CacheControlDirective

CacheControlDirective describes a Cache-Control header as a plain object and serializes it to the header string. It is used by StaticRoute and BundleRoute for their cache options, and can be used directly on any Headers instance.

The class doubles as the type: plain object literals satisfy it, so instantiation with new is never required. Anywhere a CacheControlDirective is expected, { public: true, maxAge: 3600 } works as-is.

Usage
Fields
Static Methods

Usage

As a plain object

import { C } from "@ozanarslan/corpus";

// hashed assets, cache forever
new C.StaticRoute("/logo", {
	filePath: addr("assets", "logo-3f2a1b.svg"),
	cache: { public: true, maxAge: 31536000, immutable: true },
});

// always revalidate
new C.StaticRoute("/manifest", {
	filePath: addr("assets", "manifest.json"),
	cache: { noCache: true },
});

Serializing manually

CacheControlDirective.createHeaderString({ public: true, maxAge: 3600 });
// "public, max-age=3600"

CacheControlDirective.createHeaderString({ public: true, maxAge: 31536000, immutable: true });
// "public, max-age=31536000, immutable"

CacheControlDirective.createHeaderString({ noStore: true, maxAge: 3600 });
// "no-store" (everything else is ignored)

Applying to a Headers instance

CacheControlDirective.applyHeader(c.res.headers, { public: true, maxAge: 3600 });

Fields

All fields are optional.

Field	Type	Serialized as	Description
`noStore`	`boolean`	`no-store`	Response must not be stored at all. Overrides everything else.
`noCache`	`boolean`	`no-cache`	Response must be revalidated before use. Overrides everything below.
`public`	`boolean`	`public`	Response may be stored by shared caches.
`maxAge`	`number`	`max-age={n}`	Freshness lifetime in seconds.
`immutable`	`boolean`	`immutable`	Response will never change while fresh; skips revalidation.

Precedence

Serialization short-circuits in this order:

noStore: true produces "no-store" and ignores all other fields.
noCache: true produces "no-cache" and ignores all other fields.
Otherwise public, maxAge, and immutable are joined with ", " in that order.

An object with no set fields serializes to an empty string.

Static Methods

createHeaderString

createHeaderString(opts: CacheControlDirective): string

Serializes the directive to a Cache-Control header value following the precedence rules.

applyHeader

applyHeader(headers: Headers, opts: CacheControlDirective): Headers

Serializes the directive and sets it as the Cache-Control header on the given Headers instance. Returns the same instance.