How to Use Event Module

In this document, you’ll learn about the different methods in the Event Module's service and how to use them.

Resolve Event Module's Service#

In your workflow's step, you can resolve the Event Module's service from the Medusa container:

Code
1import { Modules } from "@medusajs/framework/utils"2import { createStep } from "@medusajs/framework/workflows-sdk"3
4const step1 = createStep(5  "step-1",6  async ({}, { container }) => {7    const eventModuleService = container.resolve(8      Modules.EVENT9    )10    11    // TODO use eventModuleService12  } 13)

This will resolve the service of the configured Event Module, which is the Local Event Module by default.

You can then use the Event Module's service's methods in the step. The rest of this guide details these methods.

emit#

This method emits one or more events. Subscribers listening to the event(s) are executed asynchronously.

Example#

Code
1await eventModuleService.emit({ 2  name: "user.created", 3  data: { 4    user_id: "user_123"5  }6})

Type Parameters#

Parameters#

Returns#

subscribe#

This method adds a subscriber to an event. It's mainly used internally to register subscribers.

Example#

Code
1eventModuleService.subscribe("user.created", async (data) => {2  console.log("User created", data)3})

Parameters#

Returns#

unsubscribe#

This method removes a subscriber from an event. It's mainly used internally to unregister subscribers.

Example#

Code
1eventModuleService.unsubscribe("user.created", async (data) => {2  console.log("User created", data)3})

Parameters#

Returns#

releaseGroupedEvents#

This method emits all events in the specified group. Grouped events are useful when you have distributed transactions where you need to explicitly group, release and clear events upon lifecycle events of a transaction.

Example#

Code
await eventModuleService.releaseGroupedEvents("group_123")

Parameters#

Returns#

clearGroupedEvents#

This method removes all events in the specified group. Grouped events are useful when you have distributed transactions where you need to explicitly group, release and clear events upon lifecycle events of a transaction.

Example#

Code
await eventModuleService.clearGroupedEvents("group_123")

Parameters#

Returns#