WritableStreamDefaultController

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨May 2022⁩.

Note: This feature is available inWeb Workers.

TheWritableStreamDefaultController interface of theStreams API represents a controller allowing control of aWritableStream's state. When constructing aWritableStream, the underlying sink is given a correspondingWritableStreamDefaultController instance to manipulate.

Constructor

None.WritableStreamDefaultController instances are created automatically duringWritableStream construction.

Instance properties

WritableStreamDefaultController.signalRead only: Returns theAbortSignal associated with the controller.

Instance methods

WritableStreamDefaultController.error(): Causes any future interactions with the associated stream to error.

Examples

const writableStream = new WritableStream({  start(controller) {    // do stuff with controller    // error stream if necessary    controller.error("My stream is broken");  },  write(chunk, controller) {    // …  },  close(controller) {    // …  },  abort(err) {    // …  },});