CacheStorage.keys()
The
keys() method of the
CacheStorage interface returns a Promise that will
resolve with an array containing strings corresponding to all of the named
Cache objects tracked by the CacheStorage object in the
order they were created. Use this method to iterate over a list of all
Cache objects.
You can access CacheStorage through the global
caches property.
Syntax
caches.keys().then(function(keyList) {
//do something with your keyList
});
Parameters
None.
Return value
a Promise that resolves with an array of the Cache names
inside the CacheStorage object.
Examples
In this code snippet we wait for an activate event, and then run a
waitUntil() block that clears up any old,
unused caches before a new service worker is activated. Here we have an allowlist
containing the names of the caches we want to keep (cacheAllowlist). We
return the keys of the caches in the CacheStorage object using
keys(), then check each key to see if it is in the allowlist. If not, we
delete it using CacheStorage.delete().
this.addEventListener('activate', function(event) {
var cacheAllowlist = ['v2'];
event.waitUntil(
caches.keys().then(function(keyList) {
return Promise.all(keyList.map(function(key) {
if (cacheAllowlist.indexOf(key) === -1) {
return caches.delete(key);
}
}));
})
);
});
Specifications
| Specification |
|---|
| Service Workers 1 # cache-storage-keys |
Browser compatibility
BCD tables only load in the browser