web api instance method
Cache: add() method
Secure contextAvailable in workers
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((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
add(request)
Parameters
request-
: A request for the resource you want to add to the cache. This can be a
Requestobject or a URL.This parameter is used as a parameter to the
Request()constructor, so URLs follow the same rules as for that constructor. In particular, URLs may be relative to the base URL, which is the document’sbaseURIin a window context, orlocationin a worker context.
-
Return value
A Promise that resolves with undefined.
Exceptions
TypeError-
: The URL scheme is not
httporhttps.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 open to create a new cache, then using Cache.add to add an asset to it.
this.addEventListener("install", (event) => {
event.waitUntil(caches.open("v1").then((cache) => cache.add("/index.html")));
});