WEB.17.02 Mid-level

Streaming, progress and beacons

Comes up in: Web fundamentals

This concept is being written. It gets the full five steps — explanation, predict, interview angle, practice with tests, and review cards. Here is exactly what it will cover, so you can study it elsewhere in the meantime.

What it covers

reading response.body as a stream
download progress
upload progress (XHR still needed in many browsers — check fact)
navigator.sendBeacon and fetch keepalive for analytics on page hide
visibilitychange over unload

Words you will know

readable streambeacon

What you will practise

download progress bar

Interview questions this answers

How do you show download progress with fetch?
How do you reliably send analytics when the user leaves the page?