MVC Entity Framework Mapper to View Model to Update table - asp.net-mvc

Question

Again...
I am doing a MVC with EF5 App. I have a Users Entity, that EF bind with Users table in Database... Looks like this.
public partial class Users
{
public long User_id { get; set; }
[Required]
[StringLength(30, ErrorMessage = "LastName cannot be longer than 30 characters.")]
public string LastName { get; set; }
[Required]
[StringLength(30, ErrorMessage = "Name cannot be longer than 30 characters.")]
public string Name { get; set; }
public int ProcessState_id { get; set; }
public string Sex { get; set; }
[Required,Range(1, int.MaxValue, ErrorMessage = "El País es Obligatorio")]
public int Country_id { get; set; }
[Required]
[EmailAddress(ErrorMessage = "Invalid Email Address")]
public string Email { get; set; }
public System.DateTime CreationDate { get; set; }
public Nullable<System.DateTime> UpDateTime { get; set; }
[RegularExpression(#"^.{5,}$", ErrorMessage = "Minimum 3 characters required")]
[Required]
[StringLength(9, MinimumLength = 3, ErrorMessage = "Password cannot be longer than 9 characters.")]
public string Password { get; set; }
public string Url { get; set; }
public byte[] Picture { get; set; }
public string CodArea { get; set; }
public string PhoneNumber { get; set; }
public virtual Countries Countries { get; set; }
public virtual ProcessStates ProcessStates { get; set; }
public virtual States States { get; set; }
[NotMapped] // Does not effect with your database
[RegularExpression(#"^.{5,}$", ErrorMessage = "Minimum 3 characters required")]
[StringLength(9, MinimumLength = 3, ErrorMessage = "Confirm Password cannot be longer than 9 characters.")]
[Compare("Password")]
public virtual string ConfirmPassword { get; set; }
}
I have a Model Class that i use it in my Create View....
public class UserViewModel
{
public Users user { get; set; }
public IList<SelectListItem> AvailableCountries { get; set; }
}
My Create Method in the Controller gets a UserViewModel instance...
My Create Method looks like this.
public async Task<ActionResult> Create(UserViewModel model, System.Web.HttpPostedFileBase image = null)
{
try
{
if (ModelState.IsValid)
{
model.user.ProcessState_id = Security.WAITING;
model.user.Rol_id = Security.ROL_PUBLIC;
model.user.CreationDate = DateTime.Now;
model.user.IP = Request.UserHostAddress;
model.user.Url = UserValidation.EncriptacionURL(model.user.Email);
if (image != null)
{
// product.ImageMimeType = image.ContentType;
model.user.Picture= new byte[image.ContentLength];
image.InputStream.Read(model.user.Picture, 0, image.ContentLength);
}
_db.Users.Add(model.user);
_db.SaveChanges();
return RedirectToAction("Create");
}
model.AvailableCountries = GetCountries();
return View(model);
}
catch (RetryLimitExceededException /* dex */)
{
}
return View(model);
}
So far so good.
For my Edit View, i need less properties from User class, so I have a new class with the properties I need. This class is called UserEditView.
public class UserEditView
{
public long User_id { get; set; }
[Required]
[StringLength(30, ErrorMessage = "LastName cannot be longer than 30 characters.")]
public string LastName { get; set; }
[Required]
[StringLength(30, ErrorMessage = "Name cannot be longer than 30 characters.")]
public string Name { get; set; }
[Required, Range(1, int.MaxValue, ErrorMessage = "El País es Obligatorio")]
public int Country_id { get; set; }
[Required]
[EmailAddress(ErrorMessage = "Invalid Email Address")]
public string Email { get; set; }
public Nullable<System.DateTime> UpDateTime { get; set; }
public byte[] Picture { get; set; }
public string CodArea { get; set; }
public string PhoneNumber { get; set; }
public virtual Countries Countries { get; set; }
}
I also create a new Model for Edit View, called UserEditViewModel and looks like this.
public class UserEditViewModel
{
public UserEditView user { get; set; }
public IList<SelectListItem> AvailableCountries { get; set; }
}
On my Edit method, I use Mapper to bind User entity with UserEditView
public ViewResult Edit(int User_id=3)
{
Users users = _db.Users
.FirstOrDefault(p => p.User_id == User_id);
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<Users, UserEditView>();
});
IMapper mapper = config.CreateMapper();
UserEditView userEditView = mapper.Map<Users, UserEditView>(users);
var model = new UserEditViewModel
{
user = userEditView,
AvailableCountries = GetCountries(),
};
return View(model);
}
My problem arise when I want to Update the User table.
The Edit method gets UserEditViewModel instance.
public async Task<ActionResult> Edit(UserEditViewModel model, System.Web.HttpPostedFileBase image = null)
{
try
{
if (ModelState.IsValid)
{}
}
}
UserEditViewModel has an instance of UserEditView but I need an instance of Users in order to EF updates Users Table.
I need to Map again?
How can I get a Users Instance?
I add the following Class
public static class AutoMapperBootStrapper
{
public static void BootStrap()
{
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<Users, UserEditView>();
cfg.CreateMap<UserEditView, Users>();
});
IMapper mapper = config.CreateMapper();
}
And I add in my Global.asax
public class MvcApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AutoMapperBootStrapper.BootStrap();
AreaRegistration.RegisterAllAreas();
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
}
}
then in the controller... i do
public ViewResult Edit(int User_id=3)
{
Users users = _db.Users.FirstOrDefault(p => p.User_id == User_id);
UserEditView userEditView = Mapper.Map<Users, UserEditView>(users);
}
But Mapper.Map have an error... it says Mapper is not instantiated.
the problem is because I defined more than one Mapper. If i define just one, it Works fine...

Answer 1

I need to Map again? How can I get a Users Instance?
You could get the User model from your database using the id and then map the properties that you need to be updated from the view model:
[HttpPost]
public ActionResult Edit(UserEditViewModel model, HttpPostedFileBase image = null)
{
if (!ModelState.IsValid)
{
// Validation failed => redisplay the Edit form so that the
// user can correct the errors
return View(model);
}
var user = _db.Users.FirstOrDefault(p => p.User_id == model.user.User_id);
if (user == null)
{
// no user with the specified id has been found in the database =>
// there's nothing to update
return NotFound();
}
// This will map only the properties of the user object that
// are part of the view model
Mapper.Map<Users, UserEditView>(model.user, user);
// at this stage you could manually update some properties that
// have not been mapped such as the uploaded image
// finally persist the changes to the database
_db.SaveChanges();
// redirect to some other action to show the updated users
return RedirectToAction("users");
}
Also the code you have shown in your question:
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<Users, UserEditView>();
});
IMapper mapper = config.CreateMapper();
This is absolutely NOT something that you should be doing inside a controller action. AutoMapper mappings should be configured only once per application lifetime, ideally when your application starts, i.e. for a web application that would be Application_Start in Global.asax. In a controller action you should only use the already configured mappings. I strongly recommend you going through the AutoMapper's documentation for getting better understanding of how to use this framework.
Quote from the documentation:
Where do I configure AutoMapper?
If you're using the static Mapper method, configuration should only
happen once per AppDomain. That means the best place to put the
configuration code is in application startup, such as the Global.asax
file for ASP.NET applications. Typically, the configuration
bootstrapper class is in its own class, and this bootstrapper class is
called from the startup method. The bootstrapper class should call
Mapper.Initialize to configure the type maps.