astro-rssでのRSSの改善とモジュール化

import rss, { pagesGlobToRssItems } from '@astrojs/rss';

export async function GET(context) {
  return rss({
    title: 'Astro学習者 | ブログ',
    description: 'Astroを学ぶ旅',
    site: context.site,
    items: await pagesGlobToRssItems(import.meta.glob('./**/*.md')),
    customData: `<language>ja-jp</language>`,
  });
}

import rss from '@astrojs/rss';
import { getCollection } from 'astro:content';
import siteInfo from '@/data/siteInfo';

export async function GET(context) {
  const blogs = await getCollection('blog');
  return rss({
    title: siteInfo.appName,
    description: siteInfo.description,
    site: context.site,
    items: blogs.map(blog => ({
      title: blog.data.title,
      pubDate: blog.data.pubDate,
      description: blog.data.description,
      customData: blog.data.customData,
      link: `/blog/${blog.slug}/`,
    })),
    customData: `<language>ja-jp</language>`,
  });
}

<rss version="2.0" data-google-analytics-opt-out="">
    <channel>
        <title>Rowicy</title>
        <description>RowicyのWebサイトです。</description>
        <link>https://www.rowicy.com/</link>
        <language>ja-jp</language>

        <item>
            <title>includeで引数に応じて出力の分岐をする方法</title>
            <link>https://www.rowicy.com/blog/ejs-include-argument/</link>
            <guid isPermaLink="true">https://www.rowicy.com/blog/ejs-include-argument/</guid>
            <description>EJSのincludeで引数に応じて出力の分岐を行う方法をご紹介します。</description>
            <pubDate>Tue, 14 Mar 2023 00:00:00 GMT</pubDate>
        </item>
        ...

<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <title>Sample Blog Title</title>
    <link>https://example.com/</link>
    <description>This is a sample RSS feed description.</description>
    <lastBuildDate>Tue, 01 Jan 2025 12:00:00 +0000</lastBuildDate>
    <docs>https://example.com/rss-spec</docs>
    <generator>Sample::RSS::Generator</generator>

    <item>
      <title>Sample Article Title</title>
      <link>https://example.com/articles/sample-article</link>
      <description>
        This is a sample article description.
        It can contain plain text or HTML content.
      </description>
      <pubDate>Tue, 01 Jan 2025 10:00:00 +0000</pubDate>
      <guid isPermaLink="false">sample://entry/1234567890</guid>
      <category>Technology</category>
      <category>Web</category>
      <category>Sample</category>
      <enclosure
        url="https://example.com/images/sample-image.png"
        type="image/png"
        length="0"
      />
    </item>
  ...

const blogs = await getCollection('blog');
return rss({
  title: siteInfo.appName,
  description: siteInfo.description,
  site: context.site,
  items: blogs.map(blog => ({
    title: blog.data.title,
    pubDate: blog.data.pubDate,
    description: blog.data.description,
    customData: blog.data.customData,
    link: `/blog/${blog.slug}/`,
      categories: blog.data.tags,
      enclosure: {
       url: `/og/${blog.slug}.png`,
       type: 'image/png',
       length: 0,
     },

  })),
  customData: `<language>ja-jp</language>`,
});

function extractImageUrl(body: string) {
  if (!body) return null;
  const relativeImages = [];
  const absoluteImages = [];
  const imgTagRegex = /<img[^>]+src=["']([^"']+)["'][^>]*>/g;
  const mdImageRegex = /!\[^\](^\)*\]\(([^)]+)\)/g;

  const imgMatches = [...body.matchAll(imgTagRegex)];
  const mdMatches = [...body.matchAll(mdImageRegex)];
  const allUrls = [
    ...imgMatches.map(match => match[1]),
    ...mdMatches.map(match => match[1]),
  ];

  if (allUrls.length === 0) return null;

  for (const url of allUrls) {
    const isRelative = url.startsWith('/');
    let fullUrl = url;
    const ext = fullUrl.split('?')[0].split('.').pop()?.toLowerCase();
    let type;

    switch (ext) {
      case 'jpg':
      case 'jpeg':
        type = 'image/jpeg';
        break;
      case 'png':
        type = 'image/png';
        break;
      case 'gif':
        type = 'image/gif';
        break;
      case 'webp':
        type = 'image/webp';
        break;
      case 'svg':
        type = 'image/svg+xml';
        break;
      default:
        continue;
    }

    const imageObj = {
      url: fullUrl,
      type: type,
      length: 0,
    };

    if (isRelative) {
      relativeImages.push(imageObj);
    } else {
      absoluteImages.push(imageObj);
    }
  }

  const images = [...relativeImages, ...absoluteImages];
  return images.length > 0 ? images : null;
}

      enclosure: extractImageUrl(blog.body)?.[0] || {
        url: `/og/${blog.slug}.png`,
        type: 'image/png',
        length: 0,
      },

async function getFeed( siteUrl: string, maxItems?: number, filter?: { tag?: string; author?: string }) {

// ...
  const rssOptions: RSSOptions = {

    items: blogs.map(blog => ({
      title: blog.data.title,
      pubDate: new Date(blog.data.pubDate),
      description: blog.data.description,
      link: blog.data.externalUrl
        ? blog.data.externalUrl
        : `/blog/${blog.slug}/`,
      categories: blog.data.tags,
      enclosure: extractImageUrl(blog.body)?.[0] || {
        url: `/og/${blog.slug}.png`,
        type: 'image/png',
        length: 0,
      },
    })),
    customData: `<language>ja-jp</language>`,
  };
  return rssOptions;
}
export { getFeed };