Reactive utilities

on

Solid 2.0 —

The on helper has been removed in Solid 2.0. The split effect model makes it unnecessary — the compute function already serves as the explicit dependency declaration.

Replacement: split effects

The on helper was designed to make effect dependencies explicit. In Solid 2.0, the split effect model achieves this naturally:

// 1.x — using on() for explicit dependencies
import { on, createEffect } from "solid-js"

createEffect(on(a, (v) => console.log(v, b())))

// 2.0 — compute function declares dependencies, apply runs the side effect
createEffect(
  () => a(),               // compute: explicitly track only `a`
  (v) => console.log(v, b()) // apply: `b` is not tracked
)

Deferred execution

The defer option that prevented the first run is no longer needed — effects in Solid 2.0 are already deferred by default (scheduled after the rendering phase).

Multiple dependencies

// 1.x
createEffect(on([a, b], ([aVal, bVal]) => console.log(aVal, bVal)))

// 2.0
createEffect(
  () => [a(), b()],
  ([aVal, bVal]) => console.log(aVal, bVal)
)

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