Get a list of video metadata of any public or private youtube playlist (title, id, time left, channel, url) as a json file

get_youtube_playlist_json.js

// Modifier: user237
// Forked from: https://gist.github.com/silver-mixer/43009c048a5e7e60f2182198ad0a105b
// Description: To download a list of video metadata of any public or private youtube playlist, as a json document, run this script on the playlist page.
// date created: 2023-09-02

(() => {
	const VERSION = "user237_v1";
    const REGEX_LIST_ID = /\?list=([a-zA-Z0-9-_]+)($|&)/;
    const REGEX_TIMELEFT = /t=([0-9]+)/; // get the first capture group using [1]

    // location.href refers to the current URL 
	let list_id = location.href.match(REGEX_LIST_ID)[1];
	// let list_id = location.href.match(/\?list=([a-zA-Z0-9-_]+)($|&)/)[1];
    
    // TEST1 - print the id
    console.log(list_id);
    
	let title = document.title;
    console.log(title);

	let created_at = Date.now();
	let videos = [];
	document.querySelectorAll('ytd-playlist-video-renderer').forEach(e => {
        let id = e.querySelector('a').href.match(/\?v=([a-zA-Z0-9-_]+)($|&)/)[1];
        let time_left = e.querySelector('a').href.match(REGEX_TIMELEFT);
        time_left = time_left ? time_left[1] : '0';
		videos.push({
			title: e.querySelector('#video-title').innerText,
			id: id,
            time_left_secs: time_left,
            // URL has to be in format https://www.youtube.com/watch?v=VIDEO_ID&t=TIME_LEFT
            // generate from title and id
            URL: "https://www.youtube.com/watch?v=" + id + "&t=" + time_left,
			channel: e.querySelector('#channel-name').innerText
		});
	});
	let data = {
		version: VERSION,
		title: title,
		id: list_id,
		created_at: created_at,
		videos: videos
	};
	let a = document.createElement('a');
	a.href = URL.createObjectURL(new Blob([JSON.stringify(data)], {type: 'text/plain'}));
	a.download = 'playlist_' + list_id + '.json';
	a.click();
})();