diff --git a/src/customCategory.php b/src/customCategory.php
index eb7e331c..e752a106 100644
--- a/src/customCategory.php
+++ b/src/customCategory.php
@@ -1,12 +1,57 @@
 <?php
-function ajax_customCategory ($param, $content) {
-  global $db;
+class CustomCategoryRepository {
+  function clearCache () {
+  }
 
-  if (!$db) {
-    return null;
+  function getCategory ($id, $options=[]) {
+    global $db;
+
+    $stmt = $db->prepare("select content from customCategory where id=:id");
+    $stmt->bindValue(':id', $id, PDO::PARAM_STR);
+    if ($stmt->execute()) {
+      $row = $stmt->fetch(PDO::FETCH_ASSOC);
+      $result = $row['content'];
+      $stmt->closeCursor();
+
+      return $result;
+    }
   }
 
-  if (isset($param['action']) && $param['action'] === 'list') {
+  function recordAccess ($id) {
+    global $db;
+
+    if (!isset($_SESSION['customCategoryAccess'])) {
+      $_SESSION['customCategoryAccess'] = [];
+    }
+
+    // update access per session only once a day
+    if (array_key_exists($id, $_SESSION['customCategoryAccess']) && $_SESSION['customCategoryAccess'][$id] > time() - 86400) {
+      return;
+    }
+
+    $_SESSION['customCategoryAccess'][$id] = time();
+
+    $stmt = $db->prepare("insert into customCategoryAccess (id) values (:id)");
+    $stmt->bindValue(':id', $id);
+    $stmt->execute();
+  }
+
+  function saveCategory ($content) {
+    global $db;
+
+    $id = md5($content);
+
+    $stmt = $db->prepare("insert or ignore into customCategory (id, content) values (:id, :content)");
+    $stmt->bindValue(':id', $id, PDO::PARAM_STR);
+    $stmt->bindValue(':content', $content, PDO::PARAM_STR);
+    $result = $stmt->execute();
+
+    return $id;
+  }
+
+  function list ($options=[]) {
+    global $db;
+
     // the popularity column counts every acess with declining value over time,
     // it halves every year.
     $stmt = $db->prepare("select customCategory.id, customCategory.created, customCategory.content, t.accessCount, t.popularity, t.lastAccess from customCategory left join (select id, count(id) accessCount, sum(1/((julianday('2023-08-06 00:00:00') - julianday(ts))/365.25 + 1)) popularity, max(ts) lastAccess from customCategoryAccess group by id) t on customCategory.id=t.id order by popularity desc, created desc limit 25");
@@ -31,52 +76,35 @@ function ajax_customCategory ($param, $content) {
     $stmt->closeCursor();
     return $data;
   }
+}
 
-  if (isset($param['id'])) {
-    $stmt = $db->prepare("select content from customCategory where id=:id");
-    $stmt->bindValue(':id', $param['id'], PDO::PARAM_STR);
-    if ($stmt->execute()) {
-      $row = $stmt->fetch(PDO::FETCH_ASSOC);
-      $result = $row['content'];
-      $stmt->closeCursor();
-
-      customCategoryUpdateAccess($param['id']);
+$customCategoryRepository = new CustomCategoryRepository();
 
-      return $result;
-    }
+function ajax_customCategory ($param, $content) {
+  global $db;
+  global $customCategoryRepository;
 
-    return false;
+  if (!$db) {
+    return null;
   }
 
-  if (isset($param['action']) && $param['action'] === 'save') {
-    $id = md5($content);
-
-    $stmt = $db->prepare("insert or ignore into customCategory (id, content) values (:id, :content)");
-    $stmt->bindValue(':id', $id, PDO::PARAM_STR);
-    $stmt->bindValue(':content', $content, PDO::PARAM_STR);
-    $result = $stmt->execute();
-
-    customCategoryUpdateAccess($id);
-
-    return $result;
+  if (isset($param['action']) && $param['action'] === 'list') {
+    return $customCategoryRepository->list($param);
   }
-}
-
-function customCategoryUpdateAccess ($id) {
-  global $db;
 
-  if (!isset($_SESSION['customCategoryAccess'])) {
-    $_SESSION['customCategoryAccess'] = [];
-  }
+  if (isset($param['id'])) {
+    $category = $customCategoryRepository->getCategory($param['id']);
+    if ($category) {
+      $customCategoryRepository->recordAccess($param['id']);
+    }
 
-  // update access per session only once a day
-  if (array_key_exists($id, $_SESSION['customCategoryAccess']) && $_SESSION['customCategoryAccess'][$id] > time() - 86400) {
-    return;
+    return $category;
   }
 
-  $_SESSION['customCategoryAccess'][$id] = time();
+  if (isset($param['action']) && $param['action'] === 'save') {
+    $id = $customCategoryRepository->saveCategory($content);
+    $customCategoryRepository->recordAccess($id);
 
-  $stmt = $db->prepare("insert into customCategoryAccess (id) values (:id)");
-  $stmt->bindValue(':id', $id);
-  $stmt->execute();
+    return $id;
+  }
 }