JSFiddle - React, Tailwind, and code Playground

HTML

<p id="p" contenteditable="true">Type here, not in the big textarea below</p>
<textarea rows="20" cols="80" id="log" readonly></textarea>

JavaScript

function log(msg) {
    document.getElementById("log").value += msg + "\n";
}

var p = document.getElementById("p");

p.onfocus = function() {
    log("focus");
};

if ("addEventListener" in p) {
    p.addEventListener("DOMCharacterDataModified", function() {
        log("DOMCharacterDataModified");
    }, false);
}