clarify default persistor_id (#2861)

Author: SYangster

nvflare/app_common/workflows/base_model_controller.py

@@ -38,15 +38,15 @@
 class BaseModelController(Controller, FLComponentWrapper, ABC):
     def __init__(
         self,
-        persistor_id="persistor",
+        persistor_id: str = AppConstants.DEFAULT_PERSISTOR_ID,
         ignore_result_error: bool = False,
         allow_empty_global_weights: bool = False,
         task_check_period: float = 0.5,
     ):
         """FLModel based controller.
 
         Args:
-            persistor_id (str, optional): ID of the persistor component. Defaults to "persistor".
+            persistor_id (str, optional): ID of the persistor component. Defaults to AppConstants.DEFAULT_PERSISTOR_ID ("persistor").
             ignore_result_error (bool, optional): whether this controller can proceed if client result has errors.
                 Defaults to False.
             allow_empty_global_weights (bool, optional): whether to allow empty global weights. Some pipelines can have

nvflare/app_common/workflows/model_controller.py

@@ -16,20 +16,21 @@
 from typing import Callable, List, Union
 
 from nvflare.app_common.abstract.fl_model import FLModel
+from nvflare.app_common.app_constant import AppConstants
 from nvflare.app_common.workflows.base_model_controller import BaseModelController
 
 
 class ModelController(BaseModelController, ABC):
     def __init__(
         self,
         *args,
-        persistor_id: str = "persistor",
+        persistor_id: str = AppConstants.DEFAULT_PERSISTOR_ID,
         **kwargs,
     ):
         """Model Controller API for FLModel-based Controller.
 
         Args:
-            persistor_id (str, optional): ID of the persistor component. Defaults to "".
+            persistor_id (str, optional): ID of the persistor component. Defaults to AppConstants.DEFAULT_PERSISTOR_ID ("persistor").
         """
         super().__init__(*args, persistor_id, **kwargs)