It’s ideal if you can get the iframe to tell you itself from a script inside the frame. For example it could call a parent function directly to tell it it’s ready. Care is always required with cross-frame code execution as things can happen in an order you don’t expect.
Then I had a few genius ideas along with (oh, I had this working in an older version of the software) experience. So to get to the point, a Django Media Sync processor finally allowed me to view the source code while debugging on the actual site. In contrast to setting breakpoints on lines thousands of characters long and reading alphabetized code. Just spending about 5 minutes glancing at the documentation and looking at the file for Closure compiler, I put these lines in a file called combine in my “Python27\Lib\site-packages\mediasync\processors” folder:
After adding it in my settings file, running the media sync command, and refreshing; a nice error message showed up in the console. I could finally put debug points in the deployed, combined script files!