Finds the Cache entry whose key is the request, returning a Promise that resolves to true if a matching Cache entry is found and deleted. If no Cache entry is found, the promise resolves to false .
Takes both a request and its response and adds it to the given cache.
Takes an array of URLs, retrieves them, and adds the resulting response objects to the given cache.
Takes a URL, retrieves it and adds the resulting response object to the given cache. This is functionally equivalent to calling fetch() , then using put() to add the results to the cache.
Returns a Promise that resolves to an array of all matching responses in the Cache object.
Returns a Promise that resolves to the response associated with the first matching request in the Cache object.
This code snippet is from the service worker selective caching sample. (see selective caching live) The code uses CacheStorage.open() to open any Cache objects with a Content-Type header that starts with font/ .
The code then uses Cache.match() to see if there's already a matching font in the cache, and if so, returns it. If there isn't a matching font, the code fetches the font from the network and uses Cache.put() to cache the fetched resource.
The code handles exceptions thrown from the fetch() operation. Note that an HTTP error response (e.g., 404) will not trigger an exception. It will return a normal response object that has the appropriate error code.
The code snippet also shows a best practice for versioning caches used by the service worker. Though there's only one cache in this example, the same approach can be used for multiple caches. It maps a shorthand identifier for a cache to a specific, versioned cache name. The code also deletes all caches that aren't named in CURRENT_CACHES .
In the code example, caches is a property of the ServiceWorkerGlobalScope . It holds the CacheStorage object, by which it can access the CacheStorage interface.
Note: In Chrome, visit chrome://inspect/#service-workers and click on the "inspect" link below the registered service worker to view logging statements for the various actions the service-worker.js script is performing.