ref forwarding

By default, each component’s DOM nodes are private. However, sometimes it’s useful to expose a DOM node to the parent—for example, to allow focusing it. To opt in, wrap your component definition into forwardRef():

import { forwardRef } from 'react';
 
const MyInput = forwardRef(function MyInput(props, ref) {
  const { label, ...otherProps } = props;
  return (
    <label>
      {label}
      <input {...otherProps} />
    </label>
  );
});

You will receive a ref as the second argument after props. Pass it to the DOM node that you want to expose:

import { forwardRef } from 'react';
 
const MyInput = forwardRef(function MyInput(props, ref) {
  const { label, ...otherProps } = props;
  return (
    <label>
      {label}
      <input {...otherProps} ref={ref} />
    </label>
  );
});

This lets the parent Form component access their <input> DOM node exposed by MyInput:

function Form() {
  const ref = useRef(null);
 
  function handleClick() {
    ref.current.focus();
  }
 
  return (
    <form>
      <MyInput label="Enter your name:" ref={ref} />
      <button type="button" onClick={handleClick}>
        Edit
      </button>
    </form>
  );
}

This Form component passes a ref to MyInput. The MyInput component forwards that ref to the <input> browser tag. As a result, the Form component can access that <input> DOM node and call focus() on it.