Cache.add()

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

Exception Happens when
TypeError

The URL scheme is not http or https.

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.)

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

Specification Status Comment
Service Workers
The definition of 'Cache: add' in that specification.
Working Draft Initial definition.

Browser compatibility

BCD tables only load in the browser

See also