JSFiddle - React, Tailwind, and code Playground

HTML

<div id="buttoncontainer">
    <input id="button" onclick="myScope.update();" type="button" value="Update page">
</div>
<div id="tryitcontainer">
    <textarea id="codebox"></textarea>
    <iframe id="showpage"></iframe>
</div>

JavaScript

window.myScope = {
    update: function() {
        var div = document.createElement('div'),
            codeinput = document.getElementById('codebox').value,
            scriptcode = "";
        
        div.innerHTML = codeinput;
        Array.prototype.slice.apply(div.querySelectorAll("script")).forEach(function(script) {
            scriptcode += script.innerHTML;
            div.removeChild(script);
        });
        window.frames[0].document.body.appendChild(div);
        // hackers love to see user input converted to this... just saying
        eval(scriptcode);
    }
};