Blazor SSR - RemoteNavigationManager should be made public

[darbrius]

Is there an existing issue for this?

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Is your feature request related to a problem? Please describe the problem.

I am attempting to verify if a NavigationManager has been initialized prior to utilizing it in a Blazor SSR app using .NET8. I attempted to cast it to a RemoteNavigationManager and found that due to it being internal I am unable to do so and thus cannot verify if the JsRuntime has been initialized and bound.

Describe the solution you'd like

I would like RemoteNavigationManager to be made public.

Additional context

No response

[javiercn]

@darbrius thanks for contacting us.

You don't have to worry about NavigationManager or any other framework provided service. The host takes care of initializing them.

RemoteNavigationManager is an implementation detail and making it public will constraint our future development choices, so it's not something we plan to do.

[darbrius]

@javiercn Would it be possible to expand the API for NavigationManager to have an IsInitialized flag then?

It feels awkward that we know the navigation manager could throw an error and have to prepare extra handling for that case, whereas with access to a flag we could safely verify and handle it in that case without having to follow an exception flow.

[javiercn]

It feels awkward that we know the navigation manager could throw an error and have to prepare extra handling for that case, whereas with access to a flag we could safely verify and handle it in that case without having to follow an exception flow.

NavigationManager throws an exception in 9.0 and earlier releases during prerendering. This is something we are changing in 10.0

Having a flag doesn't help at all because for example on Interactive Server render mode, you could check the flag, the connection might go down after it and an exception will happen.

The recommendation is that you always wrap calls in a try..catch (same as JS interop) to handle this situation.

The other case where you might get an exception is when you resolve the NavigationManager from a different scope. The best way to avoid this is to pass the navigation manager around instead of injecting an instance if your code might run in a separate scope.

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