tests/scr-readingsystem-support_iframe_svg/EPUB/content_001.xhtml

<html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops" xml:lang="en">
  <head>
    <title>epubReadingSystem object support in an SVG within an iframe</title>
    <script>
      /**
       * A simple change that proves that scripting is enabled.
       * 
       * Note that the script is more complicated than would be necessary in HTML, due to the fact that the innerHTML method does not
       * seem to work in xhtml (only in html) :-(
       */ 
      function test_ers() {
        const support = document.getElementById('scripting_support');
        support.textContent = 'This reading system supports scripting.';

      }

      window.addEventListener('load', test_ers);
    </script>
  </head>
  <body>
    <p id="scripting_support">This Reading System does not support scripting.</p>

    <iframe src="iframe_content.svg" width="800" height="800" style="border: solid;" title="Embedded iframe with an SVG to check the availability of the epubReadingSystem object support"></iframe>

    <p>Note that the test relies on the availability of the <code>iframe</code> element in HTML. If no content appears above this line, this means the <code>iframe</code> is not available, and the test fails.</p>

  </body>
</html>