React hooks provide a powerful way to manage stateful logic in our functional components. One of the useful hooks is useImperativeHandle, which allows us to customize the instance value that is exposed to parent components when using the ref prop.

In this article, we’ll explore how to use the useImperativeHandle hook in React to provide a custom interface to parent components through the ref prop.

What is the useImperativeHandle Hook?

Normally, when we create a ref in a functional component, the ref.current value points to the component instance or DOM node. However, sometimes we need to expose a specific set of functions or values to the parent component, hiding other internal details.

The useImperativeHandle hook gives us control over the instance value that gets exposed to the parent component. It allows us to define a set of functions or values to be exposed through the ref prop, without exposing the entire component instance.

Using useImperativeHandle

Here’s an example that demonstrates how to use the useImperativeHandle hook to expose a specific function through the ref prop.

import React, { useRef, useImperativeHandle, forwardRef } from 'react';

// Child component
const FancyInput = forwardRef((props, ref) => {
  const inputRef = useRef(null);

  const focusInput = () => {
    inputRef.current.focus();
  };

  // Expose `focusInput` function through the `ref` prop
  useImperativeHandle(ref, () => ({
    focus: focusInput
  }));

  return <input type="text" ref={inputRef} />;
});

// Parent component
const App = () => {
  const fancyInputRef = useRef(null);

  const handleButtonClick = () => {
    // Call the focus function on the child component
    fancyInputRef.current.focus();
  };

  return (
    <div>
      <FancyInput ref={fancyInputRef} />
      <button onClick={handleButtonClick}>Focus Input</button>
    </div>
  );
};

export default App;

In the above example, we create a child component called FancyInput. Inside the child component, we define a function focusInput that sets the focus on the input element. We then use the useImperativeHandle hook to expose the focusInput function through the ref prop.

In the parent component, we create a ref using the useRef hook and assign it to the FancyInput component. This allows us to access the child component’s focusInput function and call it when the button is clicked.

Conclusion

The useImperativeHandle hook in React is a powerful tool for exposing a custom interface from child components to their parent components. It allows us to selectively expose functions or values without giving access to the complete component instance. This can be useful when we need to provide a more controlled API to parent components.

By mastering hooks like useImperativeHandle, we can build more flexible and reusable components in our React applications.

Happy coding! 🚀

#React #Hooks