sw-toolbox

Options

All options can be specified globally via properties of toolbox.options. Any individual options can be configured on a per-handler basis, via the Object passed as the third parameter to toolbox.router methods.

debug [Boolean]

Determines whether extra information is logged to the browser’s console.

Default: false

networkTimeoutSeconds [Number]

A timeout that applies to the toolbox.networkFirst built-in handler. If networkTimeoutSeconds is set, then any network requests that take longer than that amount of time will automatically fall back to the cached response if one exists. When networkTimeoutSeconds is not set, the browser’s native networking timeout logic applies.

Default: null

cache [Object]

Various properties of cache control the behavior of the default cache when set via toolbox.options.cache, or the cache used by a specific request handler.

cache.name [String]

The name of the Cache used to store Response objects. Using a unique name allows you to customize the cache’s maximum size and age of entries.

Default: Generated at runtime based on the service worker’s registration.scope value.

cache.maxEntries [Number]

Imposes a least-recently used cache expiration policy on entries cached via the various built-in handlers. You can use this with a cache that’s dedicated to storing entries for a dynamic set of resources with no natural limit. Setting cache.maxEntries to, e.g., 10 would mean that after the 11th entry is cached, the least-recently used entry would be automatically deleted. The cache should never end up growing beyond cache.maxEntries entries. This option will only take effect if cache.name is also set. It can be used alone or in conjunction with cache.maxAgeSeconds.

Default: null

cache.maxAgeSeconds [Number]

Imposes a maximum age for cache entries, in seconds. You can use this with a cache that’s dedicated to storing entries for a dynamic set of resources with no natural limit. Setting cache.maxAgeSeconds to, e.g., 60 * 60 * 24 would mean that any entries older than a day would automatically be deleted. This option will only take effect if cache.name is also set. It can be used alone or in conjunction with cache.maxEntries.

Default: null

cache.queryOptions [Object]

If provided, this value will be passed in as the CacheQueryOptions whenever one of the handlers calls cache.match(). For example, setting

cache: {
  queryOptions: {
    ignoreSearch: true
  }
}

will cause cache matching to ignore URL query parameters present in the request.

Default: null

Handlers

There are five built-in handlers to cover the most common network strategies. For more information about offline strategies see the Offline Cookbook.

toolbox.networkFirst

Try to handle the request by fetching from the network. If it succeeds, store the response in the cache. Otherwise, try to fulfill the request from the cache. This is the strategy to use for basic read-through caching. It’s also good for API requests where you always want the freshest data when it is available but would rather have stale data than no data.

toolbox.cacheFirst

If the request matches a cache entry, respond with that. Otherwise try to fetch the resource from the network. If the network request succeeds, update the cache. This option is good for resources that don’t change, or have some other update mechanism.

toolbox.fastest

Request the resource from both the cache and the network in parallel. Respond with whichever returns first. Usually this will be the cached version, if there is one. On the one hand this strategy will always make a network request, even if the resource is cached. On the other hand, if/when the network request completes the cache is updated, so that future cache reads will be more up-to-date.

toolbox.cacheOnly

Resolve the request from the cache, or fail. This option is good for when you need to guarantee that no network request will be made, for example saving battery on mobile.

toolbox.networkOnly

Handle the request by trying to fetch the URL from the network. If the fetch fails, fail the request. Essentially the same as not creating a route for the URL at all.

Methods

toolbox.router.<get|post|put|delete|head>(urlPattern, handler, options)

Create a route that causes requests for URLs matching urlPattern to be resolved by calling handler. Matches requests using the GET, POST, PUT, DELETE or HEAD HTTP methods respectively.

• urlPattern - an Express style route. See the docs for the path-to-regexp module for the full syntax
• handler - a request handler, as described above
• options - an object containing options for the route. This options object will be passed to the request handler. The origin option is specific to the router methods, and can be either an exact string or a Regexp against which the origin of the Request must match for the route to be used.

toolbox.router.any(urlPattern, handler, options)

Like toolbox.router.get, etc., but matches any HTTP method.

toolbox.router.default

Takes a function to use as the request handler for any GET request that does not match a route.

toolbox.precache(arrayOfURLs)

Add each URL in arrayOfURLs to the list of resources that should be cached during the service worker install step. URLs in the array can either be a String or Request object. Note that this needs to be called before the install event is triggered, so you should do it on the first run of your script.

toolbox.cache(url, options)

Causes the resource at url to be added to the cache and returns a Promise that resolves with void. The options parameter supports the debug and cache global options.

toolbox.uncache(url, options)

Causes the resource at url to be removed from the cache and returns a Promise that resolves to true if the cache entry is deleted. The options parameter supports the debug and cache global options.