Response.arrayBuffer()
The arrayBuffer()
method of the Response
interface
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.
Return value
A promise that resolves with an ArrayBuffer
.
Examples
Playing music
In our fetch array
buffer live, we have a Play button. When pressed, the getData()
function is run. Note that before playing full audio file will be downloaded. If you
need to play ogg during downloading (stream it) - consider
HTMLAudioElement
:
new Audio("music.ogg").play();
In getData()
we create a new request using the
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) {
return 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');
}
Reading files
The Response()
constructor accepts
File
s and Blob
s, so it may be used to read a
File
into other formats.
function readFile(file) {
return new Response(file).arrayBuffer();
}
<input type="file" onchange="readFile(this.files[0])">
Specifications
Specification |
---|
Fetch Standard # ref-for-dom-body-arraybuffer① |
Browser compatibility
BCD tables only load in the browser