[Boost-users] serialization: deserialization issue

25 Apr 2006

      I have a base class and some derived class.  Each class declare a  
serialize method.
each derived class begin its serialization method by:
         inArchive & BOOST_SERIALIZATION_BASE_OBJECT_NVP 
(FetchableMetadataObject);
to declare the inheritance relationship

then they serialize their own members:
         inArchive & BOOST_SERIALIZATION_NVP(xxxx);

I want the base class to declare a serialize as XML method that will  
return a string containing the serialized XML representation

std::string baseClass::SerializeAsXML() const
{
     return baseClass::saveToXML(this);
}

saveToXML is a static method on the baseClass
std::string baseClass::saveToXML(baseClass const* inObject)
{
     std::ostringstream returnValue;

     boost::archive::xml_oarchive archive(returnValue);
     archive << boost::serialization::make_nvp("root", inObject);

     return returnValue.str();
}

The serialization appear to work as when the object are printed for  
the unit test, i pass the xml serialized data and it contains the  
data that i expect it to contain.

The problems start when i want to reload the data into objects
I declared a constructor on the base class and on the derived class  
that accept the XML string and then rebuild the object using that  
string (is that a correct design decision?)

baseClass::MetadataObject(std::string const &serializedObject)
{
     baseClass::LoadFromXML(serializedObject, this);
}

derivedClass::MetadataObject(std::string const &serializedObject)
{
     baseClass::LoadFromXML(serializedObject, this);
}

LoadFromXML is a static method on the base class
void baseClass::LoadFromXML(std::string const &inXMLString, baseClass  
*inObject)
{
     std::istringstream inputStream (inXMLString);

     // open the archive
     assert(inputStream.good());
     boost::archive::xml_iarchive inputArchive(inputStream);

     // restore the schedule from the archive
     inputArchive >> boost::serialization::make_nvp("root", inObject);
}

The serialize method is not even called when de-serializing the  
object. So i assume i missed something:-)

Any help appreciated,
Olivier Destrebecq
olivierd@real.com