Notification

from pymediate import Notification

class Notification: ...

Notification is the base class for messages published with Mediator.publish(). Publishing delivers a notification to every registered handler for its exact class and returns None. Zero handlers is valid.

Notifications have no response type parameter. The same Notification class is re-exported from pymediate and pymediate.sync. Its subscription registry is also shared, so all handlers for one exact notification type must be asynchronous or all must be synchronous.

Example

from dataclasses import dataclass

from pymediate import Notification


@dataclass(frozen=True)
class OrderPlaced(Notification):
    order_id: int
    item: str

Dispatch is exact: a handler registered for a base notification class does not receive instances of a derived notification class.

See also

• NotificationHandler — subscribes to one notification type
• Mediator.publish() — delivery and failure behavior
• Notifications — design and integration guidance