css/selectors/dir-style-04.html

<!DOCTYPE html>
<html class="reftest-wait">
  <head>
    <meta charset="UTF-8">
    <title>CSS Test: :dir() selector</title>
    <link rel="author" title="Astley Chen" href="mailto:aschen@mozilla.com">
    <link rel="author" title="Mozilla" href="https://www.mozilla.org">
    <link rel="help" href="https://drafts.csswg.org/selectors-4/#the-dir-pseudo">
    <meta name="assert" content="Test checks :dir() basic functions on runtime added elements.">
    <link rel="match" href="dir-style-04-ref.html">
    <style>
      :dir(ltr) { color: blue }
      :dir(rtl) { color: lime }
      div { text-align: left; }
    </style>
    <script>
      function appendChildren(e)
      {
        // ensure it's a dynamic change
        document.documentElement.getBoundingClientRect();

        var x = document.createElement("span");
        x.innerHTML = "This span should inherit dir from the parent. ";

        var y = document.createElement("span");
        y.innerHTML = "This span should inherit dir from the grandparent.";

        var div = document.getElementById(e);

        x.appendChild(y);
        div.appendChild(x);

        document.documentElement.removeAttribute("class");
      }
    </script>
  </head>
  <body onload="appendChildren('d1');appendChildren('d2');">
    <div id="d1" dir="ltr">This element is ltr. </div>
    <div id="d2" dir="rtl">This element is rtl. </div>
  </body>
</html>