badbatchcacheability
A utility class to parse, store and print http cache headers.
Installation
npm add cacheabilityDocumentation
Initialization
The constructor takes either a Headers instance, object literal of header key/values, cache-control header field value or Cacheability metadata object, parses it, if required, and then stores the result on the Cacheability instance's metadata property.
import { Cacheability } from "cacheability";
const headers = new Headers({
"cache-control": "public, max-age=60",
"content-type": "application/json",
"etag": "33a64df551425fcc55e4d42a148795d9f25f89d4",
});
const cacheability = new Cacheability({ headers });
const { cacheControl, etag, ttl } = cacheability.metadata;
// cacheControl is { maxAge: 60, public: true }
// etag is 33a64df551425fcc55e4d42a148795d9f25f89d4
// ttl is 1516060712991 if Date.now is 1516060501948Properties
metadata
The property holds the Cacheability instance's parsed cache headers data, including cache control directives, etag, and a derived TTL timestamp.
Methods
checkTTL
The method checks whether the TTL timestamp stored in the Cacheability instance is still valid, by comparing it to the current timestamp.
const cacheability = new Cacheability({ cacheControl: "public, max-age=3" });
// One second elapses...
const isValid = cacheability.checkTTL();
// isValid is true
// Three seconds elapse...
const isStillValid = cacheability.checkTTL();
// isStillValid is falseprintCacheControl
The method prints a cache-control header field value based on the Cacheability instance's metadata. The max-age and/or s-maxage are derived from the TTL stored in the metadata.
const cacheability = new Cacheability({ cacheControl: "public, max-age=60, s-maxage=60" });
// Five seconds elapse...
const cacheControl = cacheability.printCacheControl();
// cacheControl is "public, max-age=55, s-maxage=55"Changelog
Check out the features, fixes and more that go into each major, minor and patch version.
License
Cacheability is MIT Licensed.