workbox.strategies.NetworkFirst

class   static
Version     v4.3.1

An implementation of a network first request strategy.

By default, this strategy will cache responses with a 200 status code as well as opaque responses. Opaque responses are are cross-origin requests where the response doesn't support CORS.

If the network request fails, and there is no cache match, this will throw a WorkboxError exception.

Constructor

NetworkFirst

new NetworkFirst(options)

Parameter

options

Object

Values in options have the following properties:

Parameter

cacheName

string

Cache name to store and retrieve requests. Defaults to cache names provided by workbox-core.

plugins

Array of Object

Plugins to use in conjunction with this caching strategy.

fetchOptions

Object

Values passed along to the init of all fetch() requests made by this strategy.

matchOptions

Object

CacheQueryOptions

networkTimeoutSeconds

number

If set, any network requests that fail to respond within the timeout will fallback to the cache.

This option can be used to combat " lie-fi" scenarios.

Methods

handle

async

handle(options) returns Promise containing Response

This method will perform a request strategy and follows an API that will work with the Workbox Router.

Parameter

options

Object

Values in options have the following properties:

Parameter

request

Request

The request to run this strategy for.

event

Optional

Event

The event that triggered the request.
Returns

Promise containing Response 

makeRequest

async

makeRequest(options) returns Promise containing Response

This method can be used to perform a make a standalone request outside the context of the Workbox Router.

See "Advanced Recipes" for more usage information.

Parameter

options

Object

Values in options have the following properties:

Parameter

request

(Request or string)

Either a Request object, or a string URL, corresponding to the request to be made.

event

Optional

FetchEvent

If provided, event.waitUntil() will be called automatically to extend the service worker's lifetime.
Returns

Promise containing Response