FEM: Draft architecture of post data extraction with histogram example

src/Mod/Fem/App/FemPostObjectPyImp.cpp

@@ -29,6 +29,10 @@
 #include "FemPostObjectPy.h"
 #include "FemPostObjectPy.cpp"
 
+#ifdef BUILD_FEM_VTK_WRAPPER
+    #include <vtkDataSet.h>
+    #include <vtkPythonUtil.h>
+#endif //BUILD_FEM_VTK
 
 using namespace Fem;
 
@@ -55,6 +59,27 @@ PyObject* FemPostObjectPy::writeVTK(PyObject* args)
     Py_Return;
 }
 
+PyObject* FemPostObjectPy::getDataSet(PyObject* args)
+{
+#ifdef BUILD_FEM_VTK_WRAPPER
+    // we take no arguments
+    if (!PyArg_ParseTuple(args, "")) {
+        return nullptr;
+    }
+
+    // return python object for the dataset
+    auto dataset = getFemPostObjectPtr()->getDataSet();
+    if (dataset) {
+        PyObject* py_algorithm = vtkPythonUtil::GetObjectFromPointer(dataset);
+        return  Py::new_reference_to(py_algorithm);
+    }
+    return Py_None;
+#else
+    PyErr_SetString(PyExc_NotImplementedError, "VTK python wrapper not available");
+    Py_Return;
+#endif
+}
+
 PyObject* FemPostObjectPy::getCustomAttributes(const char* /*attr*/) const
 {
     return nullptr;