ReadableStreamDefaultController.close()

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This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The close() method of the ReadableStreamDefaultController interface closes the associated stream.

Readers will still be able to read any previously-enqueued chunks from the stream, but once those are read, the stream will become closed. If you want to completely get rid of the stream and discard any enqueued chunks, you'd use ReadableStream.cancel() or ReadableStreamDefaultReader.cancel().

Syntax

readableStreamDefaultControllerInstance.close();

Parameters

None.

Return value

Void.

Exceptions

TypeError
The source object is not a ReadableStreamDefaultController.

Examples

In the following simple example, a custom ReadableStream is created using a constructor (see our Simple random stream example for the full code). The start() function generates a random string of text every second and enqueues it into the stream. A cancel() function is also provided to stop the generation if ReadableStream.cancel() is called for any reason.

When a button is pressed, the generation is stopped, the stream is closed using ReadableStreamDefaultController.close(), and another function is run, which reads the data back out of the stream.

const stream = new ReadableStream({
  start(controller) {
    interval = setInterval(() => {
      let string = randomChars();

      // Add the string to the stream
      controller.enqueue(string);

      // show it on the screen
      let listItem = document.createElement('li');
      listItem.textContent = string;
      list1.appendChild(listItem);
    }, 1000);

    button.addEventListener('click', function() {
      clearInterval(interval);
      fetchStream();
      controller.close();
    })
  },
  pull(controller) {
    // We don't really need a pull in this example
  },
  cancel() {
    // This is called if the reader cancels,
    // so we should stop generating strings
    clearInterval(interval);
  }
});

Specifications

Specification Status Comment
Streams
The definition of 'close()' in that specification.
Living Standard Initial definition.

Browser compatibility

No compatibility data found. Please contribute data for "path.to.feature.NameOfTheProperty" (depth: 1) to the MDN compatibility data repository.

Document Tags and Contributors

 Contributors to this page: chrisdavidmills
 Last updated by: chrisdavidmills,