ReadableStream.pipeTo()

Draft
This page is not complete.

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

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

readableStreamInstance.pipeTo(destination, options);

Parameters

destination
A WritableStream that acts as the final destination for the ReadableStream.
options Optional
An options object containing properties that can define when cancellation, closing, or aborting of the stream is prevented (all optional). The options are:
  1. preventClose: If this is set to true, the source ReadableStream closing will no longer cause the destination WritableStream 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.
  2. preventAbort: If this is set to true, errors in the source ReadableStream will no longer abort the destination WritableStream. The method will return a promise rejected with the source’s error, or with any error that occurs during aborting the destination.
  3. preventCancel: If this is set to true, errors in the destination WritableStream will no longer cancel the source ReadableStream. 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.

Return value

Void.

Exceptions

TypeError
The writableStream and/or readableStream objects are not a writable stream/readable stream, or one or both of the streams are locked.

Examples

// 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()))

Specifications

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

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support59 ?571 No46 ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support5959 ?57146 ? ?

1. From version 57: this feature is behind the dom.streams.enabled preference (needs to be set to true) and the javascript.options.streams preference (needs to be set to true). To change preferences in Firefox, visit about:config.

Document Tags and Contributors

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