Question

I’m working on a custom implementation of ASP.NET membership, which uses my own database tables. Everything works as it should, but I need to redirect customers, which have not paid their invoice, to a payment page. This should not only happen on login, but also for users which already are logged in, so if an invoice is registered as “not paid” while the user is logged in, then the user must be redirected to the payment page, the next time they load a page.

Can this be done?

Answer 1

I did something similar to this using a HttpModule. What you want to do is handle the PreRequest event and if they are authenticated and if so make your unpaid invoice check and redirect as necessary.

e.g.

protected void OnPreRequestHandlerExecute(object sender, EventArgs e)
{
    if (HttpContext.Current.Request.Path != "/UnPaid.aspx" && HttpContext.Current.User != null)
        {
            if (HttpContext.Current.User.Identity.IsAuthenticated)
            {
                // You don't want to make this check for every resource type
                bool isPage = HttpContext.Current.Request.Path.EndsWith(".aspx") || HttpContext.Current.Request.Path == "/";
                if (isPage)
                {
                    bool isPaid = false; // Make isPaid check here
                    if (!isPaid)
                    {
                        // Optional pass ina return url for after the invoice is paid
                        string returnUrl = HttpUtility.UrlEncode(HttpContext.Current.Request.RawUrl, HttpContext.Current.Request.ContentEncoding);

                        HttpContext.Current.Response.Redirect(string.Concat("/UnPaid.aspx?ReturnUrl=", returnUrl), true);
                    }
                }
            }
        }
    }