This is probably a well-duh to most of you but it took me a bit to figure out why I couldn’t get framework caching to work for my Flex Builder projects publishing to Flash Player 10.

Where I was using these files for Flash Player 9:

• framework_3.0.0.477.swf
• framework_3.0.0.477.swz

I now need these files for Flash Player 10

• framework_3.2.0.3794.swf
• rpc_3.2.0.3794.swf

You can find these files by going into your Flex Builder install folder and looking for the sdks folder. Mine is located here on a WinXP machine: C:\Program Files\Adobe\Flex Builder 3 Plug-in\sdks\3.2.0.3794\frameworks\rsls

The easiest way to do this is to add -static-rsls=false to the command line arguments and place the framework files in the folder where your SWFs are located.

I finally got around to using Flex framework caching on all my apps. Here’s a few little snags I ran across:

Don’t assume it works everywhere
Suppose you set up a project to use framework caching. You publish. You notice that your SWF is way smaller than before. ( Rejoice ) You upload your files, everything seems to work and you call it a day.

The problem is that you probably already have the Flex framework cached. So if it isn’t working you won’t know about it. I found this out by asking my wife to look at something I did with Flex and noticed that she got an error on the Flex preloader that said, “rsl error 1 of 1″.

My problem was that the Flex app was in a WordPress post and so the SWC files were not located in the same folder as the SWF. All I had to do was upload the framework_3.0.0.477.swf and framework_3.0.0.477.swz files to the root of my site. Problem solved.

If you want/need to delete your cached framework files for testing purposes then just go to the Global Storage Settings panel page and uncheck the Store common Flash components to reduce download times option. ( Usability note: I really wish there were a submit button or something on that panel. )

Lets see, what else went wrong? Well, nothing really. It was amazingly simple to implement. Makes me wish I’d done it years ago. Well, at least when it became available. Seems like years ago now. :-)

All I had to do was add -static-rsls=false to my command line and drop the SWC/SWZ files into my html-template folder. That was pretty much it.

You can read more about the Framework RSL at Adobe.

Addendum: I just added this post about framework caching for Flash Player 10.