---
displayed_sidebar: servicesSidebar
---

import ParameterTypes from "@site/src/components/ParameterTypes"

# EventBusService

Can keep track of multiple subscribers to different events and run the
subscribers when events happen. Events will run asynchronously.

## constructor

### Parameters

<ParameterTypes parameters={[{"name":"__namedParameters","type":"`InjectedDependencies`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"config","type":"[ConfigModule](../../medusa/interfaces/medusa.ConfigModule-1.mdx)","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"isSingleton","type":"`boolean`","description":"","optional":false,"defaultValue":"true","expandable":false,"children":[]}]}  sectionTitle="new EventBusService"/>

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## Properties

<ParameterTypes parameters={[{"name":"manager_","type":"`EntityManager`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"transactionManager_","type":"`undefined` \\| `EntityManager`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"__container__","type":"`any`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"config_","type":"[ConfigModule](../../medusa/interfaces/medusa.ConfigModule-1.mdx)","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"stagedJobService_","type":"[StagedJobService](services.StagedJobService.mdx)","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"logger_","type":"[Logger](../../medusa/interfaces/medusa.Logger-1.mdx)","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"shouldEnqueuerRun","type":"`boolean`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"enqueue_","type":"Promise&#60;void&#62;","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"__configModule__","type":"`Record<string, unknown>`","description":"","optional":true,"defaultValue":"","expandable":false,"children":[]},{"name":"__moduleDeclaration__","type":"`Record<string, unknown>`","description":"","optional":true,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="EventBusService"/>

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## Accessors

### activeManager\_

#### Returns

<ParameterTypes parameters={[{"name":"EntityManager","type":"`EntityManager`","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}  sectionTitle="activeManager_"/>

### eventBusModuleService\_

#### Returns

<ParameterTypes parameters={[{"name":"IEventBusModuleService","type":"`object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="eventBusModuleService_"/>

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## Methods

### shouldRetryTransaction\_

#### Parameters

<ParameterTypes parameters={[{"name":"err","type":"`Record<string, unknown>` \\| `object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="shouldRetryTransaction_"/>

#### Returns

<ParameterTypes parameters={[{"name":"boolean","type":"`boolean`","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}  sectionTitle="shouldRetryTransaction_"/>

### atomicPhase\_

Wraps some work within a transactional block. If the service already has
a transaction manager attached this will be reused, otherwise a new
transaction manager is created.

#### Type Parameters

<ParameterTypes parameters={[{"name":"TResult","type":"`object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"TError","type":"`object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="atomicPhase_"/>

#### Parameters

<ParameterTypes parameters={[{"name":"work","type":"(`transactionManager`: `EntityManager`) => Promise&#60;TResult&#62;","description":"the transactional work to be done","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"isolationOrErrorHandler","type":"`IsolationLevel` \\| (`error`: TError) => Promise&#60;void \\| TResult&#62;","description":"the isolation level to be used for the work.","optional":true,"defaultValue":"","expandable":false,"children":[]},{"name":"maybeErrorHandlerOrDontFail","type":"(`error`: TError) => Promise&#60;void \\| TResult&#62;","description":"Potential error handler","optional":true,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="atomicPhase_"/>

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;TResult&#62;","optional":false,"defaultValue":"","description":"the result of the transactional work","expandable":false,"children":[]}]}  sectionTitle="atomicPhase_"/>

### withTransaction

#### Parameters

<ParameterTypes parameters={[{"name":"transactionManager","type":"`EntityManager`","description":"","optional":true,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="withTransaction"/>

#### Returns

<ParameterTypes parameters={[{"name":"this","type":"`this`","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}  sectionTitle="withTransaction"/>

### subscribe

Adds a function to a list of event subscribers.

#### Parameters

<ParameterTypes parameters={[{"name":"event","type":"`string` \\| `symbol`","description":"the event that the subscriber will listen for.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"subscriber","type":"[Subscriber](../../types/EventBusTypes/types/types.EventBusTypes.Subscriber.mdx)&#60;unknown&#62;","description":"the function to be called when a certain event\nhappens. Subscribers must return a Promise.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"context","type":"[SubscriberContext](../../types/EventBusTypes/types/types.EventBusTypes.SubscriberContext.mdx)","description":"subscriber context","optional":true,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="subscribe"/>

#### Returns

<ParameterTypes parameters={[{"name":"this","type":"`this`","optional":false,"defaultValue":"","description":"this","expandable":false,"children":[]}]}  sectionTitle="subscribe"/>

### unsubscribe

Removes function from the list of event subscribers.

#### Parameters

<ParameterTypes parameters={[{"name":"event","type":"`string` \\| `symbol`","description":"the event of the subcriber.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"subscriber","type":"[Subscriber](../../types/EventBusTypes/types/types.EventBusTypes.Subscriber.mdx)&#60;unknown&#62;","description":"the function to be removed","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"context","type":"[SubscriberContext](../../types/EventBusTypes/types/types.EventBusTypes.SubscriberContext.mdx)","description":"subscriber context","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="unsubscribe"/>

#### Returns

<ParameterTypes parameters={[{"name":"this","type":"`this`","optional":false,"defaultValue":"","description":"this","expandable":false,"children":[]}]}  sectionTitle="unsubscribe"/>

### emit

`**emit**<TypeParameter T>(data): Promise&#60;void \| [StagedJob](../../entities/classes/entities.StagedJob.mdx)[]&#62;`

Calls all subscribers when an event occurs.

#### Type Parameters

<ParameterTypes parameters={[{"name":"T","type":"`object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="emit"/>

#### Parameters

<ParameterTypes parameters={[{"name":"data","type":"[EmitData](../../types/EventBusTypes/types/types.EventBusTypes.EmitData.mdx)&#60;T&#62;[]","description":"The data to use to process the events","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="emit"/>

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;void \\| [StagedJob](../../entities/classes/entities.StagedJob.mdx)[]&#62;","optional":false,"defaultValue":"","description":"the jobs from our queue","expandable":false,"children":[]}]}  sectionTitle="emit"/>

`**emit**<TypeParameter T>(data): Promise&#60;void \| [StagedJob](../../entities/classes/entities.StagedJob.mdx)[]&#62;`

#### Type Parameters

<ParameterTypes parameters={[{"name":"T","type":"`object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="emit"/>

#### Parameters

<ParameterTypes parameters={[{"name":"data","type":"[Message](../../types/EventBusTypes/types/types.EventBusTypes.Message.mdx)&#60;T&#62;[]","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="emit"/>

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;void \\| [StagedJob](../../entities/classes/entities.StagedJob.mdx)[]&#62;","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}  sectionTitle="emit"/>

`**emit**<TypeParameter T>(eventName, data, options?): Promise&#60;void \| [StagedJob](../../entities/classes/entities.StagedJob.mdx)&#62;`

Calls all subscribers when an event occurs.

#### Type Parameters

<ParameterTypes parameters={[{"name":"T","type":"`object`","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="emit"/>

#### Parameters

<ParameterTypes parameters={[{"name":"eventName","type":"`string`","description":"the name of the event to be process.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"data","type":"T","description":"the data to send to the subscriber.","optional":false,"defaultValue":"","expandable":false,"children":[]},{"name":"options","type":"`Record<string, unknown>`","description":"options to add the job with","optional":true,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="emit"/>

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;void \\| [StagedJob](../../entities/classes/entities.StagedJob.mdx)&#62;","optional":false,"defaultValue":"","description":"the job from our queue","expandable":false,"children":[]}]}  sectionTitle="emit"/>

### startEnqueuer

#### Returns

<ParameterTypes parameters={[{"name":"void","type":"`void`","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}  sectionTitle="startEnqueuer"/>

### stopEnqueuer

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;void&#62;","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}  sectionTitle="stopEnqueuer"/>

### enqueuer\_

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;void&#62;","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}  sectionTitle="enqueuer_"/>

### listJobs

#### Parameters

<ParameterTypes parameters={[{"name":"listConfig","type":"[FindConfig](../../medusa/interfaces/medusa.FindConfig.mdx)&#60;[StagedJob](../../entities/classes/entities.StagedJob.mdx)&#62;","description":"","optional":false,"defaultValue":"","expandable":false,"children":[]}]}  sectionTitle="listJobs"/>

#### Returns

<ParameterTypes parameters={[{"name":"Promise","type":"Promise&#60;never[] \\| [StagedJob](../../entities/classes/entities.StagedJob.mdx)[]&#62;","optional":false,"defaultValue":"","description":"","expandable":false,"children":[]}]}  sectionTitle="listJobs"/>