Baseline Widely available
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Web Workers.
The has()
method of the CacheStorage
interface returns a Promise
that resolves to true
if a Cache
object matches the cacheName
.
You can access CacheStorage
through the Window.caches
property in windows or through the WorkerGlobalScope.caches
property in workers.
cacheName
A string representing the name of the Cache
object you are looking for in the CacheStorage
.
a Promise
that resolves to true
if the cache exists or false
if not.
The following example first checks whether a cache called 'v1' exists. If so, we add a list of assets to it. If not then we run some kind of cache set-up function.
caches
.has("v1")
.then((hasCache) => {
if (!hasCache) {
someCacheSetupFunction();
} else {
caches.open("v1").then((cache) => cache.addAll(myAssets));
}
})
.catch(() => {
// Handle exception here.
});
Specifications Browser compatibility See also
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
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HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4