A function to embed yotube videos in markdown

embed-yotube-videos-in-md.ts

// This code looks for syntax like `{{youtube: https://www.youtube.com/watch?v=dQw4w9WgXcQ}}`
//    rather than a plain URL, but it should be simple enough to modify the regex.

// Call this function on your raw markdown before your markdown processor (e.g. Marked, ReMark, etc) is run on it,
//    and then pass the output of this function to your markdown processor.

function embedYoutubeVideos(md: string): string {
    const ytRegexGlobal = /{{youtube: ?([^{}]+)}}/g;
    const matches = md.matchAll(ytRegexGlobal);
    let output = md;
    try {
        for (const match of matches) {
            const video = new URL(match[1]);
            let videoID = video.searchParams.get("v");
            if (!videoID && video.hostname.includes("youtu.be")) {
                videoID = video.pathname.split("/")[1];
            }
            if (!videoID) return output;
            output = output.replace(
                match[0],
                `<iframe class="youtube-video" type="text/html" width="560" height="315" src="https://www.youtube.com/embed/${videoID}" frameborder="0" allow=" autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>\n`,
            );
        }
    } catch (err) {
        return output;
    }
    return output;
}