Widget:ToggleFolioNumbers

<script> (function() {

 function init() {
   var folios = parent.document.querySelectorAll('span.folio-number');
   if (!folios.length) return;

   var container = parent.document.querySelector('#Tibetan_Text .oo-ui-fieldsetLayout-group');
   if (!container) return;

   var visible = false;
   var link = parent.document.createElement('a');
   link.href = '#';
   link.textContent = 'Show folio numbers';

   link.onclick = function(e) {
     e.preventDefault();
     visible = !visible;
     for (var i = 0; i < folios.length; i++) {
       folios[i].style.display = visible ?  : 'none';
     }
     link.textContent = visible ? 'Hide folio numbers' : 'Show folio numbers';
   };

   for (var i = 0; i < folios.length; i++) {
     folios[i].style.display = 'none';
   }

   var div = parent.document.createElement('div');
   div.style.textAlign = 'right';
   div.appendChild(link);
   container.insertBefore(div, container.firstChild);
 }

 var observer = new MutationObserver(function(mutations, obs) {
   var container = parent.document.querySelector('#Tibetan_Text .oo-ui-fieldsetLayout-group');
   if (container) {
     obs.disconnect();
     init();
   }
 });

 observer.observe(parent.document.body, { childList: true, subtree: true });

})();

</script>