JSFiddle - React, Tailwind, and code Playground
by Luke Marlow
HTML
<script src="https://code.jquery.com/jquery-1.12.0.min.js"></script>
<input type="hidden" id="fullname" value="Mr Marlow">
<textarea style="width: 100%; height: 200px;" id="email_body">
[FULLNAME]
[FULLNAME]
[FULLNAME]
</textarea>
<hr style="width: 50%;">
<button id="addName">addName</button>
<button id="codeAlt">codeAlt</button>
JavaScript
$('#addName').click(function(e) {
e.preventDefault();
$('#email_body').val($('#email_body').val().replace(/\[FULLNAME\]/g, $('#fullname').val()));
});
$("#codeAlt").click(function(e) {
e.preventDefault();
$('#email_body').val($('#email_body').val().replace($('#fullname').val(), '[FULLNAME]'));
});