C# App: Serializing collection of derived classes

[Shaul]

Hi,

My goal is to serialize a collection of type IList<AbstractC lass> which contains derived objects instances.
My domain object model is a bit complex so I've created a demmi one:

public abstract class ProductBase
{
    protected int _id;
    public int ID
    {
        get { return _id; }
        set { _id = value; }
    }
 
    protected string _name;
    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }
}
 
public class Coffee : ProductBase
{
    private string _type;
    public string Type
    {
        get { return _type; }
        set { _type = value; }
    }
 
    private bool _isDecaff;
    public bool IsDecaff
    {
        get { return _isDecaff; }
        set { _isDecaff = value; }
    }    
}
 
public class Tea : ProductBase
{
    private int _numOfSachets;
 
    public int NumOfSachets
    {
        get { return _numOfSachets; }
        set { _numOfSachets = value; }
    }
}
 
public class Store
{
    private List<ProductBase> _products = new List<ProductBase>();
    public List<ProductBase> Products
    {
        get { return _products; }
        set { _products = value; }
    }
}

Let's say the main program doe's the following:

static void Main(string[] args)
{
    Store store = new Store();
 
    Coffee prod1 = new Coffee();
    prod1.Type = "Espresso";    
 
    Tea prod2 = new Tea();
    prod1.NumOfSachets = 50;    
 
    store.Products.Add(prod1);
    store.Products.Add(prod2);
 
   //TODO: Represent store as XML document
 
}

I Want my XML document to look like this:
<Store>

<Products>

<Coffee type="Espresso" />

<Tea NumOfSachets="5 0" />

</Products>

</Store>

So far I've done serialization using the XmlSerializer but I can't seem to get it working in here. I've decorated all the attributes and elements of the base and derived classes, but the serialization fails until i add a

[XmlInclude(typeof(Coffee))]

to the ProductBase class (breaks oop).


Can someone please explain how it's suppose to be done?

Tnx in advance,
Shaul