FIX: if extra_data not None and type is 'str' than raised error. Fixed it.

devapp/dev_types.py

@@ -478,8 +478,8 @@ class ZteOnuDevice(OnuDevice):
         return '\n'.join(i for i in r if i)
 
     def register_device(self, extra_data: Dict):
-        if extra_data is None:
-            raise DeviceConfigurationError('You have not info in extra_data field, please fill it in JSON')
+        if not extra_data:
+            raise DeviceConfigurationError(_('You have not info in extra_data field, please fill it in JSON'))
         device = self.db_instance
         ip = None
         if device.ip_address:

devapp/locale/ru/LC_MESSAGES/django.po

@@ -636,6 +636,9 @@ msgstr "Не правильный логин или пароль для дост
 msgid "Process locked by another process"
 msgstr "Процесс занят другой задачей, подождите чуть и попробуйте ещё"
 
+msgid "You have not info in extra_data field, please fill it in JSON"
+msgstr "Не заполнено поле 'Техническая информация', обратитесь к администратору"
+
 #~ msgid "Device %(device_name)s is up"
 #~ msgstr "%(device_name)s в сети"
 

devapp/models.py

@@ -96,8 +96,8 @@ class Device(models.Model):
 
     def register_device(self):
         mng = self.get_manager_object()
-        if self.extra_data is None:
-            if self.parent_dev and self.parent_dev.extra_data is not None:
+        if not self.extra_data:
+            if self.parent_dev and self.parent_dev.extra_data:
                 return mng.register_device(self.parent_dev.extra_data)
         return mng.register_device(self.extra_data)