[Blazor .Net 8 RC2] Not able to register services in Wasm client project

[Ghevi]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Sorry if I've missed any issue talking about this or if I'm messing something up, but as you can try by downloading the repo I've provided, when I register a service in Program.cs of the client project and try to inject it in the Home.razor component page, I get the error that there is no service of that type registered. Here it's says that it should be possible:
https://learn.microsoft.com/en-us/aspnet/core/blazor/fundamentals/dependency-injection?view=aspnetcore-8.0

Expected Behavior

Registering services client side should work

Steps To Reproduce

https://github.com/Ghevi/BlazorApp12

Exceptions (if any)

No response

.NET Version

8.0.100-rc.2.23502.2

Anything else?

No response

[javiercn]

@Ghevi thanks for contacting us.

https://github.com/Ghevi/BlazorApp12/blob/master/BlazorApp12/BlazorApp12.Client/Program.cs#L8

You also need to register it within Program.cs in the host project, as otherwise the page can't be prerendered.

[Ghevi]

@javiercn Thank you! I will try that or disable the prerendering for my wasm component with
IComponentRenderMode Rendermode = new InteractiveWebAssemblyRenderMode(prerender: false);.

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[JasminSAB]

a breaking change with 0 inputs about it ...

[AMUCOMO]

Disabling Prerendering was the thing that I was missing! Setting up a Blazor 8 project, so I can ONLY inject the service in the wasm client, was one think I was unable to do since the .net 8 preview and had me spinning. So to kinda, mirror the "old" .NET hosted WASM Template style. I think especially for the "global-wasm" options in the new template this makes kinda sense. Why would you want to pre-render anything on the sever, when you want to create a all-out-full--wasm-app. Well, sure we could (and the template sets this up) - but that means that all services have to be injected in the server aswell, where their data would also be in the initial state forever in an all wasm app. Anyway thanks for the info, it helped me understand DI in Blazor 8 better! Maybe for the global-wasm option combination prerender should be off by default? Also maybe this piece of info should be boldly presented on the learn-pages imho ;-)

[Bellarmine-Head]

If you are migrating a .NET 6 or 7 Blazor WebAssembly app to .NET 8 and the new Blazor Web App project template, then:

    <Routes @rendermode="new InteractiveWebAssemblyRenderMode(prerender: false)" />

in the server project's App.razor file sorts it (i.e. disable pre-rendering).

To be fair, the official migration guide mentions this (see point 7).

The server project's App.razor file used to be the Client/wwwroot/index.html file.

[JasminSAB]

I really don’t understand why would you remove such template as .net hosted Blazor web assembly - is in your interest to complicate things or to simplify them?

Would it be a lot better approach to still have what we had before and some guides how to achieve more with specific rendering modes?

[Bellarmine-Head]

@JasminSAB - the new Blazor Web App project template is a major step backwards imo... unlike the previous versions, it doesn't even show how the client project can get data from the server project using model classes that are shared between the two; see this issue: #52474

In the new template, the client project "fakes" a data load from the server by waiting for a second or two, and then generates the "downloaded" data itself. Quite frankly, it's embarrassing.

If Microsoft sees a downturn in the take-up of Blazor WebAssembly over the next year or so, this might very well be one of the causes.

Would it be a lot better approach to still have what we had before and some guides how to achieve more with specific rendering modes?

I would love to see a new project template for .NET 8 showing a pure Blazor WebAssembly scenario - like we had before, and showing how the client project gets data from the server project - with some indicators (in in-code comments maybe) as to how one might add other rendering modes later on, if and when you decided you needed them.

[Bellarmine-Head]

To migrate a small .NET 7 Blazor WebAssembly web app to .NET 8 today, I had to use both this guide and a newly-generated Blazor Web App project/solution (with interactivity set to WebAssembly; Global). One of these resources on its own wouldn't have been enough, I had to use both. And without already having an existing Blazor WebAssembly app (originally .NET 5, then migrated to 6, then 7), I wouldn't have had a clue as to how the client project gets data from the server project.

Really and truly, the new-project template should be able to show all this. The fact that it doesn't is pretty bad.