Logged user based connection string in .NET Core - .net-core

Question

I have an application that uses identity database to store users and customers.
Each customer has also a separate database with its data and its connection string is stored in Customer table in the identity database.
AspNetUsers has a field to tell which customer the user belongs to (also identity db).
I want to assign connection string to the user when he logs in and make it available in the application for the duration of the session.
I currently have customer model:
public partial class `Customer`
{
public int Id { get; set; }
public string Name { get; set; }
public int NoLicenses { get; set; }
public bool? Enabled { get; set; }
public string CustomerConnectionString { get; set; }
}
and user model:
public class ApplicationUser : IdentityUser
{
public string CustomerId { get; set; }
public bool? IsEnabled { get; set; }
// there ideally I'd have a connstring property
}
The models map db table fields.
I'm using .NET Core 1.1 and EF Core.

Answer 1

With the defalut ASP.NET Identity template , you can :
extend the ApplicationUser class in Models folder :
public class ApplicationUser : IdentityUser
{
public string CustomerId { get; set; }
public bool? IsEnabled { get; set; }
//add your custom claims
public string CustomerConnectionString { get; set; }
}
Add your custom model to ApplicationDbContext in Data folder :
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
: base(options)
{
}
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
// Customize the ASP.NET Identity model and override the defaults if needed.
// For example, you can rename the ASP.NET Identity table names and more.
// Add your customizations after calling base.OnModelCreating(builder);
}
public DbSet<Customer> Customers { get; set; }
}
Sync your database : Add-Migration xxxx , then run the Update-Database command in Package Manager Console . Now you have the Customer table and have CustomerConnectionString column in AspNetUsers table.
Create you own implementation of IUserClaimsPrincipalFactory by inheriting the default one to generate a ClaimsPrincipal from your user :
public class AppClaimsPrincipalFactory : UserClaimsPrincipalFactory<ApplicationUser, IdentityRole>
{
public AppClaimsPrincipalFactory(
UserManager<ApplicationUser> userManager
, RoleManager<IdentityRole> roleManager
, IOptions<IdentityOptions> optionsAccessor)
: base(userManager, roleManager, optionsAccessor)
{ }
public async override Task<ClaimsPrincipal> CreateAsync(ApplicationUser user)
{
var principal = await base.CreateAsync(user);
if (!string.IsNullOrWhiteSpace(user.CustomerId))
{
((ClaimsIdentity)principal.Identity).AddClaims(new[] {
new Claim("customid", user.CustomerId)
});
}
if (!string.IsNullOrWhiteSpace(user.CustomerConnectionString))
{
((ClaimsIdentity)principal.Identity).AddClaims(new[] {
new Claim("CustomerConnectionString", user.CustomerConnectionString)
});
}
return principal;
}
}
Register the custom factory you just created in your application startup class, after adding Identity service:
// Add framework services.
services.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
services.AddIdentity<ApplicationUser, IdentityRole>()
.AddEntityFrameworkStores<ApplicationDbContext>()
.AddDefaultTokenProviders();
services.AddScoped<Microsoft.AspNetCore.Identity.IUserClaimsPrincipalFactory<ApplicationUser>, AppClaimsPrincipalFactory>();
Then you could access the claims like :
var connectString = User.Claims.FirstOrDefault(c => c.Type == "CustomerConnectionString").Value;
Modify the creating/editing user view/controller , add the customer dropdownlist on view , get the custom id in Register function in AccountController , query the connectingString of custom from db , and save in ApplicationUser object :
var user = new ApplicationUser { UserName = model.Email, Email = model.Email };
var result = await _userManager.CreateAsync(user, model.Password);