index.md

title	WritableStreamDefaultController
slug	Web/API/WritableStreamDefaultController
page-type	web-api-interface
browser-compat	api.WritableStreamDefaultController

{{APIRef("Streams")}}{{AvailableInWorkers}}

The WritableStreamDefaultController interface of the Streams API represents a controller allowing control of a {{domxref("WritableStream")}}'s state. When constructing a WritableStream, the underlying sink is given a corresponding WritableStreamDefaultController instance to manipulate.

Constructor

None. WritableStreamDefaultController instances are created automatically during WritableStream construction.

Instance properties

• {{domxref("WritableStreamDefaultController.signal")}} {{ReadOnlyInline}}
  • : Returns the {{domxref("AbortSignal")}} associated with the controller.

Instance methods

• {{domxref("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) {
    // …
  },
});

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}