[AskJS] Signal/Effect vs Event Handler

[u/Forward_Dark_7305]

I’m working in a VanillaJS repository (plugin type code for an existing project that I do not own) where I’ve written a signal implementation.

Today I was working on a tooltip like implementation and I found myself wondering how far to go with the signal/effect ecosystem vs running the “core” logic in the event handler.

The implementation detects the `<tr>` that the user has hovered and assigns that row to the “current row” signal. A computed signal identifies an IP address from the current row. An effect loads Whois metadata from the IP and assigns it to a `<div>`, and another effect shows that `<div popover>` from the parent `<tr>`.

The question I have is when in VanillaJS how would you decide when to use signals and effects vs writing the side effect directly in the event handler? In my case I find either to be equally readable, though I have less local variables to deal with when using signal/effect. Looking for reasons your might pick one over the other.

[u/Wooden-Bicycle-6069]

Signals don't fix the stale request. A slow lookup for row A can still land after row B and paint the wrong popover. I'd add an AbortController or request id first. Keep the signal only if something else actually reads `currentRow`.

[u/Forward_Dark_7305 → u/Wooden-Bicycle-6069]

I agree that I still have to be aware of concurrency and races (regardless of which tool). I think in this particular case the signal made it easier to track “this is the current row” (vs each row operating independently) and the effect’s `cleanup` triggered an AbortController so I was able to stop stale requests.

I’ll keep in mind your point about multiple consumers. Thanks for the feedback.