ws connection keeps "loading..."

[hpvd]

just found it several times that ws connections keeps "loading..." (no connection is established)
when click on the menu items (other sites) there is an error report in devtools

[beenotung]

I can get the ws connected on the demo site right now but I can recall I experienced similar issue before.

It could be due to the proxy in-front of the demo server was restarting.

When the ws connection was not established, do you see full page load when switching page from menu, or is it stuck on the previous page?

[hpvd]

Thanks for looking in this. Working for me too now. Even now, there is a pretty notable variation in ws connection times.
When ws was not established yesterday, there were full page loads when clicking through menu.

[hpvd]

just make it broken :-)
maybe it has something to do with load. Yesterday had the feeling that it happens when you click fast through the menu.
Today it happens when using the thermostat demo and rising desired temperature level with 10+ fast clicks...

[hpvd]

seems like I found a (special) way to reproduce it:
use thermostat demo, rise desired temperature and reload page before this temperature is reached
In this case ws seems to be unavailable.

Another finding, after procedure above:
when going back to home, a ws connection is established.
Going to thermostat page again, temperatures are default.
As soon as you one time click the plus symbol, the temperatures jump to the values from the page visit before.
Looks like something is restored to the values of the visit before.
If so, this shouldn't happen at all, or it should happen directly when opening this page (and not only after the first action).

[beenotung]

If you see the temperature is reset, it indicates the demo server was restarted because it's kept in-memory, not persisted across restart.

It seems you found a way to crash the server, I'll look into this pattern.

[beenotung]

seems like I found a (special) way to reproduce it: use thermostat demo, rise desired temperature and reload page before this temperature is reached In this case ws seems to be unavailable.

This was probably because the server tried to send websocket message to a (just) closed connection, then crashed.

This should be fixable if we check the socket state before sending messages, will add the checking to see if it can fix it.

Another finding, after procedure above: when going back to home, a ws connection is established. Going to thermostat page again, temperatures are default. As soon as you one time click the plus symbol, the temperatures jump to the values from the page visit before. Looks like something is restored to the values of the visit before. If so, this shouldn't happen at all, or it should happen directly when opening this page (and not only after the first action).

This was because the thermostat page was completely pre-rendered at boot time. I've changed the temperature fraction to be re-evaluated at request time. The rest of page is still pre-rendered only once.

You can see how we express a fraction to be re-evaluated using inline functional component in this commit: a7148a4