diff --git a/src/Tpl.php b/src/Tpl.php
index db81899..30a13e1 100644
--- a/src/Tpl.php
+++ b/src/Tpl.php
@@ -262,6 +262,44 @@ class Tpl {
     $_SESSION['messages'][] = $message;
   }
 
+  /**
+   * Get errors
+   * @return array<string>
+   */
+  public static function get_errors() {
+    if(isset($_SESSION['errors']) && is_array($_SESSION['errors']))
+        return $_SESSION['errors'];
+    return array();
+  }
+
+  /**
+   * Get messages
+   * @return array<string>
+   */
+  public static function get_messages() {
+      if(isset($_SESSION['messages']) && is_array($_SESSION['messages']))
+          return $_SESSION['messages'];
+      return array();
+  }
+
+  /**
+   * Purge messages
+   * @return void
+   */
+  public static function purge_errors() {
+      if(isset($_SESSION['errors']))
+          unset($_SESSION['errors']);
+  }
+
+  /**
+   * Purge messages
+   * @return void
+   */
+  public static function purge_messages() {
+      if(isset($_SESSION['messages']))
+          unset($_SESSION['messages']);
+  }
+
   /**
    * Register CSS file(s) to load on next displayed page
    * @param string|array<string> $args CSS files to load
@@ -329,8 +367,8 @@ class Tpl {
     self :: add_js_file(App::get('templates.included_js_files', array(), 'array'));
 
     // Messages
-    self :: assign('errors', (isset($_SESSION['errors'])?$_SESSION['errors']:array()));
-    self :: assign('messages', (isset($_SESSION['messages'])?$_SESSION['messages']:array()));
+    self :: assign('errors', self :: get_errors());
+    self :: assign('messages', self :: get_messages());
 
     // Files inclusions
     self :: assign('css', self :: $css_files);
@@ -388,8 +426,8 @@ class Tpl {
         Log :: fatal(I18n::_("An error occurred while displaying this page."));
       return;
     }
-    unset($_SESSION['errors']);
-    unset($_SESSION['messages']);
+    self :: purge_errors();
+    self :: purge_messages();
     Hook :: trigger('after_displaying_template');
     $sentry_span->finish();
   }
@@ -408,14 +446,14 @@ class Tpl {
     elseif (isset($data['success']) && !$data['success'] && http_response_code() == 200)
       http_response_code(400);
 
-    if (isset($_SESSION['messages']) && !empty($_SESSION['messages'])) {
-      $data['messages'] = $_SESSION['messages'];
-      unset($_SESSION['messages']);
-    }
-    if (isset($_SESSION['errors']) && !empty($_SESSION['errors'])) {
-      $data['errors'] = $_SESSION['errors'];
-      unset($_SESSION['errors']);
-    }
+    $data['messages'] = self :: get_messages();
+    if (!$data['messages']) unset($data['messages']);
+    self :: purge_messages();
+
+    $data['errors'] = self :: get_errors();
+    if (!$data['errors']) unset($data['errors']);
+    self :: purge_errors();
+
     if (self :: $_debug_ajax)
       Log :: debug("AJAX Response : ".vardump($data));
     header('Content-Type: application/json');