Here are a few more things that tips for migrating your Flex 2 application to Flex 3:
1. If you are using runtime CSS, be sure to recompile not just your Flex Application, but, also your .css files with Flex 3. You will most likely get an unexpected error if your Application is compiled in Flex 3 and your css swf was compiled in Flex 2.
2. Recompile all of your swcs and modules in Flex 3, as well. If these swcs or modules use Binding, they cause errors in Flex 3 applications if they were compiled in 2. Note, Flex 2 resource bundle SWCs should be usable in a Flex 3 application.
3. When using HTTPService to send/receive XML data, be sure that your contentType=
application/xml. The default is contentType=
application/x-www-form-urlencoded. The default used to work in Flex 2 even if you were sending XML. In Flex 3, it doesn’t work out as pointed out by one of our customers in bug SDK-14811. For more details, please check out that bug.
4. To find out more about backwards compatibility issues that are actually bugs, you should search the public Jira bugbase for “regressions”. Regressions are bugs that exist in Flex 3 that worked correctly in Flex 2. To search for regressions, do the following:
– Go to http://bugs.adobe.com/flex and login. Register, if you have not registered yet.
– From the menu bar at the top, select “Find Issues”.
– Specify your search requirements on the left. Be sure to look under “Custom Fields” and find the “Regression” field. Select “yes”. Under “Issue Attributes”, look for the “Resolutions” field and select the last option “Deferred”.
– Click the “View” button at the top or bottom of the search criteria.
* This search will give you all of the regressions that were not fixed and therefore “deferred”.