Make dropdown work with keyboard navigation

Author: doubleedesign

src/javascript/vanilla-js-dropdown.js

@@ -63,6 +63,11 @@ var CustomSelect = function(options) {
   selectContainer.appendChild(ul);
 
   selectContainer.addEventListener('click', onClick);
+  selectContainer.addEventListener('keypress', function(event) {
+		if (event.key === 'Enter') {
+			onClick(event);
+		}
+	});
 
   // pseudo-select is ready - append it and hide the original
   elem.parentNode.insertBefore(selectContainer, elem);
@@ -80,6 +85,7 @@ var CustomSelect = function(options) {
       li.innerText = options[i].textContent;
       li.setAttribute('data-value', options[i].value);
       li.setAttribute('data-index', index++);
+      li.setAttribute('tabindex', '0');
 
       if (selectOptions[elem.selectedIndex].textContent === options[i].textContent) {
         li.classList.add(selectedClass);