atomWithToggle

atomWithToggle creates a new atom with a boolean as initial state & a setter function to toggle it.

This avoids the boilerplate of having to set up another atom just to update the state of the first.

import { WritableAtom, atom } from 'jotai'

export function atomWithToggle(
  initialValue?: boolean,
): WritableAtom<boolean, [boolean?], void> {
  const anAtom = atom(initialValue, (get, set, nextValue?: boolean) => {
    const update = nextValue ?? !get(anAtom)
    set(anAtom, update)
  })

  return anAtom as WritableAtom<boolean, [boolean?], void>
}

An optional initial state can be provided as the first argument.

The setter function can have an optional argument to force a particular state, such as if you want to make a setActive function out of it.

Here is how it’s used.

import { atomWithToggle } from 'XXX'

// will have an initial value set to true
const isActiveAtom = atomWithToggle(true)

And in a component:

const Toggle = () => {
  const [isActive, toggle] = useAtom(isActiveAtom)

  return (
    <>
      <button onClick={() => toggle()}>
        isActive: {isActive ? 'yes' : 'no'}
      </button>
      <button onClick={() => toggle(true)}>force true</button>
      <button onClick={() => toggle(false)}>force false</button>
    </>
  )
}