Fix BlazorServer Identity templates

[JunTaoLuo]

Fixes #25353

[JunTaoLuo]

FYI @jmprieur @javiercn

[jmprieur]

LGTM
Thanks @JunTaoLuo

[JunTaoLuo]

A few notes for reviewers:

1. I verified manually that a blazorserver template with individual auth using local db has now resolved the original issue as described in https://github.com/aspnet/AspNetCore-ManualTests/issues/140. Specifically, now at the email confirmation page:
   
   The links Register and Login now work. For example, after I click Login it directs me to this page:
   

2. In verifying the fix I think I uncovered an issue that current breaks blazorserver template for any configuration (Auth, no auth, etc). Specifically, it seems like @using Microsoft.AspNetCore.Components.Web.Virtualization was added in https://github.com/dotnet/aspnetcore/blame/release/5.0/src/ProjectTemplates/Web.ProjectTemplates/content/BlazorServerWeb-CSharp/_Imports.razor#L7. To my understanding, Virtualization is a purely blazor wasm concern and this using does not belong in a blazor server template. The effect of having such a using statement leads to errors:

C:\gh\tp\BlazorServer\_Imports.razor(7,43): error CS0234: The type or namespace name 'Virtualization' does not exist in the namespace 'Microsoft.AspNetCore.Components.Web' (are you missing an assembly reference?) [C:\gh\tp\BlazorServer\BlazorServer.csproj]

If my understanding is correct, I'm very concerned that this issue wasn't caught earlier

3. I'm a little perplexed by the recommendation in the linked issue:
   The fix would be to use a different set of _LoginPartial files, one for OrgAuth and for IndividualAuth similar to the Razor Pages template: https://github.com/dotnet/aspnetcore/blob/master/src/ProjectTemplates/Web.ProjectTemplates/content/RazorPagesWeb-CSharp/Pages/Shared/_LoginPartial.OrgAuth.cshtml.
   Specifically, the contents of RazorPagesWeb-CSharp/Pages/Shared/_LoginPartial.OrgAuth.cshtml and the original contents of BlazorServerWeb-CSharp/Identity/Pages/Shared/_LoginPartial.cshtml are quite different, such as the content generated for IndividualB2CAuth scenarios. I'm choosing to make the minimum changes to resolve the issue outlined in the original issue https://github.com/aspnet/AspNetCore-ManualTests/issues/140. I'm leaving the option to make further changes to BlazorServerWeb-CSharp/Identity/Pages/Shared/_LoginPartial.cshtml for the next milestone after folks with more context can elaborate on what needs to be updated if any.
   Nevermind, it seems like _LoginPartial is only relevant in IndividualLocalAuth scenarios.

[javiercn]

LGTM

[jmprieur]

LGTM.

Since areas is only used in the IndividualLocalAuth case, maybe just the content of content/BlazorServerWeb-CSharp/Areas/Identity/Pages/Shared/_LoginPartial.cshtml with the content you've proposed for .../content/BlazorServerWeb-CSharp/Areas/Identity/Pages/Shared/_LoginPartial.Identity.cshtml would work?

[JunTaoLuo]

@jmprieur you're absolutely right, It didn't occur to me that we don't need the _LoginPartial.OrgAuth.cshtml at all and I took the recommendation in the issue too literally. However, I'd like to address that for rc2 instead of re-triggering the CI checks again since there's a chance they might not complete before the 10AM deadline. Given the current code is correct but just more verbose than necessary, I'd like to get this change merged as-is.

[Pilchie]

Approved for RC1 if merged before 10am Pacific on 2020-09-01.

[jmprieur]

That sounds good to me, @JunTaoLuo
I tested the patch on my templates, and this works (that's the way I discovered it was not needed)

[jmprieur]

LGTM
Tested

[captainsafia]

Why is this removed?

[JunTaoLuo]

Why was this added in the first place? FYI, I discussed this a little more in #25456 (comment).

[pranavkm]

Virtualization isn't wasm specific, it's part of the core component experience: https://github.com/dotnet/aspnetcore/blob/master/src/Components/Web/src/Virtualization/Virtualize.cs#L12-L18.

It's weird that you're seeing the error. Perhaps you are using an an old targeting pack?

[captainsafia]

Yeah, I believe the template is fine here and this is some environment-related issue. I see this PR is already merged but we should consider bringing it back in another PR. Perhaps @MackinnonBuck can resolve this in his virtualization improvements PR?

[JunTaoLuo]

I'm making a followup PR to this one to rc2 so I'll do it there. Can one of you help me figure out why I was running into the error during verification?