Feature: Streaming responses

[peterjosling]

The XHR emits progress events as per the spec, but doesn't populate the response/responseText properties until the request has completed, so it's impossible to utilise streaming requests (for things such as Twitter's streaming API).

[jpillora]

Very true, response/text is not set per progress.

As an aside, I briefly tested Twitter's API with XMLHttpRequest and it wasn't very fun, had to pull the current text and diff it with what I had already processed. This would get slower and slower the longer you stream. Have you also encountered this?

[peterjosling]

Previously I've just stored the length of the response body from the previous progress event and then pulled out the substring from that index onwards. Speed's never been an issue - I just put in a check to close and reopen the stream if the response grew over a few MB in size (as you can't clear it).

[jpillora]

Ah yep, length slicing + reopening the stream seems like a good solution. This shouldn't be too hard to add, will look into it tonight

[mscdex]

+1 This is what Yaffle/EventSource does and it would be great to have these two polyfills work together better.