Question

Consider the below:

public class DependencyA {}
public class DependencyB {}
public class DependencyC {}
public class DependencyD {}

public class Service1
{
    public Service1(DependencyA a, DependencyB b, DependencyC c, DependencyD d) { ... }
}
public class Service2
{
    public Service2(DependencyA a, DependencyB b, DependencyC c, DependencyD d) { ... }
}
public class Service3
{
    public Service3(DependencyA a, DependencyB b, DependencyC c, DependencyD d) { ... }
}

I am finding that many of my services are dependent on multiple common components, and am thinking of implementing a catch all solution like below (all wired up through Windsor) to save repetition of code in the Service constructors.

public class DependencyContainer
{
    public DependencyA A { get; set; }
    public DependencyB B { get; set; }
    public DependencyC C { get; set; }
    public DependencyD D { get; set; }
}

public class Service1
{
    public Service1 (DependencyContainer container) { ... }
}

Alternatively I could create a ServiceBase class.

public class ServiceBase
{
    public DependancyA A { get; set; }
    public DependancyB B { get; set; }
    public DependancyC C { get; set; }
    public DependancyD D { get; set; }
}

public class Service1 : ServiceBase {}

The real question is does this highlight a wider design issue in the services?

Perhaps I am taking DI too far, but these are all genuine dependencies.

If so how do I code around this?
If not is the proposed solution a valid way to achieve this goal?

Answer 1

Having too many dependencies on your services might show that your service is doing too many things. In other words its probably violating Single Responsibility Principle.