JSFiddle - React, Tailwind, and code Playground

by Jon Eyrick

HTML

<form action="upload.php" enctype="multipart/form-data" method="POST" id="uploadform">
    <input id="openFile" name="img" type="file" />
</form>

JavaScript

$(document).ready(function () {
    function upload(files, event) {
        console.log($(this).find('#openFile').files[0].size);
    }

    $('#openFile').on('change', function (evt) {
        var formData = new FormData($('#uploadform')[0]);

        upload(formData, evt);
        return false;
    });
});