How much of an impact will migrating to Flex 4 have on our code base? We have about 40k LOC written in Flex 3. I'm hoping that there are no breaking changes in the Flex SDK, and that we can smoothly transition to the new features of Flex 4 while minimizing any disruption. From what I've read Adobe is developing a new set of GUI components called 'Spark' but I'm hoping our existing stuff can co-exist with the new components.
+3
A:
Spark and MX components can co-exist within the same application (and even within the same MXML files). There are some changes to how CSS works because CSS namespaces are now supported, and you will encounter a small migration step there.
In terms of choosing Spark versus MX, Adobe recommends keeping your existing code that already uses MX components the same. There's no need to make everything Spark immediately. You can make incremental changes as the need arises. For new development, you should use Spark when possible. However, the Spark components in Flex 4 will not have 100% feature-parity with MX, so you will likely encounter some situations where you need to continue MX components for the time being.
joshtynjala
2009-10-30 19:02:50
+2
A:
You can move to Flex 4 without adopting any of the new stuff. You can keep the 2006 namespace so that you don't have to update your MXML files. Also you can optionally use the Spark components. The only major benefit of doing this is the faster compiler. It will also allow you to progressively move to the 2009 namespace and Spark.
James Ward
2009-10-30 19:33:28
James, can you elaborate what you mean by faster compiler? Are you saying MXML compilation is faster for Spark components, or that they are faster in performance once compiled to SWFs?
Pedro Estrada
2009-11-01 17:08:46
The Flex 4 compiler is faster overall - even when compiling Flex 3-based apps.
Marplesoft
2010-04-02 18:44:12