+ playing in sandbox

src/Mod/Sandbox/App/DocumentProtector.cpp

@@ -160,6 +160,25 @@ protected:
     const AbstractCallable& callable;
 };
 
+class CustomPurgeEvent : public AbstractCustomProtectorEvent
+{
+public:
+    CustomPurgeEvent(App::DocumentObject* o)
+      : obj(o)
+    {
+    }
+    ~CustomPurgeEvent()
+    {
+    }
+    void execute()
+    {
+        obj->purgeTouched();
+    }
+
+protected:
+    App::DocumentObject* obj;
+};
+
 class DocumentReceiver : public QObject
 {
 public:
@@ -324,3 +343,8 @@ void DocumentObjectProtector::execute(const AbstractCallable& call)
     DocumentReceiver::globalInstance()->postEventAndWait(new CustomCallableEvent(call));
 }
 
+void DocumentObjectProtector::purgeTouched()
+{
+    validate();
+    DocumentReceiver::globalInstance()->postEventAndWait(new CustomPurgeEvent(obj));
+}

src/Mod/Sandbox/App/DocumentProtector.h

@@ -127,6 +127,7 @@ public:
     App::DocumentObject* getObject() const;
     bool setProperty(const std::string& name, const App::Property& p);
     void execute(const AbstractCallable&);
+    void purgeTouched();
 
 private:
     void validate();

src/Mod/Sandbox/App/DocumentProtectorPy.cpp

@@ -162,6 +162,8 @@ void DocumentObjectProtectorPy::init_type()
     behaviors().supportRepr();
     behaviors().supportGetattr();
     behaviors().supportSetattr();
+
+    add_varargs_method("purgeTouched",&DocumentObjectProtectorPy::purgeTouched,"purgeTouched()");
 }
 
 DocumentObjectProtectorPy::DocumentObjectProtectorPy(App::DocumentObject *obj)
@@ -179,6 +181,13 @@ DocumentObjectProtectorPy::~DocumentObjectProtectorPy()
     delete _dp;
 }
 
+Py::Object DocumentObjectProtectorPy::getObject() const
+{
+    App::DocumentObject* obj = _dp->getObject();
+    PyObject* py = obj->getPyObject();
+    return Py::Object(py, true);
+}
+
 Py::Object DocumentObjectProtectorPy::repr()
 {
     std::string s;
@@ -201,10 +210,11 @@ Py::Object DocumentObjectProtectorPy::getattr(const char * attr)
         App::DocumentObject* obj = _dp->getObject();
         App::Property* prop = obj->getPropertyByName(attr);
         if (!prop) {
-            std::string s;
-            std::ostringstream s_out;
-            s_out << "No such attribute '" << attr << "'";
-            throw Py::AttributeError(s_out.str());
+            return Py::PythonExtension<DocumentObjectProtectorPy>::getattr(attr);
+            //std::string s;
+            //std::ostringstream s_out;
+            //s_out << "No such attribute '" << attr << "'";
+            //throw Py::AttributeError(s_out.str());
         }
 
         return Py::asObject(prop->getPyObject());
@@ -231,7 +241,18 @@ int DocumentObjectProtectorPy::setattr(const char * attr, const Py::Object & val
         Base::PyGILStateRelease unlock;
         std::auto_ptr<App::Property> copy(static_cast<App::Property*>
             (prop->getTypeId().createInstance()));
-        copy->setPyObject(value.ptr());
+        if (PyObject_TypeCheck(value.ptr(), DocumentObjectProtectorPy::type_object())) {
+            copy->setPyObject(static_cast<const DocumentObjectProtectorPy*>(value.ptr())->getObject().ptr());
+        }
+        else {
+            copy->setPyObject(value.ptr());
+        }
         return _dp->setProperty(attr, *copy) ? 0 : -1;
     }
 }
+
+Py::Object DocumentObjectProtectorPy::purgeTouched(const Py::Tuple&)
+{
+    _dp->purgeTouched();
+    return Py::None();
+}

src/Mod/Sandbox/App/DocumentProtectorPy.h

@@ -72,7 +72,9 @@ public:
 
     Py::Object repr();
     Py::Object getattr(const char *);
+    Py::Object getObject() const;
     int setattr(const char *, const Py::Object &);
+    Py::Object purgeTouched(const Py::Tuple&);
 
 private:
     DocumentObjectProtector* _dp;