> For the complete documentation index, see [llms.txt](https://jen-hsuan-hsieh.gitbook.io/asp-net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jen-hsuan-hsieh.gitbook.io/asp-net/chapter1/1.1.the-complete-asp.net-mvc-5-course/16-building-restful-api/164-data-transfer-object.md).

# 1.6.4. Data Transfer Object

* To seperate domain models and conroller
* 1.Create a new folder whichh is called DTO
* 2.Create DTO object to DTO folder

  ```
    public class CustomerDto
    {
        public int Id { get; set; }

        [Required]
        [StringLength(255)]
        public string Name { get; set; }

        public bool IsSubscribeToNesletter { get; set; }

        public byte membershipTypeId { get; set; }

        [Min18YearsIfAMember]
        public string Birthday { get; set; }
    }
  ```
* 3.Install automapper:
  * nuget console:

    ```
      install-package automapper -version:4.1
    ```
* 4.Add a profile class (MappingProfile.cs) in App\_start folder:

  ```
  namespace Vidly2.App_Start
  {
    public class MappingProfile: Profile
    {
        public MappingProfile()
        {
            Mapper.CreateMap<Customer, CustomerDto>();
            Mapper.CreateMap<CustomerDto, Customer>();
        }
    }
  }
  ```
* 5.Edit Clobal.asax.cs:

  ```
    public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            Mapper.Initialize(c => c.AddProfile<MappingProfile>());
            GlobalConfiguration.Configure(WebApiConfig.Register);
            AreaRegistration.RegisterAllAreas();
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
        }
    }
  ```
* 6.Modify controller:

  ```
    public class CustomersController : ApiController
    {
        private ApplicationDbContext _context;

        public CustomersController()
        {
            _context = new ApplicationDbContext();
        }

        // GET /api/customers
        [HttpGet]
        public IEnumerable<CustomerDto> GetCustomers()
        {
            return _context.Customers.ToList().Select(Mapper.Map<Customer, CustomerDto>);
        }

        // GET /api/customers/1
        public CustomerDto GetCustomers(int id)
        {
            var customer = _context.Customers.SingleOrDefault(c => c.Id == id);

            if (customer == null)
            {
                throw new HttpResponseException(HttpStatusCode.NotFound);
            }

            return Mapper.Map<Customer, CustomerDto>(customer);
        }

        // POST /api/customers
        [HttpPost]
        public CustomerDto CreateCustomers(CustomerDto customerDto)
        {
            if (!ModelState.IsValid)
            {
                throw new HttpResponseException(HttpStatusCode.BadRequest);
            }
            var customer = Mapper.Map<CustomerDto, Customer>(customerDto);
            _context.Customers.Add(customer);
            _context.SaveChanges();
            customerDto.Id = customer.Id;
            return customerDto;
        }

        // PUT /api/customers/1
        [HttpPut]
        public void UpdateCustomers(int id, CustomerDto customerDto)
        {
            if (!ModelState.IsValid)
            {
                throw new HttpResponseException(HttpStatusCode.BadRequest);
            }

            var customerInDb = _context.Customers.SingleOrDefault(c => c.Id == id);

            if (customerInDb == null)
            {
                throw new HttpResponseException(HttpStatusCode.NotFound);
            }

            Mapper.Map(customerDto, customerInDb);

            _context.SaveChanges();
        }

        // PUT /api/customers/1
        [HttpDelete]
        public void DeleteCustomers(int id)
        {
            var customerInDb = _context.Customers.SingleOrDefault(c => c.Id == id);

            if (customerInDb == null)
            {
                throw new HttpResponseException(HttpStatusCode.NotFound);
            }

            _context.Customers.Remove(customerInDb);
            _context.SaveChanges();
        }
    }
  ```