class obelus.common.Handler

A Handler holds callbacks which will be called when an ongoing operation terminates. Also known as Future, Promise, Deferred, etc.

Generally, you won’t create Handler objects yourself. Instead, a producer will create it for you, and you will set the on_result and on_exception attributes to be notified of the output of the operation.

classmethod aggregate(handlers)

Return a new Handler which will trigger when all the given handlers have successfully fired, or when one of them fails.


Failure callback. Will be called with the handler’s exception if the underlying operation failed.


Success callback. Will be called with the handler’s result if the underlying operation was successful.