No service for type 'UserManager<IdentityUser>' has been registered. about aspnetcore.identity.mongodbcore

[MisinformedDNA]

Right, it says

Your user and role entities must inherit from MongoIdentityUser and MongoIdentityRole

but it doesn't call out that MongoIdentityUser doesn't inherit from IdentityUser, nor does it call out that the partial needs to be updated. These should be called out in the README.

That's why I converted the MVC sample that was in the MSFT repo

Samples are nice, but is it your intention that we copy your sample as a starting point? Maybe that works fine for MVC, but that leaves out people who are developing Razor Pages or Blazor apps. Because of that, the README should call out the bare minimum to get started, regardless of project type.

[MisinformedDNA]

I figured it out, though I don't like the solution...

First IdentityUser is used in all the default Identity templates, so, by default, _LoginPartial.cshtml is looking for a binding to UserManager<IdentityUser> and no matching service could be found.

Looking at the inheritance chain, I found that

• MongoIdentityUser inherits from IdentityUser<Guid>
• IdentityUser inherits from IdentityUser<string>

So that explains why this error keeps showing up: MongoIdentityUser doesn't actually inherit from IdentityUser.

I don't know how you can clearly communicate this through code, so at the very least, the documentation should show how to convert a default Identity template to use this provider instead.

[alexandre-spieser]

Hello thanks for your message. Not sure what the issue is here.
the documentation should show how to convert a default Identity template to use this provider instead. <= That's why I converted the MVC sample that was in the MSFT repo :
https://github.com/alexandre-spieser/AspNetCore.Identity.MongoDbCore/tree/b3db4eb39fcd2d1f0df59ffbb6933dc53f794476/sample/MongoIdentitySample.Mvc.

Where the partial is indeed different:
https://github.com/alexandre-spieser/AspNetCore.Identity.MongoDbCore/blob/master/sample/MongoIdentitySample.Mvc/Views/Shared/_LoginPartial.cshtml

@inject SignInManager<ApplicationUser> SignInManager
@inject UserManager<ApplicationUser> UserManager

UserManager<IdentityUser> cannot work in this package.
As mentioned in the docs:

Your user and role entities must inherit from MongoIdentityUser<TKey> and MongoIdentityRole<TKey> in a way similar to the IdentityUser<TKey> and the IdentityRole<TKey> in Microsoft.AspNetCore.Identity, where TKey is the type of the primary key of your document.

If you really want string primary keys:

public class ApplicationUser: MongoIdentityUser<string>
{
	public MyUser () : base()
	{
	}

	public MyUser (string userName, string email) : base(userName, email)
	{
	}
}

with matching role:

public class ApplicationRole : MongoIdentityRole<string>
{
	public ApplicationRole() : base()
	{
	}

	public ApplicationRole(string roleName) : base(roleName)
	{
	}
}

then:

services.AddIdentity<ApplicationUser, ApplicationRole>()
	.AddMongoDbStores<ApplicationUser, ApplicationRole, string>
	(
		"mongodb://localhost:27017",
		"MongoDbTests"
	)
	.AddDefaultTokenProviders();

As highlighted in:
https://github.com/alexandre-spieser/AspNetCore.Identity.MongoDbCore#user-and-role-entities

If you feel like the docs are not clear enough please feel free to raise a PR. I understand your frustration but unfortunately I cannot satisfy everyone. I advise you to copy the sample and use it as a boiler plate for your project to avoid issues.

I hope this makes sense.