Setting route parameter automatically in ASP.NET Core

Question

Considering the scenario where a specific identifier should be stored after authentication and kept within the path as long as the user is authorized with no need to be specified each time I redirect from the back-end.

To be more specific, When a user signs in, their username (the identifier in this example) is stored as a claim. Now, all of their operations should be under https://example.com/{username}/.....
The problem arising here is that, as far as I know, I need to pass this username each time I generate a URL via the IUrlHelper or redirect through IActionResults.

Does ASP.NET Core provide any standard API for this scenario?
If not, supposing I have to improvise, what are some possible workarounds for this issue?

NOTE: The example above is meant to describe the issue; the reasons behind this method and the benefits it brings are a different story.

Thank you all in advance!

Answer 1

You may try URL rewrite, follow this document

A minimal example:

    public static class MethodRules
    {
        public static void RedirectAuthenticatedUser(RewriteContext context)
        {
            
            var isauthenticated = context.HttpContext.User.Identity?.IsAuthenticated;
            var iscontained = context.HttpContext.Request.RouteValues.ContainsKey("username");
            if (isauthenticated == true&&!iscontained)
            {
                var username = context.HttpContext.User.Identity.Name;
                var request = context.HttpContext.Request;
                var response = context.HttpContext.Response;
                response.StatusCode = (int)HttpStatusCode.MovedPermanently;
                context.Result = RuleResult.EndResponse;
                response.Headers[HeaderNames.Location] =
                    "/"+username + request.Path + request.QueryString;
            }
            
        }
    }

In program.cs:

    ......

    app.UseAuthorization();
    
    var options = new RewriteOptions().Add(MethodRules.RedirectAuthenticatedUser);
    app.UseRewriter(options);
    app.MapControllerRoute(
        name: "default",
        pattern: "{controller=Home}/{action=Index}/{id?}");
    
    app.MapControllerRoute(
        name: "auth",
        pattern: "{username}/{controller=Home}/{action=Index}/{id?}");
    
    app.MapRazorPages();

Result: