service-workers.md

Class: ServiceWorkers

Query and receive events from a sessions active service workers.

Process: Main
This class is not exported from the 'electron' module. It is only available as a return value of other methods in the Electron API.

Instances of the ServiceWorkers class are accessed by using serviceWorkers property of a Session.

For example:

const { session } = require('electron')

// Get all service workers.
console.log(session.defaultSession.serviceWorkers.getAllRunning())

// Handle logs and get service worker info
session.defaultSession.serviceWorkers.on('console-message', (event, messageDetails) => {
  console.log(
    'Got service worker message',
    messageDetails,
    'from',
    session.defaultSession.serviceWorkers.getFromVersionID(messageDetails.versionId)
  )
})

Instance Events

The following events are available on instances of ServiceWorkers:

Event: 'console-message'

Returns:

• event Event
• messageDetails Object - Information about the console message
  • message string - The actual console message
  • versionId number - The version ID of the service worker that sent the log message
  • source string - The type of source for this message. Can be javascript, xml, network, console-api, storage, rendering, security, deprecation, worker, violation, intervention, recommendation or other.
  • level number - The log level, from 0 to 3. In order it matches verbose, info, warning and error.
  • sourceUrl string - The URL the message came from
  • lineNumber number - The line number of the source that triggered this console message

Emitted when a service worker logs something to the console.

Event: 'registration-completed'

Returns:

• event Event
• details Object - Information about the registered service worker
  • scope string - The base URL that a service worker is registered for

Emitted when a service worker has been registered. Can occur after a call to navigator.serviceWorker.register('/sw.js') successfully resolves or when a Chrome extension is loaded.

Instance Methods

The following methods are available on instances of ServiceWorkers:

serviceWorkers.getAllRunning()

Returns Record<number, ServiceWorkerInfo> - A ServiceWorkerInfo object where the keys are the service worker version ID and the values are the information about that service worker.

serviceWorkers.getFromVersionID(versionId)

• versionId number

Returns ServiceWorkerInfo - Information about this service worker

If the service worker does not exist or is not running this method will throw an exception.