Cache.add() - Web APIs 编辑

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.

Syntax

cache.add(request).then(function() {
  // request has been added to the cache
});

Parameters

request

The request you want to add to the cache. This can be a  Request object or a URL.

Return value

A Promise that resolves with undefined.

Exceptions

Examples

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');
    })
  );
});

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Using Service Workers
• Cache
• WorkerGlobalScope.caches