def _decode_object(d):
topic = d['__class__']['topic']
state = d['__class__']['state']
obj_class = resolve_domain_topic(topic)
obj = object.__new__(obj_class)
obj.__dict__.update(state)
return obj
def _decode_object(d):
topic = d['__class__']['topic']
state = d['__class__']['state']
obj_class = resolve_domain_topic(topic)
obj = object.__new__(obj_class)
obj.__dict__.update(state)
return obj
def entity_from_snapshot(snapshot):
"""
Reconstructs domain entity from given snapshot.
"""
assert isinstance(snapshot, AbstractSnapshop), type(snapshot)
if snapshot.state is not None:
entity_class = resolve_domain_topic(snapshot.topic)
return reconstruct_object(entity_class, snapshot.state)
def test_topic_resolution_error(self):
# Check topic resolution error is raised, if the module path is
# broken, and if the class name is broken.
resolve_domain_topic('eventsourcing.domain.model.events#DomainEvent')
with self.assertRaises(TopicResolutionError):
resolve_domain_topic('eventsourcing.domain.model.broken#DomainEvent')
with self.assertRaises(TopicResolutionError):
resolve_domain_topic('eventsourcing.domain.model.events#Broken')
def test_topic_resolution_error(self):
# Check topic resolution error is raised, if the module path is
# broken, and if the class name is broken.
resolve_domain_topic('eventsourcing.domain.model.events#DomainEvent')
with self.assertRaises(TopicResolutionError):
resolve_domain_topic(
'eventsourcing.domain.model.broken#DomainEvent')
with self.assertRaises(TopicResolutionError):
resolve_domain_topic('eventsourcing.domain.model.events#Broken')
def deserialize_domain_event(stored_event,
json_decoder_cls=None,
without_json=False,
with_uuid1=False,
cipher=None,
always_encrypt=False):
"""
Recreates original domain event from stored event topic and event attrs.
"""
assert isinstance(stored_event, StoredEvent)
# Get the domain event class from the topic.
event_class = resolve_domain_topic(stored_event.event_topic)
if not isinstance(event_class, type):
raise ValueError("Event class is not a type: {}".format(event_class))
if not issubclass(event_class, DomainEvent):
raise ValueError(
"Event class is not a DomainEvent: {}".format(event_class))
# Deserialize event attributes from JSON, optionally decrypted with cipher.
event_attrs = stored_event.event_attrs
if not without_json:
if json_decoder_cls is None:
json_decoder_cls = ObjectJSONDecoder
if always_encrypt or event_class.always_encrypt:
if cipher is None:
raise ValueError("Can't decrypt stored event without a cipher")
event_attrs = cipher.decrypt(event_attrs)
event_attrs = json.loads(event_attrs, cls=json_decoder_cls)
# Set the domain event ID.
if with_uuid1:
event_attrs['domain_event_id'] = stored_event.event_id
# Reinstantiate and return the domain event object.
try:
domain_event = object.__new__(event_class)
domain_event.__dict__.update(event_attrs)
except TypeError:
raise ValueError("Unable to instantiate class '{}' with data '{}'"
"".format(stored_event.event_topic, event_attrs))
return domain_event
def deserialize_domain_entity(entity_topic, entity_attrs):
"""
Return a new domain entity object from a given topic (a string) and attributes (a dict).
"""
# Get the domain entity class from the entity topic.
domain_class = resolve_domain_topic(entity_topic)
# Instantiate the domain entity class.
entity = object.__new__(domain_class)
# Set the attributes.
entity.__dict__.update(entity_attrs)
# Return a new domain entity object.
return entity
def deserialize_domain_entity(entity_topic, entity_attrs):
"""
Return a new domain entity object from a given topic (a string) and attributes (a dict).
"""
# Get the domain entity class from the entity topic.
domain_class = resolve_domain_topic(entity_topic)
# Instantiate the domain entity class.
entity = object.__new__(domain_class)
# Set the attributes.
entity.__dict__.update(entity_attrs)
# Return a new domain entity object.
return entity
def from_sequenced_item(self, sequenced_item):
"""
Reconstructs domain event from stored event topic and
event attrs. Used in the event store when getting domain events.
"""
assert isinstance(sequenced_item, self.sequenced_item_class), (self.sequenced_item_class, type(sequenced_item))
# Get the domain event class from the topic.
topic = getattr(sequenced_item, self.field_names.topic)
domain_event_class = resolve_domain_topic(topic)
# Deserialize, optionally with decryption.
is_encrypted = self.is_encrypted(domain_event_class)
event_attrs = self.deserialize_event_attrs(getattr(sequenced_item, self.field_names.data), is_encrypted)
# Reconstruct the domain event object.
return reconstruct_object(domain_event_class, event_attrs)
def deserialize_domain_event(stored_event, json_decoder_cls=None, without_json=False, with_uuid1=False, cipher=None,
always_encrypt=False):
"""
Recreates original domain event from stored event topic and event attrs.
"""
assert isinstance(stored_event, StoredEvent)
# Get the domain event class from the topic.
event_class = resolve_domain_topic(stored_event.event_topic)
if not isinstance(event_class, type):
raise ValueError("Event class is not a type: {}".format(event_class))
if not issubclass(event_class, DomainEvent):
raise ValueError("Event class is not a DomainEvent: {}".format(event_class))
# Deserialize event attributes from JSON, optionally decrypted with cipher.
event_attrs = stored_event.event_attrs
if not without_json:
if json_decoder_cls is None:
json_decoder_cls = ObjectJSONDecoder
if always_encrypt or event_class.always_encrypt:
if cipher is None:
raise ValueError("Can't decrypt stored event without a cipher")
event_attrs = cipher.decrypt(event_attrs)
event_attrs = json.loads(event_attrs, cls=json_decoder_cls)
# Set the domain event ID.
if with_uuid1:
event_attrs['domain_event_id'] = stored_event.event_id
# Reinstantiate and return the domain event object.
try:
domain_event = object.__new__(event_class)
domain_event.__dict__.update(event_attrs)
except TypeError:
raise ValueError("Unable to instantiate class '{}' with data '{}'"
"".format(stored_event.event_topic, event_attrs))
return domain_event
def class_from_topic(self, topic):
return resolve_domain_topic(topic)
