This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The add()
method of the Cache
interface takes a URL, retrieves it, and adds the resulting response object to the given cache. The add()
method is functionally equivalent to the following:
fetch(url).then(function(response) { if (!response.ok) { throw new TypeError('bad response status'); } return cache.put(url, response); })
For more complex operations, you'll need to use Cache.put()
directly.
Note: add()
will overwrite any key/value pair previously stored in the cache that matches the request.
Note: Initial Cache implementations (in both Blink and Gecko) resolve Cache.add
, Cache.addAll
, and Cache.put
promises when the response body is fully written to storage. More recent spec versions state that the browser can resolve the promise as soon as the entry is recorded in the database even if the response body is still streaming in.
cache.add(request).then(function() { // request has been added to the cache });
Request
object or a URL.A Promise
that resolves with void.
Exception | Happens when |
---|---|
TypeError | The URL scheme is not The Response status is not in the 200 range (i.e., not a successful response.) This occurs if the request does not return successfully, but also if the request is a cross-origin no-cors request (in which case the reported status is always 0.) |
This code block waits for an InstallEvent
to fire, then calls waitUntil()
to handle the install process for the app. This consists of calling CacheStorage.open
to create a new cache, then using Cache.add
to add an asset to it.
this.addEventListener('install', function(event) { event.waitUntil( caches.open('v1').then(function(cache) { return cache.add('/sw-test/index.html'); }) ); });
Specification | Status | Comment |
---|---|---|
Service Workers The definition of 'Cache' in that specification. | Editor's Draft | Initial definition. |
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 46 | (Yes) | (Yes)[1] | No support | 33 | No support |
Require HTTPS | 46 | (Yes) | (Yes)[1] | ? | 33 | ? |
TypeError if request is not successful | (Yes) | ? | 47.0 (47.0)[1] | (Yes) | (Yes) | (Yes) |
Feature | Android Webview | Chrome for Android | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | 46 | 46 | (Yes) | ? | No support | 33 | No support |
Require HTTPS | 46 | 46 | (Yes) | ? | ? | 33 | ? |
TypeError if request is not successful | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
[1] Service workers (and Push) have been disabled in the Firefox 45 & 52 Extended Support Releases (ESR.)
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Cache/add