allow writer only to require data spec during run

spinn_utilities/data/utils_data_writer.py

@@ -146,7 +146,6 @@ def finish_run(self) -> None:
                 f"{self.__data._run_status}")
         self.__data._run_status = RunStatus.NOT_RUNNING
         self.__data._reset_status = ResetStatus.HAS_RUN
-        #self.__data._requires_data_generation = False
         self.__data._requires_mapping = False
 
     def _hard_reset(self) -> None:
@@ -213,6 +212,14 @@ def data_specification_loaded(self) -> None:
         """
         self.__data._requires_data_generation = False
 
+    def set_requires_data_generation(self) -> None:
+        """
+        Sets `requires_data_generation` to True.
+
+        Set to False after data is loaded
+        """
+        self.__data._requires_data_generation = True
+
     def request_stop(self) -> None:
         """
         Used to indicate a user has requested a stop.

unittests/data/test_utils_data.py

@@ -1030,15 +1030,20 @@ def test_requires(self):
         self.assertTrue(writer.get_requires_mapping())
         # Can not be changed during run
         with self.assertRaises(SimulatorRunningException):
-            writer.set_requires_data_generation()
+            UtilsDataView.set_requires_data_generation()
         with self.assertRaises(SimulatorRunningException):
             writer.set_requires_mapping()
         writer.data_specification_loaded()
         self.assertFalse(writer.get_requires_data_generation())
+        with self.assertRaises(SimulatorRunningException):
+            UtilsDataView.set_requires_data_generation()
+        writer.set_requires_data_generation()
+        self.assertTrue(writer.get_requires_data_generation())
         writer.finish_run()
 
+        # Stay as it was
+        self.assertTrue(writer.get_requires_data_generation())
         # False after run
-        self.assertFalse(writer.get_requires_data_generation())
         self.assertFalse(writer.get_requires_mapping())
 
         # Setting requires mapping sets both to True