diff --git a/mod/data/lib.php b/mod/data/lib.php
index 88827767a6a..090263597ac 100644
--- a/mod/data/lib.php
+++ b/mod/data/lib.php
@@ -1208,14 +1208,13 @@ function data_print_template($template, $records, $data, $search='', $page=0, $r
     $cm = get_coursemodule_from_instance('data', $data->id);
     $context = context_module::instance($cm->id);
 
-    static $fields = NULL;
-    static $isteacher;
-    static $dataid = NULL;
+    static $fields = array();
+    static $dataid = null;
 
     if (empty($dataid)) {
         $dataid = $data->id;
     } else if ($dataid != $data->id) {
-        $fields = NULL;
+        $fields = array();
     }
 
     if (empty($fields)) {
@@ -1223,7 +1222,6 @@ function data_print_template($template, $records, $data, $search='', $page=0, $r
         foreach ($fieldrecords as $fieldrecord) {
             $fields[]= data_get_field($fieldrecord, $data);
         }
-        $isteacher = has_capability('mod/data:managetemplates', $context);
     }
 
     if (empty($records)) {
@@ -1698,14 +1696,13 @@ function data_print_preference_form($data, $perpage, $search, $sort='', $order='
         data_generate_default_template($data, 'asearchtemplate');
     }
 
-    static $fields = NULL;
-    static $isteacher;
-    static $dataid = NULL;
+    static $fields = array();
+    static $dataid = null;
 
     if (empty($dataid)) {
         $dataid = $data->id;
     } else if ($dataid != $data->id) {
-        $fields = NULL;
+        $fields = array();
     }
 
     if (empty($fields)) {
@@ -1713,8 +1710,6 @@ function data_print_preference_form($data, $perpage, $search, $sort='', $order='
         foreach ($fieldrecords as $fieldrecord) {
             $fields[]= data_get_field($fieldrecord, $data);
         }
-
-        $isteacher = has_capability('mod/data:managetemplates', $context);
     }
 
     // Replacing tags