def propagate(self, event):
"""
Re-emit state change for the derived properties as Derived*Event's.
TODO: We should fetch the old and new state of the namespace item in
stead of the old and new values of the item that changed.
If multiplicity is [0..1]:
send DerivedSetEvent if len(union) < 2
if multiplicity is [*]:
send DerivedAddEvent and DerivedDeleteEvent
if value not in derived union and
"""
if event.property in self.subsets:
# Make sure unions are created again
self.version += 1
if not IAssociationChangeEvent.providedBy(event):
return
# mimic the events for Set/Add/Delete
if self.upper == 1:
# This is a [0..1] event
# TODO: This is an error: [0..*] associations may be used for updating [0..1] associations
assert IAssociationSetEvent.providedBy(event)
old_value, new_value = event.old_value, event.new_value
self.handle(
DerivedSetEvent(event.element, self, old_value, new_value))
else:
if IAssociationSetEvent.providedBy(event):
old_value, new_value = event.old_value, event.new_value
# Do a filter? Change to
self.handle(
DerivedDeleteEvent(event.element, self, old_value))
self.handle(DerivedAddEvent(event.element, self,
new_value))
elif IAssociationAddEvent.providedBy(event):
new_value = event.new_value
self.handle(DerivedAddEvent(event.element, self,
new_value))
elif IAssociationDeleteEvent.providedBy(event):
old_value = event.old_value
self.handle(
DerivedDeleteEvent(event.element, self, old_value))
elif IAssociationChangeEvent.providedBy(event):
self.handle(DerivedChangeEvent(event.element, self))
else:
log.error("Don"
"t know how to handle event " + str(event) +
" for derived union")
def propagate(self, event):
if event.property is self.original and isinstance(
event.element, self.decl_class):
# mimic the events for Set/Add/Delete
if IAssociationSetEvent.providedBy(event):
self.handle(
RedefineSetEvent(event.element, self, event.old_value,
event.new_value))
elif IAssociationAddEvent.providedBy(event):
self.handle(
RedefineAddEvent(event.element, self, event.new_value))
elif IAssociationDeleteEvent.providedBy(event):
self.handle(
RedefineDeleteEvent(event.element, self, event.old_value))
else:
log.error("Don"
"t know how to handle event " + str(event) +
" for redefined association")
def on_element_change_event(self, event):
# self.logger.info('Handling IElementChangeEvent')
# self.logger.debug('Element is %s' % event.element)
# self.logger.debug('Property is %s' % event.property)
handlers = self._handlers.get((event.element, event.property))
if handlers:
# log.debug('')
# log.debug('Element change for %s %s [%s]' % (str(type(event)), event.element, event.property))
# if hasattr(event, 'old_value'):
# log.debug(' old value: %s' % (event.old_value))
# if hasattr(event, 'new_value'):
# log.debug(' new value: %s' % (event.new_value))
for handler in six.iterkeys(handlers):
try:
handler(event)
except Exception as e:
self.logger.error(
"Problem executing handler {0}, {1}".format(
handler, e))
# Handle add/removal of handlers based on the kind of event
# Filter out handlers that have no remaining properties
if IAssociationSetEvent.providedBy(event):
for handler, remainders in six.iteritems(handlers):
if remainders and event.old_value:
for remainder in remainders:
self._remove_handlers(event.old_value,
remainder[0], handler)
if remainders and event.new_value:
for remainder in remainders:
self._add_handlers(event.new_value, remainder,
handler)
elif IAssociationAddEvent.providedBy(event):
for handler, remainders in six.iteritems(handlers):
for remainder in remainders:
self._add_handlers(event.new_value, remainder, handler)
elif IAssociationDeleteEvent.providedBy(event):
for handler, remainders in six.iteritems(handlers):
for remainder in remainders:
self._remove_handlers(event.old_value, remainder[0],
handler)
def on_element_change_event(self, event):
#self.logger.info('Handling IElementChangeEvent')
#self.logger.debug('Element is %s' % event.element)
#self.logger.debug('Property is %s' % event.property)
handlers = self._handlers.get((event.element, event.property))
if handlers:
#log.debug('')
#log.debug('Element change for %s %s [%s]' % (str(type(event)), event.element, event.property))
#if hasattr(event, 'old_value'):
# log.debug(' old value: %s' % (event.old_value))
#if hasattr(event, 'new_value'):
# log.debug(' new value: %s' % (event.new_value))
for handler in handlers.iterkeys():
try:
handler(event)
except Exception, e:
self.logger.error('Problem executing handler %s' % handler, e)
# Handle add/removal of handlers based on the kind of event
# Filter out handlers that have no remaining properties
if IAssociationSetEvent.providedBy(event):
for handler, remainders in handlers.iteritems():
if remainders and event.old_value:
for remainder in remainders:
self._remove_handlers(event.old_value, remainder[0], handler)
if remainders and event.new_value:
for remainder in remainders:
self._add_handlers(event.new_value, remainder, handler)
elif IAssociationAddEvent.providedBy(event):
for handler, remainders in handlers.iteritems():
for remainder in remainders:
self._add_handlers(event.new_value, remainder, handler)
elif IAssociationDeleteEvent.providedBy(event):
for handler, remainders in handlers.iteritems():
for remainder in remainders:
self._remove_handlers(event.old_value, remainder[0], handler)
def propagate(self, event):
"""
Re-emit state change for the derived union (as Derived*Event's).
TODO: We should fetch the old and new state of the namespace item in
stead of the old and new values of the item that changed.
If multiplicity is [0..1]:
send DerivedSetEvent if len(union) < 2
if multiplicity is [*]:
send DerivedAddEvent and DerivedDeleteEvent
if value not in derived union and
"""
if event.property in self.subsets:
# Make sure unions are created again
self.version += 1
if not IAssociationChangeEvent.providedBy(event):
return
values = self._union(event.element, exclude=event.property)
if self.upper == 1:
assert IAssociationSetEvent.providedBy(event)
old_value, new_value = event.old_value, event.new_value
# This is a [0..1] event
if self.single:
# Only one subset element, so pass the values on
self.handle(
DerivedSetEvent(event.element, self, old_value,
new_value))
else:
new_values = set(values)
if new_value:
new_values.add(new_value)
if len(new_values) > 1:
# In an in-between state. Do not emit notifications
return
if values:
new_value = next(iter(values))
self.handle(
DerivedSetEvent(event.element, self, old_value,
new_value))
else:
if IAssociationSetEvent.providedBy(event):
old_value, new_value = event.old_value, event.new_value
if old_value and old_value not in values:
self.handle(
DerivedDeleteEvent(event.element, self, old_value))
if new_value and new_value not in values:
self.handle(
DerivedAddEvent(event.element, self, new_value))
elif IAssociationAddEvent.providedBy(event):
new_value = event.new_value
if new_value not in values:
self.handle(
DerivedAddEvent(event.element, self, new_value))
elif IAssociationDeleteEvent.providedBy(event):
old_value = event.old_value
if old_value not in values:
self.handle(
DerivedDeleteEvent(event.element, self, old_value))
elif IAssociationChangeEvent.providedBy(event):
self.handle(DerivedChangeEvent(event.element, self))
else:
log.error("Don"
"t know how to handle event " + str(event) +
" for derived union")