Fix nested flowsheet time domain construction

idaes/core/base/flowsheet_model.py

@@ -287,6 +287,31 @@ def _get_stream_table_contents(self, time_point=0):
         return self.stream_table(time_point)
 
     def _setup_dynamics(self):
+        def _create_time_domain():
+            if self.config.dynamic:
+                # Check if time_set has at least two points
+                if len(self.config.time_set) < 2:
+                    # Check if time_set is at default value
+                    if self.config.time_set == [0.0]:
+                        # If default, set default end point to be 1.0
+                        self.config.time_set = [0.0, 1.0]
+                    else:
+                        # Invalid user input, raise Exception
+                        raise DynamicError(
+                            "Flowsheet provided with invalid "
+                            "time_set attribute - must have at "
+                            "least two values (start and end)."
+                        )
+                # For dynamics, need a ContinuousSet
+                self._time = ContinuousSet(initialize=self.config.time_set)
+            else:
+                # For steady-state, use an ordered Set
+                self._time = pe.Set(initialize=self.config.time_set, ordered=True)
+            self._time_units = self.config.time_units
+
+            # Set time config argument as reference to time domain
+            self.config.time = self._time
+
         # Look for parent flowsheet
         fs = self.flowsheet()
 
@@ -342,35 +367,24 @@ def _setup_dynamics(self):
                     "{} was set as a dynamic flowsheet, but time domain "
                     "provided was not a ContinuousSet.".format(self.name)
                 )
+
+            if self.config.dynamic is False and not isinstance(
+                self.config.time, pe.Set
+            ):
+                raise DynamicError(
+                    "{} was set as a steady-state flowsheet, but time domain "
+                    "provided was not a Set.".format(self.name)
+                )
             add_object_reference(self, "_time", self.config.time)
             self._time_units = self.config.time_units
         else:
             # If no parent flowsheet, set up time domain
             if fs is None:
                 # Create time domain
-                if self.config.dynamic:
-                    # Check if time_set has at least two points
-                    if len(self.config.time_set) < 2:
-                        # Check if time_set is at default value
-                        if self.config.time_set == [0.0]:
-                            # If default, set default end point to be 1.0
-                            self.config.time_set = [0.0, 1.0]
-                        else:
-                            # Invalid user input, raise Exception
-                            raise DynamicError(
-                                "Flowsheet provided with invalid "
-                                "time_set attribute - must have at "
-                                "least two values (start and end)."
-                            )
-                    # For dynamics, need a ContinuousSet
-                    self._time = ContinuousSet(initialize=self.config.time_set)
-                else:
-                    # For steady-state, use an ordered Set
-                    self._time = pe.Set(initialize=self.config.time_set, ordered=True)
-                self._time_units = self.config.time_units
-
-                # Set time config argument as reference to time domain
-                self.config.time = self._time
+                _create_time_domain()
+            elif self.config.time_set is not None:
+                # Create time domain from config.time_set
+                _create_time_domain()
             else:
                 # Set time config argument to parent time
                 self.config.time = fs.time

idaes/core/base/tests/test_flowsheet_model.py

@@ -400,6 +400,39 @@ def test_dynamic_external_time(self):
         assert m.fs.sub.config.time is m.s
         assert m.fs.sub.time_units == units.minute
 
+    @pytest.mark.unit
+    def test_dynamic_nested_time(self):
+        m = ConcreteModel()
+        m.s1 = ContinuousSet(initialize=[4, 5])
+        m.s2 = ContinuousSet(initialize=[1,2,3])
+        m.fs = FlowsheetBlock(dynamic=True, time_units=units.s)
+        m.fs.sub = FlowsheetBlock(dynamic=True, time=m.s2, time_units=units.s)
+
+        assert m.fs.sub.config.dynamic is True
+        assert isinstance(m.fs.sub.time, ContinuousSet)
+        assert m.fs.sub.time_units == units.s
+
+    @pytest.mark.unit
+    def test_dynamic_nested_time_from_time_set(self):
+        m = ConcreteModel()
+        m.fs = FlowsheetBlock(dynamic=True, time_set = [1,2,3], time_units=units.s)
+        m.fs.sub = FlowsheetBlock(dynamic=True, time_set = [1, 2], time_units=units.s)
+
+        assert m.fs.sub.config.dynamic is True
+        assert isinstance(m.fs.sub.time, ContinuousSet)
+        assert m.fs.sub.time_units is units.s
+
+    @pytest.mark.unit
+    def test_dynamic_parent_time_indexed_ss_child(self):
+        m = ConcreteModel()
+        m.fs = FlowsheetBlock(dynamic=True, time_set = [1,2,3], time_units=units.s)
+        m.fs.sub = FlowsheetBlock(dynamic=False, time_set = [0, 1], time_units=units.dimensionless)
+
+        assert m.fs.sub.config.dynamic is False
+        assert isinstance(m.fs.sub.time, Set)
+        assert m.fs.sub.time_units == units.dimensionless
+
+
     @pytest.mark.unit
     def test_dynamic_external_time_invalid(self):
         m = ConcreteModel()