I have a question regarding the MVC 3 and more exaclty about the views and models. I want to mention that I'm new to MVC so I'm oly learning it.
Basically for example lets take te registration form:
I have a controller, view and model, to register a new user.
AccountController
Register.chtml
AccountModel => RegisterationModel
Now, in registration model i have all the datamembers with data annotations, for example:
[Required]
[Display(Name = "User name")]
public string UserName { get; set; }
[Required]
[DataType(DataType.Password)]
[Display(Name = "Password")]
public string Password { get; set; }
This are then rendered in view.
What bothers me, or I don't really understand how to do it properly:
Ok I have RegistrationModel ... but later on, for example if i want to render the profile of the user, should i call registrationmodel again or then it will be profilemodel? So basically I will have a lot of the same models just to render the same thing ... no?
Can't I have then one general Model, something like user, and then User i can pass with RegistrationModel/ProfileModel to view.
Maybe it is a bit difficult to understand what I mean exactly, but how I imagine it: for example a user submits a form, everything is parsed and a User object is created with all the data members, then this User object is pased to DAL, where it is submitted to DB. Later on someone visits the profile of this user and the DAL, will return User object back which is then displyed.
The answer to your question is no you should generally separate your domain models from your view models. Consider a following scenario. Let's say you have a User model and your business logic allows you to both add a new user and edit an existing user. Let's say your user model looks like this:
public class User
{
[Required]
public int? UserId {get; set;}
[Required]
public string LastName {get; set;}
[Required]
public string FirstName {get; set;}
[Required]
public string Password {get; set;}
public bool IsAdmin {get; set;}
}
Now in order for your user model to be valid you have to have User ID to make the user identifiable. When you're inserting a new user you don't need the ID because that is something database will automatically take care of on insertion. However when you're doing an update of the user then you need the user ID to be populated. So now you have a model that in one case requires a field (UserId) but in another it doesn't. How are you going to handle that?
The answer is view models and this is the reason why they exist and why it's advised to create one for each entry form you have in your project. In this case you would end up with a different insert and update user view models. I know it's tedious to convert these view models into the underlying domain models but there are libraries to help you do that automatically like AutoMapper (https://github.com/AutoMapper/AutoMapper/wiki/Getting-started).
2nd and probably more serious problem is over posting. Suppose you are using the above User model to edit the user in your database. Now the model has an IsAdmin field which specifies whether user is an admin or not. Now your edit user view will omit this field since you don't want the general user to be able to make themselves an admin. But let's say you're dealing with a really smart user and he make a hidden field with id of IsAdmin and makes it value to be true:
<input type="hidden" id="IsAdmin" value="true" />
and then he/she posts the form to your save user url. Because you are using the domain logic user model which has IsAdmin property this hidden field will map to your model and this user just managed to make himself/herself and admin in your site. This is precisely why you need view models so this scenario can never happen.
Related
I originally asked this question when Identity was in beta. The classes and interfaces have changed considerably since then and it appears the RTW version has some modifications again over the RC version. In principle I need to achieve the following.
authenticate the local login against my usertable tblMembers which contains the userid field and password which are the two items I need to authenticate.
have access to my tblMember record/class via the Controller.User property (Prior to MVC5 identity I had achieved this using the membership provider methods.) regardless of if the user logged in via the localuser method or via one of the other OAuth providers (Twitter, Google etc).
Ability to display my own custom username despite the login method. Local users login with a userid 1234567 and a password, ideally I would like to display "John Smith (1234567)" regardless of the authentication method (local/Twitter etc)
Initially I'm unsure as to what my memberclass should be inheriting from It appears from the
aspIdentitySample project that I should be using IdentityUser?
public partial class tblMember
{
public int id { get; set; }
public string membership_id { get; set; }
public string password { get; set; }
....other fields
}
Are there any new or updated examples of integrating your existing database/user tables with the ASP.NET Identity system?
I am also adding the identity tables to my database. If you create a new web project in visual studio 2013 you will see that now in RTM everything works better than RC plus you will see the
following table
public class ApplicationUser : IdentityUser
{
}
So Instead of ApplicationUser you can call your table tblMembers
public class tblMembers : IdentityUser
{
}
your table tblMembers will inherit Id Username Password security stamp and a discriminator column saying this is a tblMemeber
without making custom classes for authentication the easiest thing to do would be just to make the username the combination of your old usernames and userids. Then store the users real name or old username without the user id in a separate column.
have the users register with the built in user login and they can go to manage account and click use another service to log in. This will link the Google account to their regular account, so no matter which one they use it will log them in to the same account. If you have users with connected table information, I suggest you seed your table with all the users with something similar to the register method found in the template.Then just match the new combined username and Id to the old ones and populate data where needed in sql management studio.
Again a lot of issues in RC with extending IdentityUsers have been fixed. Microsoft is already adding more features to the identity user store and this tutorial http://www.windowsazure.com/en-us/develop/net/tutorials/web-site-with-sql-database/ is supposed to be updated soon. I plan on making my own walk through when i'm done changing my database but for now I hope my suggestions even though they are a simpler solution than you might want to implement.
You can do this easily by modifying the IdentityModel.cs as per the below:
Override OnModelCreating in your DbContext then add the following, this will change AspNetUser table to "Users" you can also change the field names the default Id column will become User_Id.
modelBuilder.Entity<IdentityUser>()
.ToTable("Users", "dbo").Property(p => p.Id).HasColumnName("User_Id");
or simply the below if you want to keep all the standard column names:
modelBuilder.Entity<IdentityUser>()
.ToTable("Users", "dbo")
Full example below (this should be in your IdentityModel.cs file) i changed my ApplicationUser class to be called User.
public class User : IdentityUser
{
public string PasswordOld { get; set; }
public DateTime DateCreated { get; set; }
public bool Activated { get; set; }
public bool UserRole { get; set; }
}
public class ApplicationDbContext : IdentityDbContext<User>
{
public ApplicationDbContext()
: base("DefaultConnection")
{
}
protected override void OnModelCreating(System.Data.Entity.DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<IdentityUser>()
.ToTable("Users", "dbo").Property(p => p.Id).HasColumnName("User_Id");
modelBuilder.Entity<User>()
.ToTable("Users", "dbo").Property(p => p.Id).HasColumnName("User_Id");
}
}
Please note i have not managed to get this working if the current table exists.
Also note whatever columns you do not map the default ones will be created.
Hope that helps.
I'm starting to think (partially due to the lack of information in this area), that it may be easier to user the default identity classes, but to provide referential integrity to my own user table from the AspNetUsers table.
If i add a custom linking field into the AspNetUsers table is it possible to access my tables from the Controllers.User property? i.e. Controller.User.tblMember.Orders?
I have a model that looks kinda like this:
public class Notes
{
public int NoteID {get; set;}
public string Note {get; set;}
public int CustomerID {get; set;}
{
On the Notes Details view, I would like to be able to show Customer Name instead of CustomerID. Obviously if this were a Create or Edit view I use a dropdown list.
However I am not sure how to show the value and not the ID in a read only Details view.
Thanks!
Code First is mainly... code, not Database logic.
So, instead of having the Foreign Keys (like CustomerID) in your models (it's also possible, and sometimes needed, but not always), you'll be more confortable having a reference property
public virtual Customer Customer {get;set;}
So in your view having Notes as Model, you could simply use
#Html.DisplayFor(m => m.Customer.Name);
When you retrieve your Notes entity, don't forget to include the related entities / properties needed for your View / ViewModel (I let you read about lazy loading)
You can try this:
var applicationDbContext = _context.Notes.Include(n => n.Custumer);
return View(await applicationDbContext.ToListAsync());
This code must be in your controller, in the Index method or whatever you named it.
And this is in view.
#Html.DisplayFor(modelItem => item.Customer.Name)
I have an mvc3 create page using a View Model with 2 entities
like
class ViewModel1{
public User user{get;set;}
public Company company{get;set;}
}
where User and Company are EF4 entities(tables). I need to use a single page to create both(related) tables. Now the Company entity is optional under some conditions and I use jQuery to hide the corresponding section in the view.
However since company has required fields , the post back create function has ModelState.Valid as false.
What I want to do is if the Company section is hidden, I would like to skip validating the Company entity in ViewModel in Server( I avoid validation of hidden elements in Client).
Maybe there is a better and more proper approach to this?
What you have shown is not a view model. You call it a view model but it isn't because it is referencing your EF domain entities.
A more realistic view model would look like this:
class ViewModel1
{
public UserViewModel User { get;set; }
public CompanyViewModel Company { get; set; }
}
or even flattened out and containing only the properties that your view needs:
class ViewModel1
{
public int UserId { get;set; }
[Required]
public string FullUserName { get;set; }
[Required]
public string CompanyName { get; set; }
}
Now depending on your specific requirements about view model validation your UserViewModel and CompanyViewModel classes will be specifically designed for them.
Instead of putting the entities directly in the view model, put the properties for the entities in the view model and map between the view model and the actual entity objects on the server. That way you can control what properties are required for your view. Create some custom validation rules to validate that the required company properties are there when some company information is required. To do this on the server, you can have your view model implement IValidatableObject and implement the logic in the Validate method. On the client you can add rules to the jQuery validate plugin for the "required if" properties.
public class UserCreationViewModel : IValidatableObject
{
[Required]
public string Username { get; set; }
[Required]
public string FirstName { get; set; }
...
public string CompanyName { get; set; }
public string CompanyEmail { get; set; }
public IEnumerable<ValidationResult> Validate( ValidationContext context )
{
if (!string.IsNullOrEmpty(CompanyName) && string.IsNullOrEmpty(CompanyEmail))
{
return yield new ValidationResult("Company Email is required if you specify a company", new [] { "CompanyEmail" });
}
}
}
I'm not sure what I would do on the client-side. You have a choice of either adding specific rules to the validate plugin directly, but it might be hard to make it look exactly the same as using the unobtrusive validation that MVC adds. Alternatively, you could look at adding/removing the unobtrusive attributes from the "required if" elements using jQuery depending on the state of the elements that trigger their requirement. I suggest trying both ways -- look at the docs for the validate plugin to see how to add custom rules and examine the code emitted by the MVC framework for the unobtrusive validate to see what you would need to add to make that work.
Another possibility would be including/removing a partial view with the company properties in the from based on whether the company information is required or not. That is, type in a company name and use AJAX to grab the inputs required for the company and add them to the form. If the company name is deleted, delete the elements. Leave the server-side validation the way it is, but in the partial view mimic the HTML that the framework would add in for unobtrusive validation. This is sort of the best of both worlds as the jQuery code is much simpler and you get consistent validation, too.
There are many ways you can achieve,
1) more commonly donot use [Required] attribute on Company object, but have proper validation for parameters inside Company object.
In this case if Company object is null still validation will pass, but if Company object isnot null it will validate each properties.
2) If validation involves some complex business logic, then go for Self Validating Model. (inherit from IValiddatableObject, and override Validate(...).
3) By code, in the controller.
if(model.company == null)
this.ModelState.Keys.Where(k => k.Contains("company")).ToList().ForEach(k => this.ModelState.Remove(k));
first two are best approved approaches, third is just another way to achieve your functionalities
I am working on an ASP.Net MVC3 application and I'm having trouble understanding the "right way" to do the validation I'm looking for.
For example, consider a model that looks like this:
[Required]
[StringLength(10, MinimumLength = 10)]
[RegularExpression("[0-9]{10}")]
public string Id { get; set; }
[Required]
public string Value { get; set; }
If I have an Id of "2342" and try to POST back, the model mapping kicks in and registers an error because of the length validation. However, if perform a GET against /controller/2342, then MVC seems to happily create a model with this invalid state (ModelState.Valid will be true). I could create some validations in the controller to catch this, but it seems redundant.
What is the best way to do this?
Thanks!
Jacob
When you perform a GET, you are simply retrieving a model with a given ID. So there is no validation performed. If you really want to make sure that requested model IDs should be 10 numbers in length, you should define constraint in Global.asax:
routes.MapRoute(
"Product",
"Product/{productId}",
new {controller="Product", action="Details"},
new {productId = #"[0-9]{10}" }
);
There is nothing in the framework that by default validates a model on a GET request as validation isn't generally required at that time. If you do want to force a validation here, this was answered in this prior question
See:
Validate model on initial request
I have a Razor MVC3 project which has two user records in a form, one for the key contact and one for a backup contact. For example;
public class User
{
[Required(ErrorMessage = "First name is required")]
public string FirstName { get; set; }
}
Validation all works well except for the small issue where the user fails to fill out a field, it says 'First name is required' but I'd like to point the user to which one of the first name fields is missing. Such as 'Backup contact first name is required' or 'Key contact first name is required'.
Ideally I'd like to leave the [Required] annotation on the class as it is used elsewhere.
This seems like one of those small cases that might have been missed and is not easily achieved, but please prove me wrong.
Ryan
One way you can accomplish this is with a separate view model for this screen, instead of a single User model with all the error messages. In the new view model, you could have a BackupContactFirstName property, KeyContactFirstName property, etc each with its separate error message. (Alternatively this view model could contain separate User models as properties, but I've found that Microsoft's client validation doesn't play well with complex models and prefers flat properties).
Your view model would look like this:
public class MySpecialScreenViewModel
{
[Required(ErrorMessage = "Backup contact first name is required")]
public string BackupContactFirstName { get; set; }
[Required(ErrorMessage = "Key contact first name is required")]
public string KeyContactFirstName { get; set; }
}
Then pass your view model to the view like this:
#model MySpecialScreenViewModel
...
Your post controller action would collect the properties from the view model (or map them to separate User models) and pass them to the appropriate data processing methods.
An alternative I have stumbled across, just modify the ModelState collection. It will have the elements in a collection named by index, like 'User_0__EmailAddress' and you can adjust / amend / replace the Errors collection associated with that key.
[Required(ErrorMessage = "{0} is required")]
{0}=The DisplayName is automatically placed on it
sample
[DisplayName("Amount per square meter")]
[Required(ErrorMessage = "{0} is required")]
public int PriceMeter { get; set; }
output
Amount per square meter is required