How to access other entities from ASP.NET Core Identity classes? - asp.net-core

Question

New to ASP.NET Core. I'm using the Identity framework for authentication, scaffolding among other the Register razor page. In the Register.cshtml.cs, I'd like to get data for populating a dropdown menu. The data is in another part of the Entity Framework tables. So the intention is to be able to select e.g. "Company" when registering a user.
I don't like too fiddle to much with the Register.cshtml.cs, i.e. modifying the constructor to take my own services and/or context objects. But how to access "my own" tables from within that page?
Can it be done? Or shouldn't it be done (why?)? And if not, any advice on making this general user admin stuff in combination with the Identity framework?
Thanks,
Palle

Answer 1

The ASP.NET Core Identity is used to manage users, passwords, profile data, roles, claims, tokens, email confirmation, and more. We can use the UserManager, RoleManager and SignInManager to manage the following tables:
More detail information about Identity, see Identity on ASP.NET Core.
To access other Entity Framework tables, I think you have to use the database context in the Register.cshtml.cs, like this:
public class RegisterModel : PageModel
{
private readonly SignInManager<ApplicationUser> _signInManager;
private readonly UserManager<ApplicationUser> _userManager;
private readonly ILogger<RegisterModel> _logger;
private readonly IEmailSender _emailSender;
private readonly ApplicationDbContext _context;
public RegisterModel(
UserManager<ApplicationUser> userManager,
SignInManager<ApplicationUser> signInManager,
ILogger<RegisterModel> logger,
ApplicationDbContext context,
IEmailSender emailSender)
{
_userManager = userManager;
_signInManager = signInManager;
_logger = logger;
_context = context;
_emailSender = emailSender;
}
[BindProperty]
public InputModel Input { get; set; }
public string ReturnUrl { get; set; }
[BindProperty]
public List<Company> Companies { get; set; }
public IList<AuthenticationScheme> ExternalLogins { get; set; }
public class InputModel
{
...
}
public async Task OnGetAsync(string returnUrl = null)
{
ReturnUrl = returnUrl;
ExternalLogins = (await _signInManager.GetExternalAuthenticationSchemesAsync()).ToList();
Companies = _context.Companies.ToList(); //get all companies from database.
}
Besides, if you still don't want to use the DB context. You could consider setting the select items with fixed options list or using an enumeration list, without getting them from the database.