base class.) There are no errors and the project compiles and runs just fine.

Applications with custom base classes work in design view, so why not components? Is there something special that must be done in this case?

Here is how my component's mxml looks:

<?xml version="1.0" encoding="utf-8"?>
<Custom:MyBaseComponent xmlns:mx="http://www.adobe.com/2006/mxml" width="614" height="282" xmlns:Custom="MyCustomLib.*">
    ...
</Custom:MyBaseComponent>

Answer 1

You are correct, they don't work, never have all the way back the the Flex Builder 2 betas.

This was actually the topic of my first blog post ever. It has a hacky workaround that kind works if you're interested, but it's a bit long to post here:

http://www.rogue-development.com/blog2/2007/03/code-in-front/