How to get previous value in signals?

[ganjarsetia]

When I'm using useState hooks I can get previous state, like this code below

const [object, setObject] = useState({
  firstKey: '',
  secondKey: '',
});

setObject((prevState) => ({
  ...prevState,
  secondKey: 'value',
}));

Ho to do like this using signals?

[rschristian]

It's just normal JS, no need to do anything special:

const myObject = signal({
    firstKey: '',
    secondKey: '',
});

myObject.value = { ...myObject.value, secondKey: 'value' };

[ganjarsetia]

Thank you!

I was thinking Preact signals has its own way of getting previous value like in SolidJS Signal:

const [route, setRoute] = createSignal(1);

createEffect((prev) => {
  const updated = route();

  console.log('route previous value is', prev);
  console.log('route updated value is', updated);

  return updated;
}, route());

turn out It's just normal JS

[hopemanryan]

When I'm using useState hooks I can get previous state, like this code below

const [object, setObject] = useState({

  firstKey: '',

  secondKey: '',

});



setObject((prevState) => ({

  ...prevState,

  secondKey: 'value',

}));

Ho to do like this using signals?

So I actually started a fork with pr to add a history array for previous values.
It quickly became a need for me