Razor runtime recompilation does not seems to work with *.razor component files

Question

I'm testing the new Razor Components (aka. Server Side Blazor) and I'm finding the need to stop the project, edit, recompile and restart the server, very time consuming. I want to edit the *.razor files, save, press F5 on the browser, and done.

I know there is a breaking change on ASP.NET Core 3, that prevented this from happening for a while. But now, there is a "fix": you just need to install the package Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation, and setup the service like that:

services.AddMvc()
.AddRazorRuntimeCompilation();

(Yes, without Mvc, see this)

But that does not seems to work - at least, I did not try with cshtml files, since I am only using *.razor in my tests.

I also did:

services.AddMvc()
.AddRazorRuntimeCompilation((options) =>
{
    foreach (var item in Directory.GetFiles(Directory.GetCurrentDirectory(), "*.razor", SearchOption.AllDirectories))
    {
        options.AdditionalReferencePaths.Add(item);
    }
});

Without any luck.

Is this not yet supported or I am doing something wrong?

Repp

I don't think this actually applies to Razor components. It's talking about view compilation. Razor components are actually rendered into an in-memory DOM representation, which by the sound of it, seems like it would be tricky to alter every time you make a change in a *.razor file. Rebuilding has the effect of dump the in-memory tree, so it is then recreated (thus applying your update). You might be better served by actually asking this question in a issue on the Github project page. – Gleaning

Found it: github.com/aspnet/AspNetCore/issues/8071 – Repp

Hey. What do you know. My guess was pretty much correct. Although, the bit about dotnet watch, I hadn't considered. That should work for you. You still have to rebuild, but that will effectively automatically kick off the build for you. – Gleaning

@ChrisPratt exactly. However, the main problem for me is loosing the application state. But this is better than nothing, I guess.. – Repp

Razor Components does not seem to be "stateless", and I guess that if I manage to maintain the Browser open (trying to maintain the state) between builds, it will break stuff – Repp

Yes. It's definitely not stateless. Essentially, it's creating a server-side approximation of the client-side DOM. Obviously, for that to work, the two need to be in sync. If the it loses the state server-side, then nothing is right. – Gleaning