https://github.com/badbatch/cacheability
A utility class to parse, store and print http cache headers.
https://github.com/badbatch/cacheability
cache-control cacheability etag headers http parser
Last synced: 10 months ago
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A utility class to parse, store and print http cache headers.
- Host: GitHub
- URL: https://github.com/badbatch/cacheability
- Owner: badbatch
- License: mit
- Created: 2017-09-04T20:47:56.000Z (over 8 years ago)
- Default Branch: main
- Last Pushed: 2024-11-24T22:54:30.000Z (about 1 year ago)
- Last Synced: 2025-04-12T06:04:53.297Z (10 months ago)
- Topics: cache-control, cacheability, etag, headers, http, parser
- Language: TypeScript
- Homepage:
- Size: 1.48 MB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# cacheability
A utility class to parse, store and print http cache headers.
[](https://github.com/badbatch/cacheability/actions/workflows/build-and-publish.yml)
[](LICENSE)
[](https://badge.fury.io/js/cacheability)
## Installation
```bash
npm add cacheability
```
## Documentation
### 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.
```javascript
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 1516060501948
```
### Properties
#### 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.
```javascript
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 false
```
#### printCacheControl
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.
```javascript
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](CHANGELOG.md) that go into each major, minor and patch version.
## License
Cacheability is [MIT Licensed](LICENSE).