def fire(self, name, *params):
"""Calls all callbacks with given event name.
Keyword arguments:
name -- Event name to fire.
params -- Params to pass to callbacks.
Raises:
EventDoesNotExistError -- If fire is called a nonexistent event.
Returns:
boolean -- Whether a callback (or multiple) was called successfully.
"""
self.logger.debug("Attempting to fire event: %s" % name)
if name not in self.registered_events:
self.logger.debug("Event does not exist: %s" % name)
raise EventDoesNotExistError(
"Can't call an event that does not exist: %s" % name
)
callbacks = self.registered_callbacks[name]
self.logger.info(
"Calling %d callbacks for event: %s" %
(len(callbacks), name)
)
accepted = False
for callback_id, callback in callbacks.iteritems():
try:
callback(self.cardinal, *params)
self.logger.debug(
"Callback %s accepted event: %s" %
(callback_id, name)
)
accepted = True
# If this exception is received, the plugin told us not to set the
# called flag true, so we can just log it and continue on. This
# might happen if a plugin realizes the event does not apply to it
# and wants the original caller to handle it normally.
except EventRejectedMessage:
self.logger.debug(
"Callback %s rejected event: %s" %
(callback_id, name)
)
except Exception:
self.logger.exception(
"Exception during callback %s for event: %s" %
(callback_id, name)
)
return accepted
def remove(self, name):
"""Removes a registered event."""
self.logger.debug("Attempting to unregister event: %s" % name)
if name not in self.registered_events:
self.logger.debug("Event does not exist: %s" % name)
raise EventDoesNotExistError("Can't remove nonexistent event: %s" %
name)
del self.registered_events[name]
del self.registered_callbacks[name]
self.logger.info("Removed event: %s" % name)
def fire(self, name, *params):
"""Calls all callbacks with given event name.
Keyword arguments:
name -- Event name to fire.
params -- Params to pass to callbacks.
Raises:
EventDoesNotExistError -- If fire is called a nonexistent event.
Returns:
boolean -- Whether a callback (or multiple) was called successfully.
"""
self.logger.debug("Attempting to fire event: %s" % name)
if name not in self.registered_events:
self.logger.debug("Event does not exist: %s" % name)
raise EventDoesNotExistError(
"Can't call an event that does not exist: %s" % name)
callbacks = self.registered_callbacks[name]
self.logger.debug("Calling %d callbacks for event: %s" %
(len(callbacks), name))
cb_deferreds = []
for callback_id, callback in callbacks.items():
d = defer.maybeDeferred(callback, self.cardinal, *params)
# It is necessary to pass callback_id in to this function in order
# to make sure it doesn't change when the loop iterates
def success(_result, callback_id=callback_id):
self.logger.debug("Callback {} accepted event '{}'".format(
callback_id, name))
return True
d.addCallback(success)
# It is necessary to pass callback_id in to this function in order
# to make sure it doesn't change when the loop iterates
def eventRejectedErrback(failure, callback_id=callback_id):
# If this exception is received, the plugin told us not to set
# the called flag true, so we can just log it and continue on.
# This might happen if a plugin realizes the event does not
# apply to it and wants the original caller to handle it
# normally.
failure.trap(EventRejectedMessage)
self.logger.debug("Callback {} rejected event '{}'".format(
callback_id, name))
return False
d.addErrback(eventRejectedErrback)
# It is necessary to pass callback_id in to this function in order
# to make sure it doesn't change when the loop iterates
def errback(failure, callback_id=callback_id):
self.logger.error(
"Unhandled error during callback {} for event '{}': {}".
format(callback_id, name, failure))
return False
d.addErrback(errback)
cb_deferreds.append(d)
dl = defer.DeferredList(cb_deferreds)
dl.addCallback(self._reduce_callback_accepted_statuses)
return dl