Streaming support

[atgillette]

Is there any plans to add support for streaming, something like what request has?

[dgraham]

There are no current plans for streaming requests or responses. We are limited by what XMLHttpRequest supports.

There is a draft specification for streams in the Fetch API, with a native implementation shipping in Chrome already.

[jimmywarting]

Please reopen, there are two was you can get a stream from XMLHttpRequest.

xhrRequest.responseType = "ms-stream";
// or
xhrRequest.responseType = "moz-chunked-arraybuffer";

If this would be implemented then i would rather want to use the polyfill then firefox or edge partially supported fetch api
This is crucial for my application where i need to handle large file with lower memory.
And with web-stream-polyfill this would be a breeze

[mislav]

Sure, let's revisit this. But I make no promises about actually implementing this in github/fetch.

It sounds like we can get native streaming from Chrome 43+, and streaming via XHR in IE and Firefox. How about Safari— is anything available there?

[jimmywarting]

Like i said to jonnyreeves/chunked-request

Played a bit myself with streams and monkey patching xhr:
This is how i would do it for firefox: https://jsfiddle.net/98L105v3/2/

I created it yesterday, maybe it would be of any interest?

[jimmywarting]

Borrow some info from jonnyreeves/chunked-request#16

• Chrome: use native reader from fetch
• FF: set responseType to moz-chunked-arraybuffer, get ArrayBuffer(s) from xhr.response progress event(s), accumulate if needed, resolve reader.read Promise
• IE10+: set responseType to ms-stream, call readAsArrayBuffer on xhr.response to get an eventemitter, get ArrayBuffer(s) from eventemitter progress event(s), accumulate if needed, resolve reader.read Promise
• IE9: set responseType to text, slice xhr.responseText on progress event(s) to get chunk(s), convert to ArrayBuffer(s) using text-encoding-utf-8, accumulate if needed, resolve reader.read Promise
• Safari: until it supports fetch, basically do the same thing as for IE9, except use native Uint8Array when converting to ArrayBuffer like this.

They also utility a partial request method (making multiple range request) Perhaps this would be a solution or just make it overkill

[jimmywarting]

if this gets implemented the we can't use this code any longer

  if (self.fetch) {
    return
  }

Cuz with streams i think the polyfill would actually be better then the partial fetch api FF & Edge supports

[jimmywarting]

Oh, and by the way.
If someone would do new Responsen(blob, {}).body.getReader() then there is some code you can take out of my Screw-FileReader lib about the part where I make a blob to a ReadableStream 😉

[caub]

Even if XMLHttpRequest can't really do streams, I think it would be great to have https://github.com/domenic/streams-demo working on old browsers, with only one chunk, and by adding a res.body.getReader()