Blazor .NET 8 support

[rajsite]

😯 Problem to Solve

We should come up with a plan for .NET 8 support. The Fluent folks made it a breaking change (might mostly be due to a namespace change) and added support for some. NET 8 specific features detailed in a blog

.NET 6 (our current version) goes out of active support in November 2024.

Here is a Teams thread discussing versions that existing clients use.

📋 Tasks

• Create HLD - HLD: Blazor .NET 8 support #2411
• Update Nimble / Spright Blazor to .NET 8 #2454 :
  • Update TargetFramework from net6.0 to net8.0 for all BlazorWorkspace.sln projects
  • Update Microsoft.AspNetCore.Components.Web reference from 6.x to 8.x for all BlazorWorkspace.sln projects
  • Unpin analyzer versions (NI.CSharp.Analyzers, from [2.0.21]), update to latest - see Newer NI.CSharp.Analyzers 2.0.25 causes Nimble Blazor build issue #2014
  • Update examples: Re-build Demo.Server example app off of new "Blazor Web App" template ("Blazor Server App" template is now deprecated / cannot be targeted to .NET 8). Evaluate if Demo.Client/Demo.Server should be merged. Ensure Demo.Hybrid still works as expected.
  • Update NimbleBlazor and SprightBlazor README.md - location to add Nimble/Spright imports changed (no longer _Layout.cshtml for Blazor Server/ Web App variant, now App.razor)
  • Other doc updates (including CONTRIBUTING, updating SDK version references). Document supported Blazor render modes.
  • Evaluate that Playwright tests are written to sufficiently test .NET 8 apps. For example our existing tests didn't catch the issue above.
  • Blazor EventCallbacks are not invoked with apps using .NET 8 template #2355
• Fix all errors/warnings: ~72 to resolve. Most common 3 are IDE0290 (Use primary constructor), IDE0028 (Collection initialization can be simplified), IDE0090 (new expression can be simplified). Alternatively suppress to start with, and create separate tech debt / PR to address fully. : Split off to Fix / re-evaluate Blazor disabled code analysis rules #2453
• Further investigations on Possible race condition showing Blazor NimbleDialog during OnAfterRenderAsync #2188 (which may be specific to .NET 8)

Before completing this work, we also want to check the upgrade status of our Blazor clients to see if they're ready to uptake a .NET 8 NimbleBlazor.