Undo-redo functionality is a common requirement in many applications, allowing users to reverse and restore their actions. In this blog post, we will walk through the process of creating a custom useUndoRedo hook in React to easily implement undo-redo functionality in our application.

Table of Contents

• Introduction
• Prerequisites
• Implementing the useUndoRedo Hook
• Using the useUndoRedo Hook
• Conclusion

Introduction

Undo-redo functionality can be a powerful addition to any application, allowing users to undo their last action or redo a previously undone action. By creating a custom useUndoRedo hook, we can encapsulate the logic and state management required for implementing this feature.

Prerequisites

To follow along with this tutorial, you need to have a basic understanding of React hooks and functional components.

Implementing the useUndoRedo Hook

Here’s an example implementation of the useUndoRedo hook:

import React, { useState } from 'react';

const useUndoRedo = (initialState) => {
  const [currentState, setCurrentState] = useState(initialState);
  const [pastStates, setPastStates] = useState([]);
  const [futureStates, setFutureStates] = useState([]);

  const undo = () => {
    if (pastStates.length === 0) return;

    const previousState = pastStates[pastStates.length - 1];
    const newPastStates = pastStates.slice(0, pastStates.length - 1);
    const newFutureStates = [...futureStates, currentState];

    setCurrentState(previousState);
    setPastStates(newPastStates);
    setFutureStates(newFutureStates);
  };

  const redo = () => {
    if (futureStates.length === 0) return;

    const nextState = futureStates[futureStates.length - 1];
    const newFutureStates = futureStates.slice(0, futureStates.length - 1);
    const newPastStates = [...pastStates, currentState];

    setCurrentState(nextState);
    setPastStates(newPastStates);
    setFutureStates(newFutureStates);
  };

  const updateState = (newState) => {
    setPastStates([...pastStates, currentState]);
    setCurrentState(newState);
    setFutureStates([]);
  };

  return [currentState, updateState, undo, redo];
};

export default useUndoRedo;

In the above code, we define a custom hook called useUndoRedo. It takes an initialState parameter and returns an array with the current state, an updateState function to set the current state, an undo function to revert to the previous state, and a redo function to redo an undone action.

The hook utilizes the useState hook to manage the current, past, and future states. The undo and redo functions update the states accordingly.

Using the useUndoRedo Hook

To use the useUndoRedo hook in your React component, first import it:

import useUndoRedo from './useUndoRedo';

Then, in your functional component, call the hook and destructure the returned values:

const MyComponent = () => {
  const [currentState, updateState, undo, redo] = useUndoRedo('Initial state');

  // Rest of your component code

  return (
    // JSX code
  );
};

You can then use currentState to access the current state, updateState to update the state, and undo and redo to handle the undo and redo functionality.

Conclusion

In this tutorial, we learned how to create a custom useUndoRedo hook in React for implementing undo-redo functionality. By encapsulating the logic and state management within the hook, we can easily incorporate this feature into our applications. Remember to handle the states and functions returned by the hook to enable undo and redo actions in your components.

Give it a try and enhance the user experience of your applications by adding undo-redo functionality using custom hooks.

#react #hooks