cancel

~ ReadableStreamDefaultReader.cancel()

The cancel() method of the ReadableStreamDefaultReader interface returns a Promise that resolves when the stream is canceled. Calling this method signals a loss of interest in the stream by a consumer.

Cancel is used when you've completely finished with the stream and don't need any more data from it, even if there are chunks enqueued waiting to be read. That data is lost after cancel is called, and the stream is not readable any more. To read those chunks still and not completely get rid of the stream, you'd use ReadableStreamDefaultController.close().

Note: If the reader is active, the cancel() method behaves the same as that for the associated stream (ReadableStream.cancel()).

Syntax

cancel()
cancel(reason)

Parameters

• reason optional
  • : A human-readable reason for the cancellation. This value may or may not be used.

Return value

A Promise, which fulfills with the value given in the reason parameter.

Exceptions

• TypeError
  • : The source object is not a ReadableStreamDefaultReader, or the stream has no owner.