Fix bug where existing meshes were not deleted when switching representations.

src/blenderbim/blenderbim/core/geometry.py

@@ -77,14 +77,20 @@ def switch_representation(
     geometry, obj=None, representation=None, should_reload=True, enable_dynamic_voids=True, is_global=True
 ):
     representation = geometry.resolve_mapped_representation(representation)
-    data = geometry.get_representation_data(representation)
+    existing_data = geometry.get_representation_data(representation)
 
-    if not data or should_reload:
+    if should_reload or not existing_data:
         data = geometry.import_representation(obj, representation, enable_dynamic_voids=enable_dynamic_voids)
         geometry.rename_object(data, geometry.get_representation_name(representation))
         geometry.link(representation, data)
+    else:
+        data = existing_data
 
     geometry.change_object_data(obj, data, is_global=is_global)
+
+    if should_reload and existing_data:
+        geometry.delete_data(existing_data)
+
     geometry.clear_modifiers(obj)
 
     if enable_dynamic_voids and geometry.is_body_representation(representation):

src/blenderbim/blenderbim/core/tool.py

@@ -74,6 +74,7 @@ class Geometry:
     def change_object_data(cls, obj, data, is_global=False): pass
     def clear_modifiers(cls, obj): pass
     def create_dynamic_voids(cls, obj): pass
+    def delete_data(cls, data): pass
     def does_object_have_mesh_with_faces(cls, obj): pass
     def duplicate_object_data(cls, obj): pass
     def get_cartesian_point_coordinate_offset(cls, obj): pass

src/blenderbim/blenderbim/tool/geometry.py

@@ -52,6 +52,11 @@ class Geometry(blenderbim.core.tool.Geometry):
             modifier.solver = "EXACT"
             modifier.use_self = True
 
+
+    @classmethod
+    def delete_data(cls, data):
+        bpy.data.meshes.remove(data)
+
     @classmethod
     def does_object_have_mesh_with_faces(cls, obj):
         return bool(isinstance(obj.data, bpy.types.Mesh) and len(obj.data.polygons))

src/blenderbim/test/core/test_geometry.py

@@ -179,9 +179,9 @@ class TestAddRepresentation:
 
 
 class TestSwitchRepresentation:
-    def test_switching_to_a_freshly_reloaded_representation(self, geometry):
+    def test_switching_to_a_freshly_loaded_representation(self, geometry):
         geometry.resolve_mapped_representation("mapped_rep").should_be_called().will_return("representation")
-        geometry.get_representation_data("representation").should_be_called().will_return("data")
+        geometry.get_representation_data("representation").should_be_called().will_return(None)
         geometry.import_representation(
             "obj", "representation", enable_dynamic_voids=True
         ).should_be_called().will_return("new_data")
@@ -201,6 +201,29 @@ class TestSwitchRepresentation:
             is_global=True,
         )
 
+    def test_switching_to_a_reloaded_representation_and_deleting_the_existing_data(self, geometry):
+        geometry.resolve_mapped_representation("mapped_rep").should_be_called().will_return("representation")
+        geometry.get_representation_data("representation").should_be_called().will_return("existing_data")
+        geometry.import_representation(
+            "obj", "representation", enable_dynamic_voids=True
+        ).should_be_called().will_return("new_data")
+        geometry.get_representation_name("representation").should_be_called().will_return("name")
+        geometry.rename_object("new_data", "name").should_be_called()
+        geometry.link("representation", "new_data").should_be_called()
+        geometry.change_object_data("obj", "new_data", is_global=True).should_be_called()
+        geometry.delete_data("existing_data").should_be_called()
+        geometry.clear_modifiers("obj").should_be_called()
+        geometry.is_body_representation("representation").should_be_called().will_return(True)
+        geometry.create_dynamic_voids("obj").should_be_called()
+        subject.switch_representation(
+            geometry,
+            obj="obj",
+            representation="mapped_rep",
+            should_reload=True,
+            enable_dynamic_voids=True,
+            is_global=True,
+        )
+
     def test_switching_to_an_existing_representation(self, geometry):
         geometry.resolve_mapped_representation("mapped_rep").should_be_called().will_return("representation")
         geometry.get_representation_data("representation").should_be_called().will_return("data")

src/blenderbim/test/tool/test_geometry.py

@@ -82,6 +82,13 @@ class TestCreateDynamicVoids(NewFile):
         assert modifier.use_self is True
 
 
+class TestDeleteData(NewFile):
+    def test_run(self):
+        data = bpy.data.meshes.new("Mesh")
+        subject.delete_data(data)
+        assert not bpy.data.meshes.get("Mesh")
+
+
 class TestDoesObjectHaveMeshWithFaces(NewFile):
     def test_empties_return_false(self):
         obj = bpy.data.objects.new("Object", None)