Class: BroadcastCacheUpdate

Constructor

BroadcastCacheUpdate

new BroadcastCacheUpdate(options)

Construct a BroadcastCacheUpdate instance with a specific channelName to broadcast messages on

Parameter

options

Object

Values in options have the following properties:

Parameter

headersToCheck

Optional

Array of string

A list of headers that will be used to determine whether the responses differ.

generatePayload

Optional

string

A function whose return value will be used as the payload field in any cache update messages sent to the window clients.

Method

notifyIfUpdated

async

notifyIfUpdated(options) returns Promise

Compares two Responses and sends a message (via postMessage()) to all window clients if the responses differ (note: neither of the Responses can be opaque).

The message that's posted has the following format (where payload can be customized via the generatePayload option the instance is created with):

{
  type: 'CACHE_UPDATED',
  meta: 'workbox-broadcast-update',
  payload: {
    cacheName: 'the-cache-name',
    updatedURL: 'https://example.com/'
  }
}

Parameter

options

Object

Values in options have the following properties:

Parameter
oldResponse	Optional Response Cached response to compare.
newResponse	Response Possibly updated response to compare.
request	Request The request.
cacheName	string Name of the cache the responses belong to. This is included in the broadcast message.
event	Optional Event event An optional event that triggered this possible cache update.

Returns: Promise Resolves once the update is sent.