diff --git a/File.class.php b/File.class.php
index a7d4f05..e430728 100644
--- a/File.class.php
+++ b/File.class.php
@@ -5,25 +5,25 @@ abstract class File
     public $path;
     public $filename;
     /**
-     * @param array|string $data
+     * @param array|string|null $data
      * @return Image
      * @throws ErrorException
      */
-    public static function getInstance($data)
+    public static function getInstance($data = null)
     {
-        if (is_null($data) || $data == '') {
-            throw new ErrorException('Empty data for File::getInstance().');
-        }
-        if (!is_array($data)) {
+        $instance = new static;
+        if (!(is_null($data) && $data == '')) {
+            if (!is_array($data)) {
             $data = json_decode($data, true);
-            if (json_last_error() != JSON_ERROR_NONE) {
-                throw new ErrorException('Unable to convert json-string to array.');
+                if (json_last_error() != JSON_ERROR_NONE) {
+                    //TODO: decrease warning level
+                    throw new ErrorException('Unable to convert json-string to array. Data ' . print_r($data, true));
+                }
             }
-        }
-        $instance = new static($data);
-        foreach ($data as $attribute_name => $attribute_value) {
-            if (property_exists($instance, $attribute_name)) {
-                $instance->{$attribute_name} = $attribute_value;
+            foreach ($data as $attribute_name => $attribute_value) {
+                if (property_exists($instance, $attribute_name)) {
+                    $instance->{$attribute_name} = $attribute_value;
+                }
             }
         }
         return $instance;