"Pushing" updates to the website?

[philippludwig]

So after working through the tutorial, I wonder if it is possible to display the status of a long-running task on the web page. Toy example: Let's say I have a counter (def +counter+ (atom 1)) that gets increased once per second from a different thread.

Is it possible to show the current value of +counter+ without manually refreshing the page?

I am aware that there is a section in the tutorial about websockets, but I did not understand the majority of it. Maybe someone has already done something like this and can provide a simple example?

[philippludwig]

This is in fact described in the htmx manual: https://hypermedia.systems/a-dynamic-archive-ui/

tl;dr: You use conditional polling.

[jacobobryant]

polling is a simple, fine way to do this. if that works for your use case it'll probably be the easiest way to do it. websockets as implemented in the tutorial app also work if you e.g. needed more immediate updates or something. If you did want to dig into how the websocket stuff works I'd be happy to clarify anything that's confusing. From a high level, the idea is:

1. htmx opens a websocket connection. On the backend when this happens, we store a connection object in memory somewhere (inside the system map).
2. other parts of your backend code can then access the websocket connection via the system map and send messages over it when needed.