category bestand alpha filter

kit/js/custom.js

@@ -1,6 +1,24 @@
 document.addEventListener("DOMContentLoaded", function() {
   $("ul.catFilter li.available").on("click", function(e){
+    
     e.preventDefault();
-    console.log("test");
+
+    var catFilter = document.getElementsByClassName("catFilter")[0];
+    var catElement = catFilter.querySelector('.active');
+    catElement.classList.remove('active');
+    this.classList.add('active');
+
+
+    var requestLetter = $(this).find('a:first').text().trim();
+    var lists = document.getElementsByClassName("bestandliste");
+    for (let list of lists) {
+      var listLetter = list.id;
+      if (listLetter != requestLetter && requestLetter != "Alle") {
+        list.style.display = "none";
+      } else {
+        list.style.display = "block";
+      };
+    }
+
   });
 });