これは、制御の反転の例ですか？

Question

James Kovacの Inversion on Control and Dependency Injectionの記事を終了しましたそして、私が学んだことを使用して、以下に示す独自のIoC / DIの例を作成しました。

この例は非常に満足しています。

• IoCのテスト容易性 アスペクトは、リポジトリとMockRepositoryの両方を渡すことで顧客をインスタンス化するという点で
• また、承認サービスは分離されています。異なるルールで別の認可サービスを作成すると、他の条件に基づいてそれらを簡単に交換できます

しかし、ここからの進歩に目を向けると、奇妙なことに思えます：

• 「コンテナ」がないようです。私の顧客クラスは「コンテナとして機能」していますか？この意味で？
• これをWPFに移植する場合、モジュール（Prismの観点から）がこの例に適合する場所（たとえば、AuthorizationServiceとRepositoryはモジュールになりますか？）
• これをWPFに移植する場合、 MVVMはどこに収まりますか？依存性注入を介してMVVMの一部を持っているか、MVVMがまったく別のものです。

ご意見をお寄せいただきありがとうございます。

コメントに基づく新しいコード：

using System;
using System.Linq;
using System.Collections.Generic;

namespace TestSimpleDependencyInjection1
{
    class Program
    {
        static void Main(string[] args)
        {
            AuthorizationService authorizationService = new AuthorizationService();

            //real example
            Repository repository = new Repository(authorizationService);
            for (int id = 1; id <= 3; id++)
            {
                Customer customer = repository.GetCustomer(id);
                customer.Display();
            }
            Console.WriteLine();

            //mock test example
            MockRepository mockRepository = new MockRepository(authorizationService);
            Customer mockCustomerAdministrator = repository.GetCustomer(1);
            Customer mockCustomerSalesperson = repository.GetCustomer(2);
            UnitTester.Assert("Administrators have access", mockCustomerAdministrator.GetAuthorizationMessage(), "Access Granted");
            UnitTester.Assert("Salespeople do not have access", mockCustomerAdministrator.GetAuthorizationMessage(), "Access Granted");

            Console.ReadLine();
        }
    }

    public static class UnitTester
    {
        public static void Assert(string title, string value, string expectedResult)
        {
            Console.WriteLine(value == expectedResult ? String.Format("{0}: test succeeded", title) : String.Format("{0}: TEST FAILED!", title));
        }
    }

    public class Customer
    {

        public int ID { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public AccessGroup AccessGroup { get; set; }
        public AuthorizationService AuthorizationService { get; set; }

        public string GetAuthorizationMessage()
        {
            return this.AuthorizationService.GetAccessMessage(this);
        }

        public Customer()
        {

        }

        public void Display()
        {
            Console.WriteLine("Customer: {1}, {0} ({2}): {3}", this.FirstName, this.LastName, this.AccessGroup, this.GetAuthorizationMessage());
        }
    }

    public class AuthorizationService
    {
        public string GetAccessMessage(Customer customer)
        {
            return customer.AccessGroup == AccessGroup.Administrator ? "Access Granted" : "Access Denied";
        }
    }


    public class Repository : IRepository
    {
        private List<Customer> _customerSet = new List<Customer>();
        private AuthorizationService _authorizationService;

        public Repository(AuthorizationService authorizationService)
        {
            _authorizationService = authorizationService;
            _customerSet.Add(new Customer {AuthorizationService = _authorizationService, ID = 1, FirstName = "Jim", LastName = "Smith", AccessGroup = AccessGroup.Administrator });
            _customerSet.Add(new Customer {AuthorizationService = _authorizationService, ID = 2, FirstName = "John", LastName = "Johnson", AccessGroup = AccessGroup.Administrator });
            _customerSet.Add(new Customer {AuthorizationService = _authorizationService, ID = 3, FirstName = "Hank", LastName = "Rivers", AccessGroup = AccessGroup.Salesperson });
        }

        public Customer GetCustomer(int id)
        {
            return (from c in _customerSet
                    where c.ID == id
                    select c).SingleOrDefault();
        }
    }

    public class MockRepository : IRepository
    {
        private List<Customer> _customerSet = new List<Customer>();
        private AuthorizationService _authorizationService;

        public MockRepository(AuthorizationService authorizationService)
        {
            _authorizationService = authorizationService;
            _customerSet.Add(new Customer { AuthorizationService = _authorizationService, ID = 1, FirstName = "Test1AdministratorFirstName", LastName = "Test1AdministratorLastName", AccessGroup = AccessGroup.Administrator });
            _customerSet.Add(new Customer { AuthorizationService = _authorizationService, ID = 2, FirstName = "Test2SalespersonFirstName", LastName = "Test2SalesPersonLastName", AccessGroup = AccessGroup.Salesperson });
        }

        public Customer GetCustomer(int id)
        {
            return (from c in _customerSet
                            where c.ID == id
                            select c).SingleOrDefault();
        }

    }

    public interface IRepository
    {
        Customer GetCustomer(int id);
    }

    public enum AccessGroup
    {
        Administrator,
        Salesperson
    }
}

リクエストごと、ここに元のコードがあります：

using System;
using System.Collections.Generic;

namespace TestSimpleDependencyInjection1
{
    class Program
    {
        static void Main(string[] args)
        {
            AuthorizationService authorizationService = new AuthorizationService();

            //real example
            Repository repository = new Repository();
            for (int id = 1; id <= 3; id++)
            {
                Customer customer = new Customer(id, authorizationService, repository);
                customer.Display();
            }
            Console.WriteLine();

            //mock test example
            MockRepository mockRepository = new MockRepository();
            Customer mockCustomerAdministrator = new Customer(1, authorizationService, mockRepository);
            Customer mockCustomerSalesperson = new Customer(2, authorizationService, mockRepository);
            UnitTester.Assert("Administrators have access", mockCustomerAdministrator.GetAuthorizationMessage(), "Access Granted");
            UnitTester.Assert("Salespeople do not have access", mockCustomerAdministrator.GetAuthorizationMessage(), "Access Granted");

            Console.ReadLine();
        }
    }

    public static class UnitTester
    {
        public static void Assert(string title, string value, string expectedResult)
        {
            Console.WriteLine(value == expectedResult ? String.Format("{0}: test succeeded", title) : String.Format("{0}: TEST FAILED!", title));
        }
    }

    public class Customer
    {
        private AuthorizationService authorizationService;
        private IRepository repository;

        public int ID { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public AccessGroup AccessGroup { get; set; }

        public string GetAuthorizationMessage()
        {
            return authorizationService.GetAccessMessage(this);
        }

        public Customer(int id, AuthorizationService authorizationService, IRepository repository)
        {
            this.authorizationService = authorizationService;
            this.repository = repository;

            CustomerDB customerDB = repository.GetCustomerDB(id);
            this.ID = customerDB.ID;
            this.FirstName = customerDB.FirstName;
            this.LastName = customerDB.LastName;
            this.AccessGroup = customerDB.AccessGroup;
        }

        public void Display()
        {
            Console.WriteLine("Customer: {1}, {0} ({2}): {3}", this.FirstName, this.LastName, this.AccessGroup, this.GetAuthorizationMessage());
        }
    }

    public class AuthorizationService
    {
        public string GetAccessMessage(Customer customer)
        {
            return customer.AccessGroup == AccessGroup.Administrator ? "Access Granted" : "Access Denied";
        }
    }


    public class Repository : IRepository
    {
        private List<CustomerDB> _customerDBSet = new List<CustomerDB>();

        public Repository()
        {
            _customerDBSet.Add(new CustomerDB { ID = 1, FirstName = "Jim", LastName = "Smith", AccessGroup = AccessGroup.Administrator });
            _customerDBSet.Add(new CustomerDB { ID = 2, FirstName = "John", LastName = "Johnson", AccessGroup = AccessGroup.Administrator });
            _customerDBSet.Add(new CustomerDB { ID = 3, FirstName = "Hank", LastName = "Rivers", AccessGroup = AccessGroup.Salesperson });
        }

        public CustomerDB GetCustomerDB(int id)
        {
            CustomerDB customerDBchosen = null;
            //this should be done with LINQ (couldn't get it CustomerDB to implement IEnumerable correctly)
            foreach (CustomerDB customerDB in _customerDBSet)
            {
                if (customerDB.ID == id)
                {
                    customerDBchosen = customerDB;
                    break;
                }
            }
            return customerDBchosen;
        }
    }

    public class MockRepository : IRepository
    {
        public CustomerDB GetCustomerDB(int id)
        {
            switch (id)
            {
                case 1:
                    return new CustomerDB { ID = 1, FirstName = "Test1AdministratorFirstName", LastName = "Test1AdministratorLastName", AccessGroup = AccessGroup.Administrator };
                case 2:
                    return new CustomerDB { ID = 2, FirstName = "Test2SalespersonFirstName", LastName = "Test2SalesPersonLastName", AccessGroup = AccessGroup.Salesperson };
                default:
                    return null;
            }
        }
    }

    public interface IRepository
    {
        CustomerDB GetCustomerDB(int id);
    }

    public class CustomerDB
    {
        public int ID { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public AccessGroup AccessGroup { get; set; }
    }

    public enum AccessGroup
    {
        Administrator,
        Salesperson
    }
}

Answer 1

あなたのコードは非常に深刻な方法で単一の責任プリンシパルに違反しています。

http://en.wikipedia.org/wiki/Single_responsibility_principle

Customerオブジェクトがリポジトリから自身をロードするのではなく、リポジトリがCustomerオブジェクトをロードして呼び出し元に返す必要があります。

次のようなものが期待されます：

Customer customer = repository.GetCustomer(3);

Answer 2

ほとんどの場合、Switchステートメントの使用はSRPに違反します。コード内のswitchステートメントを削除する方法については、これを確認してください。挑戦と疎結合コードを書くことの美しさは、もしそうでなければ＆amp; switchステートメント。