When developing React applications, it’s common to encounter scenarios where you need to implement an undo functionality, allowing users to revert changes they’ve made. Immer is a powerful library that simplifies state management by enabling you to work with immutable data structures without the complexity of manual cloning.

In this blog post, we will walk through the process of implementing undo functionality in a React application using Immer.

Getting started

Before we dive into the implementation details, let’s set up a basic React application using Create React App.

npx create-react-app undo-demo
cd undo-demo
npm start

Installing Immer

To use Immer in our project, we need to install it first. Open a new terminal window and run the following command:

npm install immer

Implementing undo functionality

Let’s assume we have a simple component that renders a text input element and a button. The user can edit the input field and click the button to save the changes. Our goal is to allow the user to undo their changes by clicking on another button.

import React, { useState } from "react";
import produce from "immer";

const UndoComponent = () => {
  const [text, setText] = useState("");
  const [history, setHistory] = useState([]);

  const handleInputChange = (event) => {
    setText(event.target.value);
  };

  const handleSave = () => {
    setHistory(produce(history, (draft) => {
      draft.push(text);
    }));
  };

  const handleUndo = () => {
    if (history.length > 0) {
      setHistory(produce(history, (draft) => {
        draft.pop();
      }));
    }
  };

  return (
    <div>
      <input type="text" value={text} onChange={handleInputChange} />
      <button onClick={handleSave}>Save</button>
      <button onClick={handleUndo}>Undo</button>
    </div>
  );
};

export default UndoComponent;

In the above code, we introduced a new state variable history which keeps track of the previous versions of the text state. We use produce from Immer to create an immutable copy of history when updating it. The handleSave function is responsible for adding the current text value to the history array. Similarly, the handleUndo function removes the last item from the history array if it’s not empty.

Conclusion

By utilizing Immer, we were able to implement undo functionality in our React application in a more concise and efficient manner. Immer’s ability to work with immutable data greatly simplifies state management, reducing the chances of introducing bugs caused by manual state cloning.

Implementing undo functionality with Immer in React applications allows users to have a seamless experience by easily reverting changes they’ve made. Give it a try in your next project, and see how Immer simplifies your state management code.

#React #UndoFunctionality #Immer