docs/recipes/atom-with-toggle.mdx
atomWithTogglecreates 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>
</>
)
}