As a Flex developer, the debugger built into Flex Builder is an invaluable tool for development. This works well for local development, but when I was trying to debug issues that were only occurring after packaging the Flex app into a war file and deploying on a WebLogic server, I found the lack of debugging ability to be quite annoying! I was going through the process of making a 20 second code change, then a 2 minute package and deploy turnaround, read the traces I’d just put in from the Flash debug log, and repeat. Again. And again. Not the most productive (or enjoyable) way of debugging!
Then a co-worker showed me a trick he uses to connect the debugger to the Flex app, even though it’s running on another server and buried in a war. Firstly, create a new debug profile for the application and set the URL to about:blank. Save the profile, then run it. Flex Builder waits until it can make a connection with the application, but since the URL it tries to run is only about:blank, nothing is launched. However, if you open the browser you’ve set as the Flex Builder default and then browse to the URL of the remote app you’re trying to debug, Flex Builder will hook the debugger up to the browser and all is happy again!