This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The ReadableStream
interface of the Streams API represents a readable stream of byte data. The Fetch API offers a concrete instance of a ReadableStream
through the body
property of a Response
object.
ReadableStream()
ReadableStream.locked
Read only
locked
getter returns whether or not the readable stream is locked to a reader.ReadableStream.cancel()
ReadableStream.getReader()
ReadableStream.pipeThrough()
ReadableStream.pipeTo()
WritableStream
and returns a promise that fulfills when the piping process completes successfully, or rejects if any errors were encountered.ReadableStream.tee()
tee
method tees this readable stream, returning a two-element array containing the two resulting branches as new ReadableStream
instances.In the following example, an artifical Response
is created to stream HTML fragments fetched from another resource to the browser.
It demonstrates the usage of a ReadableStream
in combination with a Uint8Array
.
fetch("https://www.example.org/").then((response) => { const reader = response.body.getReader(); const stream = new ReadableStream({ start(controller) { // The following function handles each data chunk function push() { // "done" is a Boolean and value a "Uint8Array" return reader.read().then(({ done, value }) => { // Is there no more data to read? if (done) { // Tell the browser that we have finished sending data controller.close(); return; } // Get the data and send it to the browser via the controller controller.enqueue(value); }).then(push); }; push(); } }); return new Response(stream, { headers: { "Content-Type": "text/html" } }); });
Specification | Status | Comment |
---|---|---|
Streams The definition of 'ReadableStream' in that specification. | Living Standard | Initial definition |
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 43.0 | No support[1] | ? | 39 | ? |
pipeThrough and pipeTo methods | 59.0 | No support[1] | ? | 46 | ? |
Feature | Android Webview | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | 43 | 43 | No support[1] | ? | 39 | ? |
pipeThrough and pipeTo methods | 59 | 59 | No support[1] | ? | 46 | ? |
[1] Readable streams are currently enabled in Firefox, but hidden behind the dom.streams.enabled
and javascript.options.streams
prefs.
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream