C# .NET Design Pattern issue

.net, c#, design-patterns

Solution

GetById isn't defined in the interface

I would make an

public interface IBaseRepository<T> where T : BaseEntitiy {
 T GetById<T>(int id);
}

Then `BaseClass` implements `IBaseRepository<T>`

and `IFooRepository` inherits from `IBaseRepository<Foo>`

EDIT :

A full example, similar to @Olivier J-D one, with idea (maybe wrong), that GetOrderedObject may be same for all your entities.

public abstract class BaseEntity
{
    public override abstract String ToString();
}

//all generic methods
public interface IRepositoryBase<T>
    where T : BaseEntity, new()
{
    T GetById(int id);
    IList<T> GetOrderedObjects();

}

//all methods specific to foo, which can't be in a generic class
public interface IFooRepository :IRepositoryBase<Foo>
{
    void Update(Foo model);
}

//implementation of generic methods
public abstract class BaseClass<T> : IRepositoryBase<T>
    where T : BaseEntity, new() // ===> Add new() constraint here
{
    public T GetById(int id)
    {
        return new T();
    }
    public IList<T> GetOrderedObjects() {
        var obj = this.GetById(5);

        //Dummy Code
        return new List<Foo>();
        //
    }
}

//implementation of Foo specific methods
public class FooRepository : BaseClass<Foo>, IFooRepository
{
    public void Update(Foo model) {
    //bla bla
    }
}

Problem

I'm trying to implement the best code re-usability. The problem is that I can't access the base method located in the Base Abstract class form the Main Program through the repository. If you go through the example below you will see a sample code of my situation. So my question is how can I access methods located in the base abstract class from the main program. Classes/Interfaces ``` public abstract class BaseEntity { public override abstract String ToString(); } public abstract class BaseClass<T> where T : BaseEntity { public T GetById(int id) { //Dummy Code return new T(); // } } public interface IFooRepository { IList<Foo> GetOrderedObjects(); } public interface FooRepository : BaseClass<Foo>, IFooRepository { public IList<Foo> GetOrderedObjects() { //GetById method is accessible from the repository - Fine var obj = this.GetById(5); //Dummy Code return new List<Foo>(); // } } ``` //Main App ``` public class void Main() { private IFooRepository _fooRepository; public void ProgramStartsHere() { //This is ok. var list = _fooRepository.GetOrderedObjects(); //Problem is here - GetById method is not accessible from the main program through the FooRepository var obj = _fooRepository.GetById(10); } } ```

Original source