Sunday, October 1, 2023

Seed Users and Roles using EF Code First approach in ASP.NET Razor Pages

In this tutorial, I shall describe the steps you need to follow if you want to use Code First migration to seed both users and roles data. The seeding will be done inside the OnModelCreating() method of the Entity Framework DbContext class. To keep things simple, we will use SQLite.

In order to proceed with this tutorial you need to have the following prerequisites:

  • VS Code
  • You have installed .NET 7.0
  • You have installed the dotnet-ef tool

Getting Started

In a terminal window, execute the following command to create an ASP.NET Razor Pages application that supports database authentication using the lightweight SQLite database:

dotnet new razor --auth individual -f net7.0 -o Code1stUsersRoles

Change directory to the newly created folder then run the application:

cd Code1stUsersRoles
dotnet watch

Click on the Register link on the top-right side of your keyboard to add a new user. 


When you click on the Register button, you will receive a page that looks like this:


Click on the link “Click here to confirm your account” to simulate email confirmation. Thereafter, login with the newly created account email and password.

Click on Logout in the top-right corner.

Open the application folder in VS Code.

Create a class named ModelBuilderExtensions in the Data folder of your application. This will contain an extension method to the ModelBuilder class named Seed(). Below is the code for the ModelBuilderExtensions class:

        public static class ModelBuilderExtensions {
    public static void Seed(this ModelBuilder builder) {
        var pwd = "P@$$w0rd";
        var passwordHasher = new PasswordHasher<IdentityUser>();

        // Seed Roles
        var adminRole = new IdentityRole("Admin");
        adminRole.NormalizedName = adminRole.Name.ToUpper();

        var memberRole = new IdentityRole("Member");
        memberRole.NormalizedName = memberRole.Name.ToUpper();

        List<IdentityRole> roles = new List<IdentityRole>() {
           adminRole,
           memberRole
        };

        builder.Entity<IdentityRole>().HasData(roles);

         
        // Seed Users
        var adminUser = new IdentityUser {
            UserName = "aa@aa.aa",
            Email = "aa@aa.aa",
            EmailConfirmed = true,
        };
        adminUser.NormalizedUserName = adminUser.UserName.ToUpper();
        adminUser.NormalizedEmail = adminUser.Email.ToUpper();
        adminUser.PasswordHash = passwordHasher.HashPassword(adminUser, pwd);

        var memberUser = new IdentityUser {
            UserName = "mm@mm.mm",
            Email = "mm@mm.mm",
            EmailConfirmed = true,
        };
        memberUser.NormalizedUserName = memberUser.UserName.ToUpper();
        memberUser.NormalizedEmail = memberUser.Email.ToUpper();
        memberUser.PasswordHash = passwordHasher.HashPassword(memberUser, pwd);

        List<IdentityUser> users = new List<IdentityUser>() {
           adminUser,
           memberUser,
        };

        builder.Entity<IdentityUser>().HasData(users);

        // Seed UserRoles
        List<IdentityUserRole<string>> userRoles = new List<IdentityUserRole<string>>();

        userRoles.Add(new IdentityUserRole<string> {
            UserId = users[0].Id,
            RoleId = roles.First(q => q.Name == "Admin").Id
        });

        userRoles.Add(new IdentityUserRole<string> {
            UserId = users[1].Id,
            RoleId = roles.First(q => q.Name == "Member").Id
        });


        builder.Entity<IdentityUserRole<string>>().HasData(userRoles);
    }
}

Open Data/ApplicationDbContext.cs in your editor. Add the following OnModelCreating() method to the class:

protected override void OnModelCreating(ModelBuilder builder) {
    base.OnModelCreating(builder);

    // Use seed method here
    builder.Seed();
}

In the Program.cs class, replace the call to builder.Services.AddDefaultIdentity statement so that it registers IdentityRole. Replace the entire builder.Services.AddDefaultIdentity statement with the following code:

builder.Services.AddIdentity<IdentityUser, IdentityRole>(
options => {
    options.Stores.MaxLengthForKeys = 128;
})
.AddEntityFrameworkStores<ApplicationDbContext>()
.AddRoles<IdentityRole>()
.AddDefaultUI()
.AddDefaultTokenProviders();

Delete the Data/Migrations folder and the app.db file because we will add new migrations. Thereafter, type the following from a terminal window inside of the root folder of your application:

dotnet ef migrations add M1 -o Data/Migrations

We will apply migrations and update the database with the following command:

dotnet ef database update

Now start the application. To prove that user and role data are successfully seeded, login with one of the below credentials that were previously seeded:

Email Password Role
aa@aa.aa P@$$w0rd Admin
mm@mm.mm P@$$w0rd Member

Add the following above the IndexModel class in Index.cshtml.cs to only allow users that belong to the Member role:

[Authorize (Roles="Member")]

Also, add the following above the PrivacyModel class in Privacy.cshtml.cs to only allow users that belong to the Admin role:

[Authorize (Roles="Admin")]

Only mm@mm.mm is allowed into the / home page and aa@aa.aa is allowed in the /privacy page.

We have succeeded in seeding user and role. Happy Coding.

No comments:

Post a Comment