Base: Add 'getTypeIfDerivedFrom' member function to Type class

src/Base/Type.cpp

@@ -234,3 +234,16 @@ int Type::getNumTypes(void)
 {
   return typedata.size();
 }
+
+Type Type::getTypeIfDerivedFrom(const char* name , const Type parent, bool bLoadModule)
+{
+  if (bLoadModule)
+    importModule(name);
+
+  Type type = fromName(name);
+
+  if (type.isDerivedFrom(parent))
+    return type;
+  else
+    return Type::badType();
+}

src/Base/Type.h

@@ -101,6 +101,8 @@ public:
   bool isDerivedFrom(const Type type) const;
 
   static int getAllDerivedFrom(const Type type, std::vector<Type>& List);
+  /// Returns the given named type if is derived from parent type, otherwise return bad type
+  static Type getTypeIfDerivedFrom(const char* name , const Type parent, bool bLoadModule=false);
 
   static int getNumTypes(void);
 

src/Base/TypePyImp.cpp

@@ -216,26 +216,29 @@ PyObject* TypePy::createInstance (PyObject *args)
     if (!PyArg_ParseTuple(args, ""))
         return nullptr;
 
-    Base::BaseClass* base = static_cast<Base::BaseClass*>(getBaseTypePtr()->createInstance());
-    if (!base) {
-        Py_Return;
-    }
+    Py::String name(getBaseTypePtr()->getName());
+    Py::TupleN tuple(name);
 
-    return createPyObject(base);
+    return createInstanceByName(tuple.ptr());
 }
 
 PyObject* TypePy::createInstanceByName (PyObject *args)
 {
-    const char* type;
+    const char* name;
     PyObject* load = Py_False;
-    if (!PyArg_ParseTuple(args, "s|O!", &type, &PyBool_Type, &load))
+    if (!PyArg_ParseTuple(args, "s|O!", &name, &PyBool_Type, &load))
         return nullptr;
 
-    Base::BaseClass* base = static_cast<Base::BaseClass*>
-                                (Base::Type::createInstanceByName(type, PyObject_IsTrue(load) ? true : false));
-    if (!base) {
+    bool bLoad = PyObject_IsTrue(load) ? true : false;
+    Base::Type type = Base::Type::getTypeIfDerivedFrom(name, Base::BaseClass::getClassTypeId(), bLoad);
+    if (type.isBad())
         Py_Return;
-    }
+
+    void* typeInstance = type.createInstance();
+    if (!typeInstance)
+        Py_Return;
+
+    Base::BaseClass* base = static_cast<Base::BaseClass*>(typeInstance);
 
     return createPyObject(base);
 }