Body.arrayBuffer()

The arrayBuffer() method of the Body mixin takes a Response stream and reads it to completion. It returns a promise that resolves with an ArrayBuffer.

Syntax

response.arrayBuffer().then(function(buffer) {
  // do something with buffer
)};

Parameters

None.

Returns

A promise that resolves with an ArrayBuffer.

Example

In our fetch array buffer example (run fetch array buffer live), we have a Play button. When pressed, the getData() function is run.

In getData() we create a new request using the Request.Request constructor, then use it to fetch an OGG music track. We also use AudioContext.createBufferSource to create an audio buffer source.  When the fetch is successful, we read an ArrayBuffer out of the response using arrayBuffer(), decode the audio data using AudioContext.decodeAudioData, set the decoded data as the audio buffer source's buffer (source.buffer), then connect the source up to the AudioContext.destination.

Once getData() has finished running, we start the audio source playing with start(0), then disable the play button so it can't be clicked again when it is already playing (this would cause an error.)

function getData() {
  source = audioCtx.createBufferSource();

  var myRequest = new Request('viper.ogg');

  fetch(myRequest).then(function(response) {
    response.arrayBuffer().then(function(buffer) {
      audioCtx.decodeAudioData(buffer, function(decodedData) {
        source.buffer = decodedData;
        source.connect(audioCtx.destination);
      });
    });
  });
};

// wire up buttons to stop and play audio

play.onclick = function() {
  getData();
  source.start(0);
  play.setAttribute('disabled', 'disabled');
}

Specifications

Browser compatibility

[1] In Chrome 42, Firefox 34 and Opera 28 support for arrayBuffer() was hidden behind a preference.

See also

• ServiceWorker API
• HTTP access control (CORS)
• HTTP