[SOLVED] NextJS 13 Hydration failed error, when using Modal Component

NextJS 13 Hydration failed error, when using Modal Component

Hello I am using the SRC folder with APP router nextjs 13 and trying to set up simple Modal message, which is visualized correctly, but throws the following Error in the Console:

Error: Hydration failed because the initial UI does not match what was rendered on the server. Warning: Expected server HTML to contain a matching in .

I've tried to put the modal in different places, in the layout.tsx, in provider, in page, as a component, or directly in the page, with wrapping div and <></> but with no luck. I guess this has something to do with the fact that when I inspect the code, the code of the modal is always just after the body tag, and not where the component code is positioned.

layout.tsx


...

return (
    <html lang="en">
      <body className="min-h-screen">
        <Providers>{children}</Providers>
        {/* Allow more height for mobile menu on mobile */}
        <div className="h-40 md:hidden" />
      </body>
    </html>
  );

page.jsx

import Modal from "react-bootstrap/Modal";
export default function Home() {
 return (
    <>
      <SomeComponents/>
<Modal show={true}>Text</Modal>
    </>
  );
}

I have tried with clean skeleton nextjs13 with the same result.

Solution

Use useEffect for setting state true, dont set true directly. here is a sample code.

import { useEffect, useState } from 'react';
import Button from 'react-bootstrap/Button';
import Modal from 'react-bootstrap/Modal';

interface PopupProps {
    item: any
}
function Popup({ item }: PopupProps) {

    const [show, setShow] = useState(false);

    const handleClose = () => setShow(false);
    const handleShow = () => setShow(true);

    useEffect(() => {
        setShow(true);  // <---- 
      }, []);

    return (
        <div>
            <Modal show={show} onHide={handleClose}
                size='lg'
                centered
                className={`old-modal`}
                keyboard={true}>
                <Modal.Header closeButton>
                    <Modal.Title>Modal heading</Modal.Title>
                </Modal.Header>
                <Modal.Body>Woohoo, you are reading this text in a modal! 
                </Modal.Body>
            
            </Modal>
        </div>
    );
}

export default Popup;