generateRssFeed.js

const fs = require("fs");
const glob = require("glob");
const yaml = require("yaml");
const markdownIt = require("markdown-it");
// helper functions

const getMetaData = function (mdFile) {
	const buffer = fs.readFileSync(mdFile);
	const fileContent = buffer.toString();
	let metadata = {};

	const metas = /---(.*?)---/s.exec(fileContent);
	if (metas.length > 0) {
		const clearMeta = metas[0].replaceAll("---", "");
		try {
			metadata = yaml.parse(clearMeta);
		} catch ($e) {}
	}

	return metadata;
};

const clearHTMLTags = function (str) {
	return str.replace(/(<([^>]+)>)/gi, "");
}

const getDescriptionFromBody = function (mdFile) {
	const buffer = fs.readFileSync(mdFile);
	let fileContent = buffer.toString();

	// clear meta data
	const metas = /---(.*?)---/s.exec(fileContent);
	if (metas.length > 0) {
		fileContent = fileContent.replaceAll(metas[0], "");
	}

	//try to get first n character as plain text
	let body = "";

	try {
		let md = new markdownIt({
			html: true,
			linkify: true,
			typographer: true,
		});

		body = md.render(fileContent);
		body = clearHTMLTags(body);
		body = body.slice(0, 160) + "...";
	} catch (e) { }

	return body;
};

const uuidv4 = function () {
	let part1 = Date.now().toString(36) + Math.random().toString(36).substring(2);
	let part2 = Date.now().toString(36) + Math.random().toString(36).substring(2);

	return `${part1}-${part2}`;
};

// main process

const langs = ["en", "cn"];
const website = "https://etccooperative.org";

for (const lang of langs) {
	const folder = `./src/contents/posts/${lang}`;

	let xml = "";
	let items = "";

	fs.readdirSync(folder)
		.reverse()
		.forEach((file) => {
			const mdFiles = glob.globSync(`${folder}/${file}/*.md`);
			if (mdFiles.length > 0) {
				const mdFile = mdFiles[0];

				const metadata = getMetaData(mdFile);
				const description = getDescriptionFromBody(mdFile);

				items += `<item>
                    <guid isPermaLink="false">${uuidv4()}</guid>
                    <title>${metadata.title.replace('&', '&amp;') || ""}</title>
                    <link>${website}/posts/${file}</link>
                    <description>${description}</description>
					<media:content medium="image" url="${website}/img/posts/featuredImg/${metadata.featuredImage || ""}" width="385" height="200" />
				</item>`;

				xml = `<?xml version="1.0" encoding="UTF-8" ?>
                <rss version="2.0"
                  xml:base="https://www.trtworld.com" 
                  xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom"
                  xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:foaf="http://xmlns.com/foaf/0.1/"
                  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
                  xmlns:media="http://search.yahoo.com/mrss/">
                <channel>
                  <atom:link href="${website}/rss/feed.${lang}.xml" rel="self" type="application/rss+xml"/>
                  <title>ETC Cooperative</title>
                  <link>${website}</link>
                  <description>See latest post from ETC Cooperative</description>
                  ${items}
                </channel>
                </rss>`;
			}
		});

	fs.writeFileSync(`./public/rss/feed.${lang}.xml`, xml);
}