<?xml version="1.0" encoding="utf-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Selection drag and drop to textarea in iframe</title>
<style type="text/css">
iframe
  {width:500px;
  height:400px;
  border-style:none;}
</style>
</head>
<body onload="window.getSelection().selectAllChildren(document.querySelector('p'))">
<p>Drag me</p>
<p>Drag selected text to the textarea. Copy of selection should end up in the textarea once you drop it there.</p>
<p><iframe src="helper-drop-here-textarea.xhtml">XHTML document</iframe></p>
</body>
</html>