ReadableStreamBYOBReader: cancel() method
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Note: This feature is available in Web Workers.
The cancel() method of the ReadableStreamBYOBReader 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.
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
reasonOptional-
A human-readable reason for the cancellation. The underlying source may or may not use it.
Return value
A Promise, which fulfills with the value given in the reason parameter.
Exceptions
TypeError-
The source object is not a
ReadableStreamBYOBReader, or the stream has no owner.
Examples
This example code calls the cancel() method when a button is pressed, passing the string "user choice" as a reason. The promise resolves when cancellation completes.
button.addEventListener("click", () => { reader.cancel("user choice").then(() => console.log(`cancel complete`)); }); Note that this code can be seen running in the Using readable byte streams example code (press the Cancel stream button).
Specifications
| Specification |
|---|
| Streams # ref-for-generic-reader-cancel② |
Browser compatibility
See also
ReadableStreamBYOBReader()constructor- Using readable byte stream