In Redux, you can implement undo and redo functionality by storing past states in an array.
Here is a basic idea of how it works with Redux:
1. Initial setup: Begin by setting up a Redux store as usual. Create your action types, action creators and reducer.
1. Implementing Undo/Redo: The idea behind undo/redo in Redux is to store past and future states in your Redux store. These states can be stored in two arrays – one for past states and one for future states. The state for your app is always the last item in the “past” array.
1. Action: When an action is dispatched and it changes the state, you store the previous state into the “past” array.
1. Undo: When you want to perform an undo, you pop the last state from the “past” array and push it to the “future” array and set the current state to the next last item in the “past” array.
1. Redo: When you want to redo, you take the state from the “future” array and set it as the current state and also push it back to the “past” array.
Redux library also has a handy package redux-undo which can easily add this functionality to your app.
This functionality in Redux should be used very carefully because storing every action and the resulting state can be memory intensive, especially for large applications. It is advisable to implement this only where explicitly needed.
