CODEWITHSUNDEEP
c#.net
Mo09890
Mo09890

Reputation: 174

How to handle dependencies between business objects

Apologies if this has been asked before, I can't find a similar question so I can only assume my terminology is wrong!

Anyway I'm wondering how to handle dependencies between business layer objects. Say I have two business objects:

A Wheel Service

public class WheelService : IWheelService
{
    private IWheelRepository Repository { get; set; }

    public WheelService(IWheelRepository repository)
    {
        this.Repository = repository;
    }

    public Wheel Get(int id) { ... }
}

And a Car Service

public class CarService : ICarService
{
    private ICarRepository Repository { get; set; }

    public CarService(ICarRepository repository)
    {
        this.Repository = repository;
    }

    public void Create(Car newCar)
    {
        // I need to access functions from the WheelService here
    }
}

What sort of architecture would you use that would all me to call methods of one business object from another in a loosely coupled way that would also fit well with TDD?

Upvotes: 0

Views: 110

Answers (2)

oleksii
oleksii

Reputation: 35925

You can also use a Builder pattern, which will be useful if you have many dependencies

public class CarService : ICarService
{
    private ICarRepository Repository { get; set; }
    private IWheelService WheelService { get; set; }

    public CarService(ICarRepository repository)
    {
        this.Repository = repository;
    }

    public ICarService WithWheelService(IWheelService service)
    {
        // do arguments check
        if(service == null) throw ...;

        WheelService = service;
        return this;
    }
    public Car Build()
    {
        return new Car(WheelService, ...);        
    }
}

Here is the usage

ICarService carService = new CarService();
IWheelService wheelService = new WheelService();
...    
carService.WithWheelService(wheelService)
          .WithSomethingElse(somethingElse)
          .WithLights(brightLights)
          .UsingMainColour(selectedColour);
var car = carService.Build()

See these lines

ICarService carService = new CarService();
IWheelService wheelService = new WheelService();

This is where you can use IoC container to resolve the needed classes.

Upvotes: 0

Peter
Peter

Reputation: 27944

Just add them the same way you add your repository dependence in your constructor:

public CarService(ICarRepository repository, IWheelService wheelservice)
{
    ...
}

Upvotes: 2

Related Questions