update lấy features từ ảnh upload

models/common.php

@@ -181,4 +181,14 @@ class common extends \yii\db\ActiveRecord {
         ]));
     }
 
+    public static function generateRandomString($length = 10) {
+        $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
+        $charactersLength = strlen($characters);
+        $randomString = '';
+        for ($i = 0; $i < $length; $i++) {
+            $randomString .= $characters[rand(0, $charactersLength - 1)];
+        }
+        return $randomString;
+    }
+
 }