medusa-starter/src/subscribers

Custom subscribers

You may define custom eventhandlers, subscribers by creating files in the /subscribers directory.

import MyCustomService from "../services/my-custom";
import { EntityManager } from "typeorm";
import { OrderService } from "@medusajs/medusa";
import { IEventBusService } from "@medusajs/types";

export default class MySubscriber {
  protected readonly manager_: EntityManager;
  protected readonly myCustomService_: MyCustomService

  constructor(
    {
      manager,
      eventBusService,
      myCustomService,
    }: {
      manager: EntityManager;
      eventBusService: IEventBusService;
      myCustomService: MyCustomService;
    }
  ) {
    this.manager_ = manager;
    this.myCustomService_ = myCustomService;

    eventBusService.subscribe(OrderService.Events.PLACED, this.handleOrderPlaced);
  }

  handleOrderPlaced = async (data): Promise<any> => {
    return true;
  }
}

A subscriber is defined as a class which is registered as a subscriber by invoking eventBusService.subscribe in the constructor of the class.

The type of event that the subscriber subscribes to is passed as the first parameter to the eventBusService.subscribe and the eventhandler is passed as the second parameter. The types of events a service can emmit are described in the individual service.

An eventhandler has one parameter; a data object which contain information relating to the event, including relevant id's. The id can be used to fetch the appropriate entity in the eventhandler.