import { DomainObject } from './DomainObject'; export declare const MARK_AS_DOMAIN_EVENT: unique symbol; /** * In Domain Driven Design, an Event is a type of Domain Object for which: * - properties are immutable (e.g., something happened) * - identity does matter * - i.e., it is uniquely identified by what happened and to what * - i.e., if you change the uniquely identifying properties (when or to what) of an event, it will be considered a new event * - i.e., not all properties on the event uniquely identify the event * * The purpose of a Domain Event is to represent interesting things that happen in the domain. * * For example, * - An `ItemViewedEvent { itemUuid, customerUuid, occurredAt }` is an event. Changing when it `occurredAt` which `customerUuid` did it or which `itemUuid` it happened to would result in a new event. * - A `PowerSupplyMeasuredEvent { batteryUuid, current, voltage, temperature, occurredAt }` is an event. Changing when it `occurredAt` or which `batteryUuid` it occurred to would result in a new event. Note: changing the `current`, `voltage`, or `temperature` would _not_ result in a new event though, since only one measurement can be made at a time for a `batteryUuid` */ export declare abstract class DomainEvent> extends DomainObject { /** * DomainEvent marker symbol for cross-version compatibility. * * Uses Symbol.for() to create a global symbol that works across different versions * of the domain-objects library. The value is the version string. */ static readonly [MARK_AS_DOMAIN_EVENT]: string; /** * `DomainEvent.primary` defines the surrogate key of the domain.event, utilized as the primary key in persistance * * for example, * - a `FileProcessingJob { uuid, filePath, status }` is likely going to have a primary key of `uuid` * - a `GoogleAdsCampaign { resourceName, accountId, name }`, however, has a primary key of `resourceName` * * ref * - https://en.wikipedia.org/wiki/Surrogate_key */ static primary?: readonly [string]; /** * `DomainEvent.unique` defines the natural key of the domain.event, utilized as the unique key in persistance * * note, * - for domain.events, it should always include a timestamp. * * for example, * - a `FileOpenedEvent { fileUuid, userUuid, occurredAt }` is likely going to be unique on the all of the keys: the combination of `['fileUuid', 'userUuid', 'occurredAt']` uniquely identifies the event. * - an `AirComfortMeasuredEvent { locationUuid, sensorUuid, temperature, humidity, occurredAt }`, on the other hand, is likely only going to be unique on `['locationUuid', 'sensorUuid', 'occurredAt']`, because logically we cant have a measurement from the same `sensor` + `location` at the same `time` * * ref * - https://en.wikipedia.org/wiki/Natural_key */ static unique: readonly string[]; }