Posts in category flexibility

New Event Manager

Every part of Licorn® can now emit events, and any other part of it can setup a callback to receive the event arguments, to do what is needed. Events callbacks can be run synchronously (with method L_event_run()) or not (with method L_event_dispatch()). In this case, there is no guarantee of callback order call, jobs can be parallel because they are handled by the service facility. Example:

Emitter side: 

from licorn.daemon import priorities, InternalEvent

# L_event_dispatch is a builtin, defined by the daemon at start
# no need to import anything, to use it.

L_event_dispatch(priorities.NORMAL,
                 InternalEvent('main_configuration_file_changed'))

Receiver side: 

[...]

def main_configuration_file_changed_callback():
    """ this method will be auto-collected if the surrounding object 
        is a controller, or a CoreUnitObject whose controller defines
        self.__look_deeper_for_callbacks (typically ModulesManager 
        does it). """
    #
    # do whatever needed with LMC.configuration, whose
    # contents already reflect the change.

The EventManager is ready to operate even before the INotifier, and just after the LMC is setup. It will collect all callbacks of the controllers, backend and extensions on start.

It is stopped last, at the end of the daemon life.

Note: the InternalEvent instance can be given a callback argument (any callable() can apply for the job), to resync the Emitter at the end of event callback execution.