Fem: Enable expression for the centrif constraint task panel

src/Mod/Fem/femobjects/constraint_centrif.py

@@ -31,6 +31,8 @@ __url__ = "https://www.freecad.org"
 
 from . import base_fempythonobject
 
+_PropHelper = base_fempythonobject._PropHelper
+
 
 class ConstraintCentrif(base_fempythonobject.BaseFemPythonObject):
     """
@@ -42,18 +44,36 @@ class ConstraintCentrif(base_fempythonobject.BaseFemPythonObject):
     def __init__(self, obj):
         super().__init__(obj)
 
-        obj.addProperty(
-            "App::PropertyFrequency",
-            "RotationFrequency",
-            "Constraint CENTRIF",
-            "set rotation frequency f<sub>rot",
-        )
-        obj.setPropertyStatus("RotationFrequency", "LockDynamic")
+        for prop in self._get_properties():
+            prop.add_to_object(obj)
 
-        obj.addProperty(
-            "App::PropertyLinkSubList",
-            "RotationAxis",
-            "Constraint CENTRIF",
-            "set line as axis of rotation",
+    def _get_properties(self):
+        prop = []
+
+        prop.append(
+            _PropHelper(
+                type="App::PropertyFrequency",
+                name="RotationFrequency",
+                group="Constraint Centrif",
+                doc="Set rotation frequency",
+                value="0 1/s",
+            )
         )
-        obj.setPropertyStatus("RotationAxis", "LockDynamic")
+        prop.append(
+            _PropHelper(
+                type="App::PropertyLinkSubListGlobal",
+                name="RotationAxis",
+                group="Constraint Centrif",
+                doc="Set line as axis of rotation",
+                value=[],
+            )
+        )
+
+        return prop
+
+    def onDocumentRestored(self, obj):
+        # update old project with new properties
+        for prop in self._get_properties():
+            if prop.name == "RotationAxis":
+                # change RotationAxis to App::PropertyLinkSubListGlobal
+                prop.handle_change_type(obj, old_type="App::PropertyLinkSubList")