JSFiddle - React, Tailwind, and code Playground

HTML

<div id="foo-barred"><iframe width="640"height="390"frameborder="0"title="YouTube video player"type="text/html"src="http://www.youtube.com/embed/u1zgFlCw8Aw?enablejsapi=1"></iframe></div>

JavaScript

function getFrameID(id){
        var elem = document.getElementById(id);
        if (elem) {
            if(/^iframe$/i.test(elem.tagName)) return id;//Frame, OK
            // else: Look for frame
            var elems = elem.getElementsByTagName("iframe");
            if (!elems.length) return null; //No iframe found, FAILURE
            for (var i=0; i<elems.length; i++) {
               if (/^https?:\/\/(?:www\.)?youtube(?:-nocookie)?\.com(\/|$)/i.test(elems[i].src)) break;
            }
            elem = elems[i]; //The only, or the best iFrame
            if (elem.id) return elem.id; //Existing ID, return it
            // else: Create a new ID
            do { //Keep postfixing `-frame` until the ID is unique
                id += "-frame";
            } while (document.getElementById(id));
            elem.id = id;
            return id;
        }
        // If no element, return null.
        return null;
    }

    // Define YT_ready function.
    var YT_ready = (function(){
        var onReady_funcs = [], api_isReady = false;
        /* @param func function     Function to execute on ready
         * @param func Boolean      If true, all qeued functions are executed
         * @param b_before Boolean  If true, the func will added to the first
                                     position in the queue*/
        return function(func, b_before){
            if (func === true) {
                api_isReady = true;
                for (var i=0; i<onReady_funcs.length; i++){
                    // Removes the first func from the array, and execute func
                    onReady_funcs.shift()();
                }
            }
            else if(typeof func == "function") {
                if (api_isReady) func();
                else onReady_funcs[b_before?"unshift":"push"](func); 
            }
        }
    })();
    // This function will be called when the API is fully loaded
    function onYouTubePlayerAPIReady() {YT_ready(true)}

    // Load YouTube...