Support finding "sibling" pages when using RedirectToPage and other URL generation sites with relative page names

[DamianEdwards]

Consider a pages folder layout:

~/
  /Pages
    Index.cshtml
    /Account
      Login.cshtml
      Register.cshtml

To redirect from Login.cshtml to Register.cshtml a call like this is made: return RedirectToPage("/Account/Register");. This requires knowledge of the full path to the desired page from the configured pages root.

It would be nice to be able to redirect to pages in the same folder (sibling) without having to know the full page hierarchy like so: return RedirectToPage("Register");. Essentially, the page name passed here is assumed to relative to the current page if it's not qualified with a leading /. If there is a named page with the same name, the sibling page would take precedence over the named page.

This would make it possible to move hives of pages from one place to another and not have to update any of the URL-sensitive code or references within them.

Same logic would of course apply to anywhere we accept page names, e.g. <a asp-page="Register">Click here to register</a>

@rynowak @pranavkm

[rynowak]

The decision here is to implement this in place of the page 'alias' feature. We'll punt aliases to future us.