javascripthtmlclipboard

Clear clipboard to prohibit unauthorised copying, insert message?

Is it possible to write your own message into the clipboard when copying website data using ctrl+c? I've found some Javascript that clears the clipboard - would be interesting to know if there's something that would write to it as well, i.e. replace the text in the clipboard with something like 'Please use the print edition of our website'.

  function clearData() {
    window.clipboardData.setData('text', '')
  }

  function cldata() {
    if (clipboardData) {
      clipboardData.clearData();
    }
  }
  setInterval("cldata()", 1000);
<body ondragstart="return false;" onselectstart="return false;" oncontextmenu="return false;" onload="clearData();" onblur="clearData();">

  <h1>Example text</h1>
<input type="text">

Solution

  • You can't do it purely through JavaScript.

    JavaScript editing of the clipboard is considered a security vulnerability (and there is much more discussion on this).

    You could do it through hacks that uses Flash for clipboard access interacting with JavaScript.