src/CleanArchitecture.Web/Api/ToDoItems2Controller.cs

+using CleanArchitecture.Web.ApiModels;
+using CleanArchitecture.Web.Filters;
+using CleanArchitecture.Web.Services;
+using Microsoft.AspNetCore.Mvc;
+using System.Threading.Tasks;
+
+namespace CleanArchitecture.Web.Api
+{
+    [Route("api/[controller]")]
+    [ValidateModel]
+    public class ToDoItems2Controller : Controller
+    {
+        private readonly IToDoAppService _appService;
+
+        public ToDoItems2Controller(IToDoAppService appService)
+        {
+            _appService = appService;
+        }
+
+        [HttpGet]
+        public IActionResult List()
+        {
+            var items = _appService.List();
+            return Ok(items);
+        }
+
+        [HttpGet("{id:int}")]
+        public IActionResult GetById(int id)
+        {
+            var item = _appService.GetById(id);
+            return Ok(item);
+        }
+
+        [HttpPost]
+        public async Task<IActionResult> Post([FromBody] ToDoItemDTO item)
+        {
+            var createdItem = _appService.CreateItem(item);
+            return Ok(createdItem);
+        }
+
+        [HttpPost("{itemId}")]
+        public async Task<IActionResult> MarkComplete(int itemId)
+        {
+            _appService.MarkComplete(itemId);
+
+            return Ok();
+        }
+    }
+}

src/CleanArchitecture.Web/Api/ToDoItems3Controller.cs

+using CleanArchitecture.Web.ApiModels;
+using CleanArchitecture.Web.Commands;
+using CleanArchitecture.Web.Filters;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+using System.Threading.Tasks;
+
+namespace CleanArchitecture.Web.Api
+{
+
+
+    [Route("api/[controller]")]
+    [ValidateModel]
+    public class ToDoItems3Controller : Controller
+    {
+        private readonly IMediator _mediator;
+
+        public ToDoItems3Controller(IMediator mediator)
+        {
+            _mediator = mediator;
+        }
+
+        [HttpGet]
+        public async Task<IActionResult> List()
+        {
+            var items = await _mediator.Send(new ListItemsCommand());
+            return Ok(items);
+        }
+
+        [HttpGet("{id:int}")]
+        public async Task<IActionResult> GetById(int id)
+        {
+            var command = new GetItemCommand { Id = id };
+            var item = await _mediator.Send(command);
+            return Ok(item);
+        }
+
+        [HttpPost]
+        public async Task<IActionResult> Post([FromBody] ToDoItemDTO item)
+        {
+            var command = new CreateItemCommand { ItemToCreate = item };
+            var createdItem = await _mediator.Send(command);
+            return Ok(createdItem);
+        }
+
+        [HttpPost("{itemId}")]
+        public async Task<IActionResult> MarkComplete(int itemId)
+        {
+            var command = new MarkItemCompleteCommand { Id = itemId };
+
+            await _mediator.Send(command);
+
+            return Ok();
+        }
+    }
+}

src/CleanArchitecture.Web/Api/ToDoItemsController.cs

-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-using CleanArchitecture.Core.Entities;
+using CleanArchitecture.Core.Entities;
 using CleanArchitecture.Core.Interfaces;
 using CleanArchitecture.Web.ApiModels;
 using CleanArchitecture.Web.Filters;
 using Microsoft.AspNetCore.Mvc;
+using System.Linq;
+using System.Threading.Tasks;
 
 namespace CleanArchitecture.Web.Api
 {
@@ -21,7 +19,6 @@ namespace CleanArchitecture.Web.Api
             _todoRepository = todoRepository;
         }
 
-        // GET: api/ToDoItems
         [HttpGet]
         public IActionResult List()
         {
@@ -30,7 +27,6 @@ namespace CleanArchitecture.Web.Api
             return Ok(items);
         }
 
-        // GET: api/ToDoItems
         [HttpGet("{id:int}")]
         public IActionResult GetById(int id)
         {
@@ -38,7 +34,7 @@ namespace CleanArchitecture.Web.Api
             return Ok(item);
         }
 
-        // POST: api/ToDoItems
+        [HttpPost]
         public async Task<IActionResult> Post([FromBody] ToDoItemDTO item)
         {
             var todoItem = new ToDoItem()
@@ -49,5 +45,15 @@ namespace CleanArchitecture.Web.Api
             _todoRepository.Add(todoItem);
             return Ok(ToDoItemDTO.FromToDoItem(todoItem));
         }
+
+        [HttpPost("{itemId}")]
+        public async Task<IActionResult> MarkComplete(int itemId)
+        {
+            var item = _todoRepository.GetById(itemId);
+            item.MarkComplete();
+            _todoRepository.Update(item);
+
+            return Ok();
+        }
     }
 }

src/CleanArchitecture.Web/ApiModels/ToDoItemDTO.cs

-using System;
-using System.Collections.Generic;
+using CleanArchitecture.Core.Entities;
 using System.ComponentModel.DataAnnotations;
-using System.Linq;
-using System.Threading.Tasks;
-using CleanArchitecture.Core.Entities;
 
 namespace CleanArchitecture.Web.ApiModels
 {

src/CleanArchitecture.Web/CleanArchitecture.Web.csproj

@@ -24,6 +24,7 @@
 
   <ItemGroup>
     <PackageReference Include="Dapper" Version="1.50.2" />
+    <PackageReference Include="MediatR.Extensions.Microsoft.DependencyInjection" Version="3.0.0" />
     <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.0" PrivateAssets="All" />
     <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.0.0" PrivateAssets="All" />

src/CleanArchitecture.Web/Commands/CreateItemCommand.cs

+using CleanArchitecture.Web.ApiModels;
+using MediatR;
+
+namespace CleanArchitecture.Web.Commands
+{
+    public class CreateItemCommand : IRequest<ToDoItemDTO>
+    {
+        public ToDoItemDTO ItemToCreate { get; set; }
+    }
+}

src/CleanArchitecture.Web/Commands/GetItemCommand.cs

+using CleanArchitecture.Web.ApiModels;
+using MediatR;
+
+namespace CleanArchitecture.Web.Commands
+{
+    public class GetItemCommand : IRequest<ToDoItemDTO>
+    {
+        public int Id { get; set; }
+    }
+}

src/CleanArchitecture.Web/Commands/ListItemsCommand.cs

+using CleanArchitecture.Web.ApiModels;
+using MediatR;
+using System.Collections.Generic;
+
+namespace CleanArchitecture.Web.Commands
+{
+    public class ListItemsCommand : IRequest<List<ToDoItemDTO>>
+    {
+    }
+}

src/CleanArchitecture.Web/Commands/MarkItemCompleteCommand.cs

+using MediatR;
+
+namespace CleanArchitecture.Web.Commands
+{
+    public class MarkItemCompleteCommand : IRequest
+    {
+        public int Id { get; set; }
+    }
+}

src/CleanArchitecture.Web/Handlers/ListItemsHandler.cs

+using CleanArchitecture.Core.Entities;
+using CleanArchitecture.Core.Interfaces;
+using CleanArchitecture.Web.ApiModels;
+using CleanArchitecture.Web.Commands;
+using MediatR;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace CleanArchitecture.Web.Handlers
+{
+    public class ListItemsHandler : IRequestHandler<ListItemsCommand, List<ToDoItemDTO>>
+    {
+        private readonly IRepository<ToDoItem> _todoRepository;
+
+        public ListItemsHandler(IRepository<ToDoItem> todoRepository)
+        {
+            _todoRepository = todoRepository;
+        }
+        public List<ToDoItemDTO> Handle(ListItemsCommand message)
+        {
+            return _todoRepository.List()
+                .Select(ToDoItemDTO.FromToDoItem)
+                .ToList();
+        }
+    }
+}

src/CleanArchitecture.Web/Services/IToDoAppService.cs

+using CleanArchitecture.Web.ApiModels;
+using System.Collections.Generic;
+
+namespace CleanArchitecture.Web.Services
+{
+    public interface IToDoAppService
+    {
+        ToDoItemDTO GetById(int id);
+        ToDoItemDTO CreateItem(ToDoItemDTO itemToCreate);
+        IEnumerable<ToDoItemDTO> List();
+        void MarkComplete(int itemId);
+    }
+}

src/CleanArchitecture.Web/Services/ToDoAppService.cs

+using CleanArchitecture.Core.Entities;
+using CleanArchitecture.Core.Interfaces;
+using CleanArchitecture.Web.ApiModels;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace CleanArchitecture.Web.Services
+{
+    public class ToDoAppService : IToDoAppService
+    {
+        private readonly IRepository<ToDoItem> _todoRepository;
+
+        public ToDoAppService(IRepository<ToDoItem> todoRepository)
+        {
+            _todoRepository = todoRepository;
+        }
+
+        public ToDoItemDTO CreateItem(ToDoItemDTO itemToCreate)
+        {
+            var todoItem = new ToDoItem()
+            {
+                Title = itemToCreate.Title,
+                Description = itemToCreate.Description
+            };
+            _todoRepository.Add(todoItem);
+            return ToDoItemDTO.FromToDoItem(todoItem);
+        }
+
+        public ToDoItemDTO GetById(int id)
+        {
+            return ToDoItemDTO.FromToDoItem(_todoRepository.GetById(id));
+        }
+
+        public IEnumerable<ToDoItemDTO> List()
+        {
+            return _todoRepository.List()
+                            .Select(item => ToDoItemDTO.FromToDoItem(item));
+        }
+
+        public void MarkComplete(int itemId)
+        {
+            var item = _todoRepository.GetById(itemId);
+            item.MarkComplete();
+            _todoRepository.Update(item);
+        }
+    }
+}

src/CleanArchitecture.Web/Startup.cs

@@ -9,6 +9,7 @@ using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using StructureMap;
+using MediatR;
 
 namespace CleanArchitecture.Web
 {
@@ -32,6 +33,8 @@ namespace CleanArchitecture.Web
             services.AddMvc()
                 .AddControllersAsServices();
 
+            services.AddMediatR();
+
             var container = new Container();
 
             container.Configure(config =>