In moving to compiling projects with the new Flex SDK 4, I noticed a couple of gotchas to do with the EMBED metatag that I thought I’d share:
Runtime Shared Libraries
If you wish to embed assets in your SWF with the EMBED metatag, so you can manage and update things easily, there’s an extra compiler parameter you must add, in order for your project to compile properly:
This is already added as a new default parameter in FlashDevelop projects. But if you’re planning to build projects from outside a similar IDE, you must add this to your compiler string. Otherwise, the compiler will think you have uninitialised constants and warn you so.
Using the EMBED metatag, or even better runtime loading, for fonts is the sensible way forward. The amount of projects I’ve seen where you need to build from an FLA file full of fonts, which you need to hunt down and install is crazy. With Flex SDK 4, you’ll need to add an extra attribute to your embed tag for fonts, called ’embedAsCFF’:
[Embed(source='myfont.ttf', fontName='MY_FONT', fontWeight='regular', unicodeRange='U+0020-U+0040,U+0041-U+005A', mimeType='application/x-font', embedAsCFF='false')] public static const MY_FONT :Class;