Always Valid Entity and Constructor Injection

Question

Giving the following sample:

class Customer
{ 
    ICustomerRepository repository;

    private string name;

    public Customer(string name, ICustomerRepository repository)
    {        
        Name = name;
        this.repository= repository;
    }

    public string Name 
    { 
         get {return name;} 
         set 
         {
             if(String.IsNullOrWhiteSpace(value))
                 throw new ArgumentException();

             name = value;
        } 
    }
}

• I'm using ninject IoC.
• I abstract ninject container in an IFactory interface that has Get<>() method, so i want use only constructor injection. I do that because i don't want use [Inject] attributes.
• I want follow the always valid entity principle.

In this scenario i can't do that because i have a parameter on constructor. There is an another approach to do that?

Edit:

• I abstract ninject container in an IFactory interface that has Get<>() method, so i want use only constructor injection. I do that because i don't want use [Inject] attributes.

Abstraction of my the container:

interface IFactory
{
    T Get<T>();
    IEnumerable<T> GetAll<T>();
}

Implementation:

class ApplicationFactory : IFactory
{
    private readonly IKernel ninjectKernel = ApplicationNinjectKernel.BuildNew();

    public T Get<T>()
    {
        return ninjectKernel.Get<T>();
    }

    public IEnumerable<T> GetAll<T>()
    {
        return ninjectKernel.GetAll<T>();
    }
}

ApplicationNinjectKernel.BuildNew() creates and return a new StandarKernel() with the binds..

ConstructorArgument sounds bad to me. With this approach i will put some ugly thing on my code and also will miss type checking at project time. :/

Answer 1

If you are trying to use Ninject to resolve using a given customer name, you can do it like this:

var customer = kernel.Get<Customer>(new ConstructorArgument("name", "Bob"));

This also requires that you followed the convention of binding your ICustomerRepository in the Ninject Module and loaded it into the Ninject Kernel. Example:

public override void Load()
{
    Bind<ICustomerRepository>().To<CustomerRepository>();
}