Question

As the new Flex SDK 4.5 has become a stable release, I want to upgrade my apps to the new SDK. But without losing compilation with SDK 4.0 with which they are working perfectly well. I used Flash Builder 4.0 to build them. Is there a way in Flash Builder to conditionally compile with 4.0 and 4.5 and create two release versions in separate bin-debug folders?

Answer 1

Flash Builder supports multiple SDKs; but you can only use a single SDK per project. You have a few options:

1. Use a build tool such as ANT to create your builds. This is probably the most elegant, but probably requires the most setup.
2. Create two projects; one for each SDK. Point the source directory on each project to the same source. This will cause problems long term if you need to make SDK specific changes.
3. Switch SDKs on the project when you need to recompile with a different version. This is easy to do; but will be tedious if you do this a lot.

For Flextras components, I keep a different branch of the code for each SDK. This is because due to SDK changes, we often need different versions of code. As one example, with our Spark AutoComplete component, Flex 4.5 introduced a bug that was not there in Flex 4 or Flex 4.1. So we have a Flex 4 version and a Flex 4.5 version.

In most traditional application development, I would not expect it was important to support multiple SDKs w/ the same code base.