Efficient State Management in React: Preserving Values Without Rerenders using useRef

In React, managing state efficiently is crucial for building high-performance applications. While React’s built-in state management hooks like useState and useReducer provide convenient ways to manage component state, they can trigger unnecessary re-renders when state values are updated. In certain scenarios, we may want to preserve values without causing re-renders, especially when dealing with form values or other data that doesn’t affect the UI.

One approach to achieve this is by using React’s useRef hook. Unlike useState or

useReducer

, useRef creates a mutable reference that persists across re-renders, allowing us to store values without triggering re-renders when they change.

Why Avoid Rerenders?

Rerenders in React occur when the state of a component changes, leading to the reconciliation process where the virtual DOM is updated and the component re-renders. While React’s reconciliation algorithm is optimized for performance, unnecessary rerenders can impact the user experience, especially in complex applications with large component trees.

Using useRef for Value Preservation

The useRef hook is primarily used to create mutable references to DOM elements, but it can also be used to store other types of values, such as form values or any data that needs to be preserved without causing rerenders.

Here’s a basic example of how to use useRef to preserve values without triggering rerenders:

import { useRef } from 'react';
function MyComponent() {
  const formValuesRef = useRef({});
  const handleChange = (e) => {
    const { name, value } = e.target;
    formValuesRef.current[name] = value;
  };
  return (
<div>
      <input type="text" name="username" onChange={handleChange} />
      <input type="password" name="password" onChange={handleChange} />
    </div>
  );
}

In this example:

• We create a formValuesRef using useRef to store form values.
• Inside the handleChange function, we update the formValuesRef.current object with the latest form values.
• Since formValuesRef is a mutable reference, updating its current property doesn’t trigger rerenders in the component.

Benefits of Using useRef

Using useRef for value preservation offers several benefits:

1. Avoids Unnecessary Rerenders: By storing values in a mutable reference, we prevent rerenders caused by state updates, leading to better performance.
2. Preserves Data Across Renders: The values stored in useRef persist across re-renders, allowing us to preserve data without losing it when the component re-renders.
3. Flexible and Lightweight: useRef is a lightweight hook that doesn’t carry the overhead of managing component state. It’s suitable for preserving any type of data without the need for complex state management.

When to Use useRef

useRef is particularly useful in scenarios where:

• You need to store values that don’t affect the UI or trigger rerenders.
• You want to preserve data across component renders without the overhead of state management.
• You need a mutable reference to a value that persists across re-renders.

In React, managing state efficiently is crucial for building performant applications. By using React’s useRef hook, we can preserve values without causing unnecessary rerenders, leading to better performance and improved user experience. Whether it’s storing form values, caching data, or managing references, useRef provides a lightweight and flexible solution for value preservation in React applications.