Not able to focus on input when i use useImperativeHandle-CodePudding

Here is my code: I have created the input component and header component. if I comment on the useImperativeHandle hook, input focus is working fine. please check this code.

import { forwardRef, useImperativeHandle, useRef } from "react";

const Input = forwardRef((props, ref) => {
  // here is useImperativeHandle
  useImperativeHandle(ref, () => ({
    // ```method```
    someExposedProperty: () => {
      alert("inside the exposed property function!");
    }
  }));
  // Return statement
  return (
    <>
      <input type="text" ref={ref} />
    </>
  );
});
// header component
export default function Header() {
  const inputRef = useRef();
  return (
    <>
      <div className="container">
        <Input ref={inputRef} />
      </div>
      <button
        // Click function.
        onClick={() => {
          inputRef.current.focus();
        }}
      >
        Add focus
      </button>
    </>
  );
}

CodePudding user response：

You need two refs here. One to bind the functions (which are going to expose to the outside) and another to keep a reference to the input element (this one is only used inside the Input and not exposed to outside components).

Try like below:

import { forwardRef, useImperativeHandle, useRef } from "react";

const Input = forwardRef((props, ref) => {
  const inputRef = useRef();

  useImperativeHandle(
    ref,
    () => ({
      focus: () => {
        inputRef.current.focus();
      }
    }),
    []
  );
  return (
    <>
      <input type="text" ref={inputRef} />
    </>
  );
});
export default function Header() {
  const inputRef = useRef();
  return (
    <>
      <div className="container">
        <Input ref={inputRef} />
      </div>
      <button
        onClick={() => {
          inputRef.current.focus();
        }}
      >
        Add focus
      </button>
    </>
  );
}

Working Demo