fix(retro): fix retro-compatibility with pyvista<0.46.0 (#2539)

Author: PProfizi

src/ansys/dpf/core/vtk_helper.py

@@ -185,18 +185,22 @@ def dpf_mesh_to_vtk_op(mesh, nodes=None, as_linear=True):
     celltypes_pv = mesh_to_pyvista.outputs.cell_types()
     if VTK9:
         grid = pv.UnstructuredGrid(cells_pv, celltypes_pv, nodes_pv)
-        # setattr(grid, "_dpf_cache_op", [cells_pv, celltypes_pv, nodes_pv])
-        pv.set_new_attribute(
-            obj=grid, name="_dpf_cache_op", value=[cells_pv, celltypes_pv, nodes_pv]
-        )
+        if hasattr(pv, "set_new_attribute"):  # For pyvista >=0.46.0
+            pv.set_new_attribute(
+                obj=grid, name="_dpf_cache_op", value=[cells_pv, celltypes_pv, nodes_pv]
+            )
+        else:  # For pyvista <0.46.0  # pragma: nocover
+            setattr(grid, "_dpf_cache_op", [cells_pv, celltypes_pv, nodes_pv])
         return grid
     else:
         offsets_pv = mesh_to_pyvista.outputs.offsets()
         grid = pv.UnstructuredGrid(offsets_pv, cells_pv, celltypes_pv, nodes_pv)
-        # setattr(grid, "_dpf_cache_op", [cells_pv, celltypes_pv, nodes_pv, offsets_pv])
-        pv.set_new_attribute(
-            obj=grid, name="_dpf_cache_op", value=[cells_pv, celltypes_pv, nodes_pv, offsets_pv]
-        )
+        if hasattr(pv, "set_new_attribute"):  # For pyvista >=0.46.0
+            pv.set_new_attribute(
+                obj=grid, name="_dpf_cache_op", value=[cells_pv, celltypes_pv, nodes_pv, offsets_pv]
+            )
+        else:  # For pyvista <0.46.0  # pragma: nocover
+            setattr(grid, "_dpf_cache_op", [cells_pv, celltypes_pv, nodes_pv, offsets_pv])
         return grid
 
 
@@ -356,11 +360,12 @@ def compute_offset():
 
         # Quick fix required to hold onto the data as PyVista does not make a copy.
         # All of those now return DPFArrays
-        # setattr(grid, "_dpf_cache", [node_coordinates, coordinates_field])
-        pv.set_new_attribute(
-            obj=grid, name="_dpf_cache", value=[node_coordinates, coordinates_field]
-        )
-
+        if hasattr(pv, "set_new_attribute"):  # For pyvista >=0.46.0
+            pv.set_new_attribute(
+                obj=grid, name="_dpf_cache_op", value=[node_coordinates, coordinates_field]
+            )
+        else:  # For pyvista <0.46.0  # pragma: nocover
+            setattr(grid, "_dpf_cache_op", [node_coordinates, coordinates_field])
         return grid
 
     # might be computed when checking for VTK quadratic bug