How to register a handler to a Domain Event?

To register a handler to Domain Event, from another class, we can pass a callback to the register method along with the Domain Event we're interested in being notified about.

// shared/domain/events/DomainEvents.ts

export class DomainEvents {
  private static handlersMap = {};
  private static markedAggregates: AggregateRoot<any>[] = [];


  public static register(
    callback: (event: IDomainEvent) => void,
    eventClassName: string
  ): void {
    if (!this.handlersMap.hasOwnProperty(eventClassName)) {
      this.handlersMap[eventClassName] = [];


It accepts both a callback function and the eventClassName, which is the name of the class (we can get that using

When we register a handler for a domain event, it gets added to the handlersMap.

For 3 different domain…

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