From the beginning of my first Flex experiences I was suffering from that there wasn't any source code formatter of Flex Builder. Using Eclipse, I can format the source codes by only one right click.
But I was not able to format the source code of the Flex classes, components, mxmls... etc.
Today I searched about this topic in Google. And I found a plugin which can be plugged into Eclipse and formats the flex source codes.
The process list you should do is below:
1. Download the plugin.
2. Extract the files into the "C:\Program Files\Adobe\Flex Builder 3\plugins" directory. (Or your set up directory)
3. Restart the Flex Builder (or Eclipse if you are using Flex Builder as a plugin)
When the Flex Builder is restarted you will notice that 5 buttons will appear on the Toolbars Menu and two items on right click.
You can find detailed information about this tool at Flex Code Formatter.
In my opinion after formatting the source code, actionscript code segments looks nicer than mxml code segments. (P.S. : I only use it for actionscript codes.).
There isn't much people around me using this kind of tool and I am waiting for your comments after using this tool. I hope it will be a useful tool.