Design Patterns discussion

["Chris Finlayson" <cfinlayson AT vls-inc.com>]

Hi all:

I have a very basic question - I may be missing something here.

In following design patterns, one has interfaces and abstract classes all
over the place - how does one "properly" go about serializing/deserializing
objects whose exact class is unknown?

Take a simple example where one is serializing out a concrete strategy
selected at run-time, and then wants to
read it back in at a later point:

----------begin some program--------------------
ISortStrategy oStrategy = SortFactory::Create("QuickSort");
//....
//doing some with oStrategy
//.....
oStrategy.serialize(somestream) //The concrete QuickSort strategy is
serialized out

//now I want to read it back in..what do I do hear?

//I could do something like:
oStrategy = SortFactory::Deserialize(somestream);

--------------end some program---------------

I would have each of my concrete sort strategies write out some sort of
identifier prior to writing the data, so the resultant serialized data would
look something like:

QuickSort
data....

Then, SortFactory's "Deserialize" method would look something like:

Deserialize(somestream)
{
        string objecttype = .....   //read in object type from stream
        ISortStrategy oStrategy = SortFactory::Create(objecttype)
        oStrategy.deserialize(somestream);
}

Is there a better way to do this?

Thanks! --Chris.