Change new workflow algorithm to use child algorithms

Previously it was calling other algorithms directly which will not play
well with the history

Re #32125

Framework/PythonInterface/plugins/algorithms/WorkflowAlgorithms/ReflectometryISISPreprocess.py

@@ -8,7 +8,6 @@
 from mantid.api import (AlgorithmFactory, DataProcessorAlgorithm, MatrixWorkspaceProperty, MatrixWorkspace, WorkspaceGroup)
 from mantid.kernel import (CompositeValidator, StringArrayLengthValidator, StringArrayMandatoryValidator,
                            StringArrayProperty, Direction)
-from mantid.simpleapi import LoadEventNexus, LoadNexus
 
 
 class ReflectometryISISPreprocess(DataProcessorAlgorithm):
@@ -66,14 +65,17 @@ class ReflectometryISISPreprocess(DataProcessorAlgorithm):
         workspace otherwise. Transmission runs are always loaded as histogram workspaces."""
         event_mode = self.getProperty(self._EVENT_MODE).value
         if event_mode:
-            alg = LoadEventNexus(Filename=run, LoadMonitors=True, StoreInADS=False)
-            ws = alg.OutputWorkspace
+            alg = self.createChildAlgorithm('LoadEventNexus', Filename=run, LoadMonitors=True)
+            alg.execute()
+            ws = alg.getProperty('OutputWorkspace').value
             # TODO
             # monitors = alg.MonitorWorkspace
             self._validate_event_ws(ws)
             self.log().information('Loaded event workspace')
         else:
-            ws = LoadNexus(Filename=run, StoreInADS=False)
+            alg = self.createChildAlgorithm('LoadNexus', Filename=run)
+            alg.execute()
+            ws = alg.getProperty('OutputWorkspace').value
             self.log().information('Loaded workspace ')
         return ws
 

Framework/PythonInterface/test/python/plugins/algorithms/WorkflowAlgorithms/ReflectometryISISPreprocessTest.py

@@ -5,17 +5,18 @@
 #   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
 # SPDX - License - Identifier: GPL - 3.0 +
 import unittest
-from unittest import mock
 
 from mantid.api import IEventWorkspace, MatrixWorkspace, WorkspaceGroup
-from mantid.simpleapi import CreateSampleWorkspace, ReflectometryISISPreprocess
+from mantid.simpleapi import CreateSampleWorkspace
+from plugins.algorithms.WorkflowAlgorithms.ReflectometryISISPreprocess import ReflectometryISISPreprocess
+from testhelpers import create_algorithm
 
 
 class ReflectometryISISPreprocessTest(unittest.TestCase):
     def test_input_run_is_loaded_histo_mode_by_default(self):
         args = {'InputRunList': '13460',
                 "OutputWorkspace": "ws"}
-        output_ws = ReflectometryISISPreprocess(**args)
+        output_ws = self._run_test(args)
         self.assertIsInstance(output_ws, MatrixWorkspace)
         self.assertEqual("Workspace2D", output_ws.id())
 
@@ -23,7 +24,7 @@ class ReflectometryISISPreprocessTest(unittest.TestCase):
         args = {'InputRunList': '13460',
                 "EventMode": False,
                 "OutputWorkspace": "ws"}
-        output_ws = ReflectometryISISPreprocess(**args)
+        output_ws = self._run_test(args)
         self.assertIsInstance(output_ws, MatrixWorkspace)
         self.assertEqual("Workspace2D", output_ws.id())
 
@@ -31,30 +32,28 @@ class ReflectometryISISPreprocessTest(unittest.TestCase):
         args = {'InputRunList': '13460',
                 "EventMode": True,
                 "OutputWorkspace": "ws"}
-        output_ws = ReflectometryISISPreprocess(**args)
+        output_ws = self._run_test(args)
         self.assertIsInstance(output_ws, IEventWorkspace)
 
-    @mock.patch("ReflectometryISISPreprocess.LoadEventNexus")
-    def test_validation_of_event_workspaces_without_proton_charge_throws(self, mocked_loader):
-        args = {'InputRunList': '13460',
-                "EventMode": True,
-                "OutputWorkspace": "ws"}
-
+    def test_validation_of_event_workspaces_without_proton_charge_throws(self):
         ws = CreateSampleWorkspace()
-        mocked_loader.return_value.OutputWorkspace = ws
-        with self.assertRaisesRegex(RuntimeError, "proton_charge"):
-            ReflectometryISISPreprocess(**args)
 
-    @mock.patch("ReflectometryISISPreprocess.LoadEventNexus")
-    def test_validation_of_event_workspace_group_throws(self, mocked_loader):
-        args = {'InputRunList': '13460',
-                "EventMode": True,
-                "OutputWorkspace": "ws"}
+        with self.assertRaisesRegex(RuntimeError, "proton_charge"):
+            ReflectometryISISPreprocess._validate_event_ws(ws)
 
+    def test_validation_of_event_workspace_group_throws(self):
         ws = WorkspaceGroup()
-        mocked_loader.return_value.OutputWorkspace = ws
+
         with self.assertRaisesRegex(RuntimeError, "Workspace Groups"):
-            ReflectometryISISPreprocess(**args)
+            ReflectometryISISPreprocess._validate_event_ws(ws)
+
+    def _run_test(self, args):
+        alg = create_algorithm('ReflectometryISISPreprocess', **args)
+        alg.setChild(True)
+        alg.setRethrows(True)
+        alg.execute()
+        output_ws = alg.getProperty('OutputWorkspace').value
+        return output_ws
 
 
 if __name__ == '__main__':