Question

I have two app. The one use XAF (devexpress framework), the second use asp.net mvc.
My bussines classes is created in XAF app. Both use same database.
My classes in XAF:

    public class BaseClass:XPObject
    {
    // some fields
    }

    // This attribute mean that all fields will be stored in BaseClass table
    [MapInheritance(InheritanceType.ParentTable] 
    public class Class1:BaseClass
    {
    // some fields
    }

   // This attribute mean that all fields will be stored in BaseClass table
    [MapInheritance(InheritanceType.ParentTable] 
    public class Class2:BaseClass
    {
    // some fields
    }

In a DB we have one table: BaseClass with fields from BaseClass, Class1.

There are such moment: XAF adding own field called ObjectType (it’s FK to XPObjectType table which XAF create automatically).
In result we have in a DB:

BaseClass:

ID      some_fields_from_BaseClass      some_fields_from_Class1      ObjectType
1             some_values                    some_values                1

XPObjectType:
ID                TypeName                    AssemblyName
1             TestApp.Module.BO.Class1       TestApp.Module 

Now, I wrote in the ASP.NET MVC app:

Database.BaseClasses.Where( ...some predicate...).ToList();

This query return me collection of BaseClass. But, I want that query return me derived types (Class1 or Class2 or Class 3, for example).
How can I do this?

PS. I can’t use IsDiscriminator attribute because it’s FK and I don’t want to diplicate objects (Class1, class2 in asp.net mvc app).

Answer 1

Try this one:

public List<T> GetData<T>(Func<T,bool> fn) where T :BaseClass
    {
        if (typeof(T) == typeof(BaseClass))
        {
            List<T> res = null; // Fillout from database
            var r = res.Where(fn).Select(o => (BaseClass)o).ToList();
        }
        else
        {
            throw new Exception("Invalid type, this service support only BaseClasses");
        }

        return null;
    }