Generating an absolute URL while ignoring all ambient values

Is there a simple way to generate an URL to the current Razor page, while ignoring all ambient values?

Let’s assume I’m on a Razor page Foo that has an optional route parameter id, @page {id?}. So my current URL is http://localhost:5000/Foo/Bar. Now I want to generate a link to that same Razor page but without the id. The desired result would be http://localhost:5000/Foo.

All my attempts to use the IUrlHelper failed because it will always reuse the ambient values, even when I specify an explicit RouteValueDictionary. That’s because the UrlHelper will eventually use the link generator to create an address, and that will always extract the ambient values first.

The only way I got this to work now is the following:

public static string GetPageUri(this HttpContext httpContext, string page)
{
    var linkGenerator = httpContext.RequestServices.GetService<LinkGenerator>();
    var values = new RouteValueDictionary
    {
        ["page"] = page,
    };
    return linkGenerator.GetUriByAddress(httpContext, new RouteValuesAddress
    {
        ExplicitValues = values,
    }, values);
}

So I use the link generator and the most low-level function it offers to create an URI by a RouteValuesAddress where I explicitly leave out the ambient values.

Am I missing something or is there really no way to generate a link like that from the UrlHelper directly? I am aware that reusing ambient values for the same page is completely per design but there should still be some way to opt out of this, or not?

[javiercn]

@poke I see.

I’m going to close the issue for now as the question has been answered. I’ll let @rynowak comment on the fragment below if he has any further thoughts and we can potentially open a separate issue if necessary to track any remaining work.

I would want this on the UrlHelper, so that I can use it directly within a view without having to retrieve a link generator.

[rynowak]

That’s good. The UrlHelper does feel a bit old at times.

Super yes. The problem is that we have many many experiences that are layered on top of it, and these areas are super touchy.