This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The cache
read-only property of the Request
interface contains the cache mode of the request. It controls how the request will interact with the browser's HTTP cache.
var currentCacheMode = request.cache;
A RequestCache
value. The available values are:
default
— The browser looks for a matching request in its HTTP cache. no-store
— The browser fetches the resource from the remote server without first looking in the cache, and will not update the cache with the downloaded resource.reload
— The browser fetches the resource from the remote server without first looking in the cache, but then will update the cache with the downloaded resource.no-cache
— The browser looks for a matching request in its HTTP cache. force-cache
— The browser looks for a matching request in its HTTP cache. only-if-cached
— The browser looks for a matching request in its HTTP cache. "only-if-cached"
mode can only be used if the request's mode
is "same-origin"
. Cached redirects will be followed if the request's redirect
property is "follow"
and the redirects do not violate the "same-origin"
mode.// Download a resource with cache busting, to bypass the cache // completely. fetch("some.json", {cache: "no-store"}) .then(function(response) { /* consume the response */ }); // Download a resource with cache busting, but update the HTTP // cache with the downloaded resource. fetch("some.json", {cache: "reload"}) .then(function(response) { /* consume the response */ }); // Download a resource with cache busting when dealing with a // properly configured server that will send the correct ETag // and Date headers and properly handle If-Modified-Since and // If-None-Match request headers, therefore we can rely on the // validation to guarantee a fresh response. fetch("some.json", {cache: "no-cache"}) .then(function(response) { /* consume the response */ }); // Download a resource with economics in mind! Prefer a cached // albeit stale response to conserve as much bandwidth as possible. fetch("some.json", {cache: "force-cache"}) .then(function(response) { /* consume the response */ });
Specification | Status | Comment |
---|---|---|
Fetch The definition of 'cache' in that specification. | Living Standard | Initial definition |
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | No support | (Yes) | 48 (48) | No support | No support | No support |
only-if-cached | No support | ? | 50 (50) | No support | No support | No support |
Feature | Android | Edge | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|---|
Basic support | No support | (Yes) | No support | No support | No support | No support | No support | No support |
only-if-cached | No support | ? | No support | No support | No support | No support | No support | No support |
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Request/cache