t_wの輪郭

import { Post } from "@/models";
import React from "react";
import { renderToString } from 'react-dom/server';

declare global {
  namespace JSX {
    interface IntrinsicElements {
      [elemName: string]: unknown;
    }
  }
}

export function RssFeed({ posts }: { posts: Post[] }) {
  return renderToString(
    <rss version='2.0'>
      <channel>
        <language>ja</language>
        <title>t_wの輪郭</title>
        <rsslink>https://towasys.com/</rsslink>
        <description>t_wの輪郭のRSSです。</description>
        {posts.map(post => <item>
          <title>{(post.title ? post.title : "あれ") + "|" + post.kno}</title>
          <description>{post.body_html ?? ""}</description>
          {post.posted_at && <pubDate>{new Date(post.posted_at * 1000).toUTCString()}</pubDate>}
          <rsslink>{`https://towasys.com/${post.kno}`}</rsslink>
          <guid isPermaLink="true">{`https://towasys.com/${post.kno}`}</guid>
        </item>)}
      </channel>
    </rss>
  ).replaceAll("rsslink", "link")
}

Next.jsでの使い方

getServerSidePropsで下記を実行

const rss_feed = RssFeed({ posts })
context.res.statusCode = 200
context.res.setHeader('Cache-Control', 's-maxage=86400, stale-while-revalidate') // 24時間キャッシュする
context.res.setHeader('Content-Type', 'text/xml')
context.res.end(rss_feed)
return {
    props: {},
}