JSFiddle - React, Tailwind, and code Playground
HTML
<script src="http://rangyinputs.googlecode.com/svn/trunk/rangyinputs_jquery.js"></script>
<input type="button" onmousedown="insertImg(); return false" value="Insert">
<textarea id="body" rows="5" cols="50">Click in here somewhere and click the button to insert image</textarea>
JavaScript
function insertImg() {
var $textarea = $("#body");
var text = "path to image file"
$textarea.replaceSelectedText(text, "select");
$textarea.surroundSelectedText("[img]", "[/img]");
}