Interfaces for fluent ordered constructor

Question

iam creating an interface for a fluent ordered constructor and i have wrote this code:

public interface IMyObjectFactory: IObjectWithProperty
{
  int objectId { get; set; }
  IObjectWithProperty WithObjectId(int id);
}

public interface IObjectWithProperty
{
  IObjectWithProperty WithObjectId(int id);
  MyObject Create();
}

the second interface is need to enforce order in constructor method

the impl is this:

public class MyObjectFactory: IMyObjectFactory
{
    public int objectId { get; set; }
    private MyObjectFactory() { }
    public static IObjectWithProperty BeginCreation()
    {
        return new ObjectFactory();
    }
    public IObjectWithProperty WithObjectId(int id)
    {
        objectId = id;
        return this;
    }

    public MyObject Create()
    {
        return new MyObject(this);
    }
}

And this is my object:

public class MyObject
{
  public int Id { get; set; }
  public MyObject(IMyObjectFactory factory)
  {
    this.Id = factory.objectId;
  }
}

so I can write

MyObject mo = MyObjectFactory.BeginCreation().WithObjectId(1).Create();

but:

• I have to define property both in interface and impl of the constructor and don't like much
• the static BeginCreation method has no interface
• I have to set public the impl property while i want it internal
• in the interface i get this warning: Warning 7 'FunzIA.DL.Factory.Interfaces.IMyObjectFactory.WithObjectId(int)' hides inherited member 'FunzIA.DL.Factory.Interfaces.IObjectWithProperty.WithObjectId(int)'. Use the new keyword if hiding was intended.

but is not a new method and i need the second interface to enforce order

Any suggestion? Thanks

Answer 1

I do it in this way:

• simply don't want to let class constructor to be visible, i want only the factory to be accessible

public interface IMyObjectFactory: IObjectWithProperty
{
  int objectId { get; set; }
}

public interface IObjectWithProperty
{
  IObjectWithProperty WithObjectId(int id);
  MyObject Create();
}

public class MyObjectFactory: IMyObjectFactory
{
  public int objectId;
  private MyObjectFactory() { }

  public static IObjectWithProperty BeginCreation()
  {
    return new MyObjectFactory();
  }

  public IObjectWithProperty WithObjectId(int id)
  {
    objectId = id;
    return this;
  }

  public MyObject Create()
  {
    return new MyObject(this);
  }
}

public class MyObject
{
  public int Id { get; set; }
  public MyObject(IMyObjectFactory factory)
  {
    this.Id = factory.objectId;
  }
}