JSFiddle - React, Tailwind, and code Playground

HTML

<input type="file" id="myfile" />
<p id="sel">Data will appear here</p>

JavaScript

function readFile(evt) {
    var files = evt.target.files;
    var file = files[0];
    var reader = new FileReader();
    // reader.onload = function() {
    // console.log(this.result);
    // }
    reader.readAsText(file)
    reader.onload = function (e) {
        alert("FILE LOADED");
        var f = reader.result;

        document.getElementById("sel").innerHTML = f;
    }
}


$(document).ready(function () {
    //adding mouse up listener to get selected text from left pane
    document.getElementById('myfile').addEventListener('change', readFile, false);
});