Module: workbox-precaching

workbox-precaching

module

Version     6.1.1

Most consumers of this module will want to use the precacheAndRoute() method to add assets to the cache and respond to network requests with these cached assets.

If you require more control over caching and routing, you can use the PrecacheController interface.

Classes

PrecacheController

Performs efficient precaching of assets.

PrecacheFallbackPlugin

PrecacheFallbackPlugin allows you to specify an "offline fallback" response to be used when a given strategy is unable to generate a response.

It does this by intercepting the handlerDidError plugin callback and returning a precached response, taking the expected revision parameter into account automatically.

Unless you explicitly pass in a PrecacheController instance to the constructor, the default instance will be used. Generally speaking, most developers will end up using the default.

PrecacheRoute

A subclass of Route that takes a PrecacheController instance and uses it to match incoming requests and handle fetching responses from the precache.

PrecacheStrategy

A Strategy implementation specifically designed to work with PrecacheController to both cache and fetch precached assets.

Note: an instance of this class is created automatically when creating a PrecacheController; it's generally not necessary to create this yourself.

Methods

addPlugins

static

addPlugins(plugins)

Adds plugins to the precaching strategy.

Parameter
plugins	Array of Object

addRoute

static

addRoute(options)

Add a fetch listener to the service worker that will respond to network requests with precached assets.

Requests for assets that aren't precached, the FetchEvent will not be responded to, allowing the event to fall through to other fetch event listeners.

Parameter
options	Optional Object See PrecacheRoute options.

cleanupOutdatedCaches

static

cleanupOutdatedCaches()

Adds an activate event listener which will clean up incompatible precaches that were created by older versions of Workbox.

createHandlerBoundToURL

static

createHandlerBoundToURL(url, fallbackToNetwork) returns module:workbox-routing~handlerCallback

Helper function that calls PrecacheController#createHandlerBoundToURL on the default PrecacheController instance.

If you are creating your own PrecacheController, then call the PrecacheController#createHandlerBoundToURL on that instance, instead of using this function.

Parameter
url	string The precached URL which will be used to lookup the Response.
fallbackToNetwork	Optional boolean Whether to attempt to get the response from the network if there's a precache miss.

Returns

module:workbox-routing~handlerCallback 

getCacheKeyForURL

static

getCacheKeyForURL(url) returns string

Takes in a URL, and returns the corresponding URL that could be used to lookup the entry in the precache.

If a relative URL is provided, the location of the service worker file will be used as the base.

For precached entries without revision information, the cache key will be the same as the original URL.

For precached entries with revision information, the cache key will be the original URL with the addition of a query parameter used for keeping track of the revision info.

Parameter
url	string The URL whose cache key to look up.

Returns

string The cache key that corresponds to that URL.

matchPrecache

static

matchPrecache(request) returns Promise containing (Response or undefined)

Helper function that calls PrecacheController#matchPrecache on the default PrecacheController instance.

If you are creating your own PrecacheController, then call PrecacheController#matchPrecache on that instance, instead of using this function.

Parameter
request	(string or Request) The key (without revisioning parameters) to look up in the precache.

Returns

Promise containing (Response or undefined) 

precache

static

precache(entries)

Adds items to the precache list, removing any duplicates and stores the files in the "precache cache" when the service worker installs.

This method can be called multiple times.

Please note: This method will not serve any of the cached files for you. It only precaches files. To respond to a network request you call addRoute().

If you have a single array of files to precache, you can just call precacheAndRoute().

Parameter
entries	Optional Array of (Object or string) Array of entries to precache.

precacheAndRoute

static

precacheAndRoute(entries, options)

This method will add entries to the precache list and add a route to respond to fetch events.

This is a convenience method that will call precache() and addRoute() in a single call.

Parameter
entries	Array of (Object or string) Array of entries to precache.
options	Optional Object See PrecacheRoute options.

Abstract types

CleanupResult

static

Object

Property

Parameter
deletedCacheRequests	Array of string List of URLs that were deleted while cleaning up the cache.

InstallResult

static

Object

Properties

Parameter
updatedURLs	Array of string List of URLs that were updated during installation.
notUpdatedURLs	Array of string List of URLs that were already up to date.

PrecacheEntry

static

Object

Properties

Parameter
url	string URL to precache.
revision	Optional string Revision information for the URL.
integrity	Optional string Integrity metadata that will be used when making the network request for the URL.

urlManipulation

inner

urlManipulation(context) returns Array of URL

The "urlManipulation" callback can be used to determine if there are any additional permutations of a URL that should be used to check against the available precached files.

For example, Workbox supports checking for '/index.html' when the URL '/' is provided. This callback allows additional, custom checks.

Parameter
context	Object Values in context have the following properties: Parameter url URL The request's URL.

Returns

Array of URL To add additional urls to test, return an Array of URLs. Please note that these should not be strings, but URL objects.