Add aria attributes

Author: doubleedesign

src/javascript/vanilla-js-dropdown.js

@@ -39,10 +39,12 @@ var CustomSelect = function(options) {
 
   button.className = titleClass;
   button.textContent = selectOptions[0].textContent;
+  button.setAttribute('aria-expanded', false);
 
   // creating the UL
   var ul = document.createElement('ul');
   ul.className = listClass;
+  ul.setAttribute('aria-hidden', true);
 
   // dealing with optgroups
   if (selectOpgroups.length) {
@@ -143,7 +145,9 @@ var CustomSelect = function(options) {
    */
   function toggle() {
     ul.classList.toggle(openClass);
+    ul.toggleAttribute('aria-hidden');
     button.classList.toggle(openClass);
+    button.toggleAttribute('aria-expanded');
   }
 
   /**
@@ -153,7 +157,9 @@ var CustomSelect = function(options) {
    */
   function open() {
     ul.classList.add(openClass);
+    ul.setAttribute('aria-hidden', false);
     button.classList.add(openClass);
+    button.setAttribute('aria-expanded', true);
   }
 
   /**
@@ -163,7 +169,9 @@ var CustomSelect = function(options) {
    */
   function close() {
     ul.classList.remove(openClass);
+    ul.setAttribute('aria-hidden', true);
     button.classList.remove(openClass);
+    button.setAttribute('aria-expanded', false);
   }
 
   return {