Improving regex for parsing YouTube / Vimeo URLs

Question

I\'ve made a function (in JavaScript) that takes an URL from either YouTube or Vimeo. It figures out the provider and ID for that particular video (demo: http://jsfiddle.net

Answer 1

I had a task to enable adding a dropbox videos. So the same input should take href, check it and transform to the playable link which I can then insert in .

const getPlayableUrl = (url) => {
    // Check youtube and vimeo
    let firstCheck = url.match(/(http:|https:|)\/\/(player.|www.)?(vimeo\.com|youtu(be\.com|\.be|be\.googleapis\.com))\/(video\/|embed\/|watch\?v=|v\/)?([A-Za-z0-9._%-]*)(\&\S+)?/);

    if (firstCheck) {
        if (RegExp.$3.indexOf('youtu') > -1) {
            return "//www.youtube.com/embed/" + RegExp.$6;
        } else if (RegExp.$3.indexOf('vimeo') > -1) {
            return 'https://player.vimeo.com/video/' + RegExp.$6
        }
    } else {
        // Check dropbox
        let candidate = ''
        if (url.indexOf('.mp4') !== -1) {
            candidate = url.slice(0, url.indexOf('.mp4') + 4)
        } else if (url.indexOf('.m4v') !== -1) {
            candidate = url.slice(0, url.indexOf('.m4v') + 4)
        } else if (url.indexOf('.webm') !== -1) {
            candidate = url.slice(0, url.indexOf('.webm') + 5)
        }

        let secondCheck = candidate.match(/(http:|https:|)\/\/(player.|www.)?(dropbox\.com)\/(s\/|embed\/|watch\?v=|v\/)?([A-Za-z0-9._%-]*\/)?(.*)/);
        if (secondCheck) {
            return 'https://dropbox.com/' + RegExp.$4 + RegExp.$5 + RegExp.$6 + '?raw=1'
        } else {
            throw Error("Not supported video resource.");
        }
    }
}