Add MeshedRegion.is_empty() query handling retro for faces

Author: PProfizi

src/ansys/dpf/core/meshed_region.py

@@ -35,7 +35,7 @@
 
 from ansys.dpf.core import field, property_field, scoping, server as server_module
 from ansys.dpf.core.cache import class_handling_cache
-from ansys.dpf.core.check_version import server_meet_version, version_requires
+from ansys.dpf.core.check_version import meets_version, server_meet_version, version_requires
 from ansys.dpf.core.common import (
     locations,
     nodal_properties,
@@ -701,3 +701,15 @@ def field_of_properties(self, property_name):
                     # Not sure we go through here since the only datatype not int is coordinates,
                     # which is already dealt with previously.
                     return field.Field(server=self._server, field=field_out)
+
+    def is_empty(self) -> bool:
+        """Whether the mesh is empty.
+
+        A mesh is considered empty when it has zero element, zero face, and zero node.
+        """
+        no_faces = True
+        if meets_version(self._server, "7.0"):
+            no_faces = self.faces.n_faces == 0
+        no_elements = self.elements.n_elements == 0
+        no_nodes = self.nodes.n_nodes == 0
+        return no_nodes and no_faces and no_elements

src/ansys/dpf/core/plotter.py

@@ -895,7 +895,7 @@ def plot_contour(
             mesh = meshed_region
         else:
             mesh = self._mesh
-        if mesh.elements.n_elements == 0 and mesh.nodes.n_nodes == 0 and mesh.faces.n_faces == 0:
+        if mesh.is_empty():
             raise dpf_errors.EmptyMeshPlottingError
 
         # get mesh scoping