index.html

<html>
    <head>
      <script>
        // flask parameter: change it to unique, to not let browser cache the file
        path = "{{ unique_url_for_PATH(path) }}"
      </script>

      <frameset rows = "7%, *" border="1">
        <frame name = "title"  sandbox="allow-top-navigation" src="src/title.html" noresize="noresize">
        <frameset id="horizontal" cols="57%, *">
          <frameset rows="76%, *">
            <frameset cols="13%, *">
              <frame name="controls" src="src/controls.html" noresize="noresize">
              <frame name="tree" src="src/tree.html">
            </frameset>
            <frame name = "chain" src="src/chain.html">
          </frameset>
          <frame name = "choices" src="src/choices.html">
        </frameset>
      </frameset>
    </head>

    <body>
    </body>
</html>