用 RSS 打造自己的阅读习惯

// 生成 RSS 订阅条目需要的信息
const generateRssItem = (post) => `
  <item>
    <guid>${siteMetadata.siteUrl}/blog/${post.slug}</guid>
    <title>${escape(post.title)}</title>
    <link>${siteMetadata.siteUrl}/blog/${post.slug}</link>
    ${post.summary && `<description>${escape(post.summary)}</description>`}
    <pubDate>${new Date(post.date).toUTCString()}</pubDate>
    <author>${siteMetadata.email} (${siteMetadata.author})</author>
    ${post.tags && post.tags.map((t) => `<category>${t}</category>`).join('')}
  </item>
`

const generateRss = (posts, page = 'feed.xml') => `
  <rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
    <channel>
      <title>${escape(siteMetadata.title)}</title>
      <link>${siteMetadata.siteUrl}/blog</link>
      <description>${escape(siteMetadata.description)}</description>
      <language>${siteMetadata.language}</language>
      <managingEditor>${siteMetadata.email} (${siteMetadata.author})</managingEditor>
      <webMaster>${siteMetadata.email} (${siteMetadata.author})</webMaster>
      <lastBuildDate>${new Date(posts[0].date).toUTCString()}</lastBuildDate>
      <atom:link href="${siteMetadata.siteUrl}/${page}" rel="self" type="application/rss+xml"/>
      ${posts.map(generateRssItem).join('')}
    </channel>
  </rss>
`

// 以 next.js 为例在生成页面的时候生成 feed.xml RSS 订阅源文件
export async function getStaticProps({ params }) {
  const allPosts = await getAllFilesFrontMatter('blog')
  const postIndex = allPosts.findIndex((post) => formatSlug(post.slug) === params.slug.join('/'))
  const prev = allPosts[postIndex + 1] || null
  const next = allPosts[postIndex - 1] || null
  const post = await getFileBySlug('blog', params.slug.join('/'))
  const authorList = post.frontMatter.authors || ['default']
  const authorPromise = authorList.map(async (author) => {
    const authorResults = await getFileBySlug('authors', [author])
    return authorResults.frontMatter
  })
  const authorDetails = await Promise.all(authorPromise)

  // rss
  const rss = generateRss(allPosts)
  fs.writeFileSync('./public/feed.xml', rss)

  return { props: { post, authorDetails, prev, next } }
}