JSFiddle - React, Tailwind, and code Playground
HTML
<form action="#" method="post">
<fieldset>
<input type="file" />
</fieldset>
<fieldset>
<input type="submit" />
</fieldset>
</form>
JavaScript
$(document).ready(
function(){
$('input:submit').attr('disabled',true);
$('input:file').change(
function(){
if ($(this).val()){
$('input:submit').removeAttr('disabled');
}
else {
$('input:submit').attr('disabled',true);
}
});
}
);