ReadableStream : Object

constructor

Represents a readable stream of data. The stream can be read using the ReadableStreamReader or by piping to a WritableStream.

Spec

Constructors

new ReadableStream(source : ReadableStreamSource, [strategy : QueuingStrategy]) : ReadableStream

Spec

Instance Properties

locked : Boolean readonly

Spec

Instance Methods

cancel([reason : Object]) : Promise<undefined>

Spec

getReader([options : Object]) : ReadableStreamDefaultReader

options : {

mode : String Either undefined or 'byob'

}

Example:

const res = await fetch('/fireworks.ogv');
const reader = res.body.getReader();

let result;
while (!(result = await reader.read()).done) {
  console.log('chunk size:', result.value.byteLength);
}

Run

Results:

Spec

pipeThrough(transform : Object, [options : Object]) : ReadableStream

transform : {

readable :	ReadableStream
writable :	WritableStream

}

options : {

signal :	AbortSignal
preventAbort :	Boolean
preventCancel :	Boolean
preventClose :	Boolean

}

Allows transforming the stream of data. Each chunk is passed to transform.writable. Returns transform.readable. See TransformStream for a convienient way to make the transform parameter.

Example:

const reader = new ReadableStream({
  start(controller) {
    ['a', 'b', 'c'].forEach(s => controller.enqueue(s));
    controller.close();
  }
}).pipeThrough(new TransformStream({
  transform(chunk, controller) {
    controller.enqueue(chunk.toUpperCase());
  }
})).getReader();

let result;
while (!(result = await reader.read()).done) {
  console.log(result.value);
}

Run

Results:

Spec

pipeTo(destination : WritableStream, [options : Object]) : Promise<undefined>

options : {

signal :	AbortSignal
preventAbort :	Boolean
preventCancel :	Boolean
preventClose :	Boolean

}

Passes each chunk to the WritableStream.

Example:

const res = await fetch('/fireworks.ogv');
res.body.pipeTo(new WritableStream({
  write(chunk) {
    console.log('chunk size:', chunk.byteLength);
  }
}));

Run

Results:

Spec

tee() : Array<ReadableStream>

Spec

home license contribute feedback toggle light/dark mode