Re-render React component when prop changes

Re-render React component when prop changes

React is a popular JavaScript library for building user interfaces. One common problem that developers face is how to re-render a React component when a prop changes. In this blog post, we will explore different solutions to this problem.

Solution 1: Using componentDidUpdate

The componentDidUpdate lifecycle method is called after a component’s props or state have been updated. We can use this method to check if the prop we are interested in has changed, and then trigger a re-render of the component.

Here’s an example:

{`class MyComponent extends React.Component {
  componentDidUpdate(prevProps) {
    if (this.props.myProp !== prevProps.myProp) {
      // Prop has changed, trigger a re-render
      this.forceUpdate();
    }
  }

  render() {
    // Render component
  }
}`}

In the above example, we compare the current value of the prop myProp with its previous value using the prevProps argument. If the values are different, we call the forceUpdate method to trigger a re-render of the component.

Solution 2: Using React.memo

If you are using functional components, you can use the React.memo higher-order component to memoize the component and re-render it only when its props change.

Here’s an example:

{`const MyComponent = React.memo((props) => {
  // Render component
});`}

In the above example, the React.memo function wraps the functional component MyComponent. It checks if the props of the component have changed since the last render, and only re-renders the component if necessary.

Solution 3: Using key prop

Another approach is to use the key prop of a component to force React to re-render it when the prop changes.

Here’s an example:

{`class MyComponent extends React.Component {
  render() {
    return (
      

        // Render component
      
    );
  }
}`}

In the above example, we set the key prop of the component’s root element to the value of the prop we are interested in. This tells React that the component should be re-rendered when the prop changes.

These are three different solutions to re-render a React component when a prop changes. Choose the one that best fits your use case and enjoy building dynamic and responsive user interfaces with React!

Final HTML Output:

<

pre>{`

{`class MyComponent extends React.Component {
  componentDidUpdate(prevProps) {
    if (this.props.myProp !== prevProps.myProp) {
      // Prop has changed, trigger a re-render
      this.forceUpdate();
    }
  }

  render() {
    // Render component
  }
}`}

{`const MyComponent = React.memo((props) => {
  // Render component
});`}

{`class MyComponent extends React.Component {
  render() {
    return (
      

        // Render component
      
    );
  }
}`}