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Quick example of using fetch to parse a chunked response
var chunkedUrl = 'https://jigsaw.w3.org/HTTP/ChunkedScript';
fetch(chunkedUrl)
.then(processChunkedResponse)
.then(onChunkedResponseComplete)
.catch(onChunkedResponseError)
;
function onChunkedResponseComplete(result) {
console.log('all done!', result)
}
function onChunkedResponseError(err) {
console.error(err)
}
function processChunkedResponse(response) {
var text = '';
var reader = response.body.getReader()
var decoder = new TextDecoder();
return readChunk();
function readChunk() {
return reader.read().then(appendChunks);
}
function appendChunks(result) {
var chunk = decoder.decode(result.value || new Uint8Array, {stream: !result.done});
console.log('got chunk of', chunk.length, 'bytes')
text += chunk;
console.log('text so far is', text.length, 'bytes\n');
if (result.done) {
console.log('returning')
return text;
} else {
console.log('recursing')
return readChunk();
}
}
}
got chunk of 32768 bytes
text so far is 32768 bytes
recursing
got chunk of 32768 bytes
text so far is 65536 bytes
recursing
got chunk of 6664 bytes
text so far is 72200 bytes
recursing
got chunk of 0 bytes
text so far is 72200 bytes
returning
all done! This output will be chunked encoded by the server, if your client is HTTP/1.1
<snip>
@jamesward

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@jamesward jamesward commented Feb 14, 2018

FYI, this doesn't seem to work on Firefox.

@supamanda

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@supamanda supamanda commented Sep 28, 2018

According to https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API :

[The Streaming response body] feature is behind the dom.streams.enabled preference and the javascript.options.streams preference. To change preferences in Firefox, visit about:config.

Firefox disables those 2 options by default & they need to be enabled for this to work.

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