edx/XBlock — pull request #211 by gwprice (2014-05-05 21:13:05+00:00)
Title: Improve json_handler decorator

It will now sanely respond with a 400 error if the input is invalid, and
the wrapped function can indicate by raising a certain exception that a
status code other than 200 or 500 should be returned.

@cpennington @nedbat