Example sitemap sync from WP to NextJS

sitemap.xml.ts

import { GetServerSidePropsContext } from "next";

const defaultWpUrl = 'https://example.wpengine.com';
const localHost = 'localhost:3000';
const prodHost = 'example.com';

export default function Sitemap () {};


export const getServerSideProps = async (context: GetServerSidePropsContext) => {

  let wpUrl = process.env.NEXT_PUBLIC_WORDPRESS_URL ?? defaultWpUrl;

  if (wpUrl?.endsWith('/')) {
      wpUrl = wpUrl.substr(0, wpUrl.length - 1);
  }

  const { hostname } = new URL(wpUrl);
  const clientHost = process.env.NODE_ENV === 'development' ? localHost : prodHost;

  const xmlRes = await fetch(wpUrl + context.req.url);
  let xml = (await xmlRes.text());

  // change server locations to client loctions
  xml = xml.replace(new RegExp(hostname, 'g'), clientHost);
  // change client locations for images back to server locations
  xml = xml.replace(new RegExp(`${clientHost}/wp-content/uploads`, 'g'), `${hostname}/wp-content/uploads`);

  context.res.setHeader('Content-Type', 'text/xml');
  context.res.write(xml);
  context.res.end();

  return {
    props: {}
  };
};