Catches in upgrading from Flex 2.0.1 to Flex 3.*?

Question

I ask this question in the hope of collecting all the incompatible changes/bugfixes in Flex 3.*, of which the maintainer of a Flex 2.0.1 application needs to be aware before upgrading. I'm thinking of issues of the following nature:

1. Bugs in 2.0.1 that had had some workaround, and have been fixed in 3.*, rendering the workaround not only useless but also erroneous.
2. Bugs introduced in 3.* that worked in 2.0.1, needing new workarounds.
3. Features that behave slightly differently (events, attributes, etc.).
4. Incompatible internal changes, that should not effect the progammer, unless they meddled a bit with the internal objects of the framework, like I did. :-)
5. Anything not fitting in any of these categories.

(I found several such issues, when I last tried this some time ago. Unfortunately I didn't take notes, and I forgot them since then, but I will update this post when I figure them out again. I reported one issue on the Adobe bug tracking site, it was unfortunately deferred.)

It would also be interesting to read about the advantages/drawbacks of such an upgrade. Are there any showstoppers?

Answer 1

here are some links that may help in your endeavors:

http://blogs.adobe.com/flexdoc/2008/02/migrating_from_flex_2_to_flex.html

http://blog.comtaste.com/2007/06/migrate_from_flex_2_to_flex_3.html

http://butterfliesandbugs.wordpress.com/category/flex-migration/

http://butterfliesandbugs.wordpress.com/2008/03/04/understanding-flex-3-migration-issues-part-i/

http://butterfliesandbugs.wordpress.com/2008/03/06/understanding-flex-3-migration-issues-part-ii/

http://butterfliesandbugs.wordpress.com/2008/03/16/understanding-flex-3-migration-issues-part-iii/

For the record, most of the migration problems from Flex 2 to 3 are minor, especially when compared to the problems of migrating from Flex 1.x to 2. I upgraded several applications with no problems at all. That being said, the above links should help note most of the problems you might run into.