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()
.
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.
let interval;
const stream = new ReadableStream({
start(controller) {
interval = setInterval(() => {
let string = randomChars();
controller.enqueue(string);
let listItem = document.createElement("li");
listItem.textContent = string;
list1.appendChild(listItem);
}, 1000);
button.addEventListener("click", () => {
clearInterval(interval);
fetchStream();
controller.close();
});
},
pull(controller) {
},
cancel() {
clearInterval(interval);
},
});