ReadableStream: pipeTo() method
The pipeTo()
method of the ReadableStream
interface pipes the current ReadableStream
to a given WritableStream
and returns a Promise
that fulfills when the piping process completes successfully, or rejects if any errors were encountered.
Piping a stream will generally lock it for the duration of the pipe, preventing other readers from locking it.
Syntax
js
pipeTo(destination)
pipeTo(destination, options)
Parameters
destination
-
A
WritableStream
that acts as the final destination for theReadableStream
. options
Optional-
The options that should be used when piping to the
writable
stream. Available options are:preventClose
-
If this is set to
true
, the sourceReadableStream
closing will no longer cause the destinationWritableStream
to be closed. The method will return a fulfilled promise once this process completes, unless an error is encountered while closing the destination in which case it will be rejected with that error. preventAbort
-
If this is set to
true
, errors in the sourceReadableStream
will no longer abort the destinationWritableStream
. The method will return a promise rejected with the source's error, or with any error that occurs during aborting the destination. preventCancel
-
If this is set to
true
, errors in the destinationWritableStream
will no longer cancel the sourceReadableStream
. In this case the method will return a promise rejected with the source's error, or with any error that occurs during canceling the source. In addition, if the destination writable stream starts out closed or closing, the source readable stream will no longer be canceled. In this case the method will return a promise rejected with an error indicating piping to a closed stream failed, or with any error that occurs during canceling the source. signal
-
If set to an
AbortSignal
object, ongoing pipe operations can then be aborted via the correspondingAbortController
.
Return value
A Promise
that resolves when the piping process has completed.
Exceptions
TypeError
-
The
writableStream
and/orreadableStream
objects are not a writable stream/readable stream, or one or both of the streams are locked.
Examples
js
// Fetch the original image
fetch("png-logo.png")
// Retrieve its body as ReadableStream
.then((response) => response.body)
.then((body) => body.pipeThrough(new PNGTransformStream()))
.then((rs) => rs.pipeTo(new FinalDestinationStream()));
The same example, but using await
:
js
(async () => {
// Fetch the original image
const response = await fetch("png-logo.png");
// Retrieve its body as ReadableStream
response.body
.pipeThrough(new PNGTransformStream())
.pipeTo(new FinalDestinationStream());
})();
Specifications
Specification |
---|
Streams Standard # ref-for-rs-pipe-to④ |
Browser compatibility
BCD tables only load in the browser
See also
ReadableStream()
constructor- Pipe chains