[Blazor] Attempting to navigate to URI with fragment causes Microsoft.AspNetCore.Components.NavigationException server-side

[xperiandri]

Describe the bug

Attempting to navigate to address with fragment like https://localhost:44317/product/abc#General-information in server-side Blazor causes Microsoft.AspNetCore.Components.NavigationException

To Reproduce

1. Using this version of ASP.NET Core 3.0 RTM
2. Create a page with a button that navigates to the same URI but with a fragment

protected override void OnInitialized()
{
    var uri = new Uri(navigationManager.Uri);
    var fragment = uri.Fragment;
    if (fragment != "#fragment")
        navigationManager.NavigateTo(GenerateTabLink("#fragment"));
    else
        selectedTab = fragment;
}
private string GenerateTabLink(string tabFragment)
{
    var builder = new UriBuilder(new Uri(navigationManager.Uri, UriKind.RelativeOrAbsolute))
    {
        Fragment = tabFragment
    };
    return builder.ToString();
}

3. See error Microsoft.AspNetCore.Components.NavigationException

Expected behavior

Component navigates to the same page with the added fragment

[xperiandri]

Ah, I got it. navigationManager.Uri return URL without fragment. But URL in browser contains a fragment. This way navigation happens to the same URL.

[mkArtakMSFT]

Thanks for contacting us, @xperiandri.
Can you please share a complete sample app (ideally as a GitHub repo) so that we can investigate it?

[kmuthukumar23]

Hi @mkArtakMSFT

I am also facing the same issue when using the Urihelper.

I have switched to 'Release' mode, then it works perfectly. But i have no idea about how it is worked in 'Release' and not work in 'Debug' mode.

Any thoughts regard this?

[mkArtakMSFT]

@kmuthukumar23 please provide a minimal repro project, so we can investigate this.

[kmuthukumar23]

Hi @mkArtakMSFT

Here is the Sample.

navIssue.zip

Steps to reproduce:

1. open the project in vs 2019 preview
2. Run it.
3. It will throws the following
   

i have used vs 2019 16.4 preview 1 and .net core 3.0.100

[mkArtakMSFT]

@javiercn is this something you have context about?

[javiercn]

@kmuthukumar23 I can't repro this behavior with your repro. I'm using RTM bits, is there any special url you are using?

[kmuthukumar23]

Hi @javiercn

I have just set the initial loading URL in 'index.razor' by using 'UriHelper'. In default blazor app, it navigates to 'pages/index.razor'. Now i am override it to navigate to 'pages/counter.razor' by using 'UriHelper' in 'index.razor'.

in index.razor, i have modified like below.

@using Microsoft.AspNetCore.Components

@Inject Microsoft.AspNetCore.Components.NavigationManager UriHelper

Hello, world!

Welcome to your new app.

@code{

protected override void OnInitialized()
{
    UriHelper.NavigateTo("Counter");
}

}

[javiercn]

That works for me without issue. I’m using RTM bits

[kmuthukumar23]

Hi @javiercn

I have attached video for this. Please check it.

https://drive.google.com/file/d/1-0MhbpapthHneN4GkTP1Br9XWidl38gZ/view?usp=sharing

[javiercn]

@kmuthukumar23 That exception is expected, that's how the component signal that a redirection needs to happen.

You have first chance exceptions turned on, that's why you are seeing the debugger break on the exception. If you press F5 you'll see that you are correctly redirected to the /counter page and that it gets rendered successfully.

You can configure the debugger to avoid breaking on this exception as follows:

[javiercn]

@kmuthukumar23 Thanks for the video showcasing your issue.

We've determined that this behavior is by design, follow the instructions above to avoid breaking on this exception type.

We are closing this issue as the behavior is by design and there's no further action to be taken here.