How to change a URL Link in ASP.NET MVC Breadcrumb

How to change a URL Link in ASP.NET MVC Breadcrumb

Problem Description:

I found a nice answer on creating breadcrumbs for this project here:

How can dynamic breadcrumbs be achieved with ASP.net MVC?

The modified code that I am using is here:

public static string BuildBreadcrumbNavigation(this HtmlHelper helper)
{
    var result = string.Empty;
    var controllerName = helper.ViewContext.RouteData.Values["controller"].ToString();
    if ((controllerName != "Home") && (controllerName != "Account"))
    {
        var htmlLink = helper.ActionLink(
            linkText: "Home",
            actionName: "/",
            controllerName: "Home").ToHtmlString();

        var sb = new StringBuilder($"<ol class='breadcrumb'><li>{htmlLink}</li>");

        var controllerLink = helper.ActionLink(
            linkText: controllerName,
            actionName: "/",
            controllerName: controllerName);

        sb.Append($"<li>{controllerLink}</li>");

        var actionName = helper.ViewContext.RouteData.Values["action"].ToString();

        var actionLink = helper.ActionLink(
            linkText: actionName,
            actionName: actionName,
            controllerName: controllerName);

        sb.Append($"<li>{actionLink}</li>");

        result = sb.Append("</ol>").ToString();
    }
    return result;
}

The webpage I want to implement it on has a navigation menu:

• Services
  • Parts
  • Bulletins
  • Publications
  • Warranty
• Sales
  • Buyers
  • Image Resources
  • Videos

For something like Home > Services > Parts, there is a controller called ServiceController.cs and a model called PartsInformation.cs.

The links for Home and Parts work fine, but there is nothing to display for the intermediate Services because it is a menu item only. Clicking Services attempts to redirect here:

https://localhost:44383/Services/

What should be done here?

Should I remove the link for Services and leave the text, or should I have Services route to Home?

I would like to route the root navigation menu items back to Home, but I don’t understand enough about this ActionLink.

Solution – 1

Here is what I have done until someone posts a better solution:

In the file Global.asax.cs, I added the Application_Error method to redirect when a controller is not found:

protected void Application_Error()
{
    var err = Server.GetLastError();
    if (err.GetType() == typeof(InvalidOperationException))
    {
        if (err.Message.IndexOf("The view 'Index' or its master was not found") == 0)
        {
            if (-1 < err.StackTrace.IndexOf("System.Web.Mvc.ViewResult.FindView(ControllerContext context)"))
            {
                // this controller does not have a view
                var request = HttpContext.Current.Request;
                var homeLink = $"{request.Url.Scheme}://{request.Url.Authority}{request.ApplicationPath.TrimEnd('/')}/";
                Response.Redirect(homeLink);
            }
        }
    }
}

It works, but it just doesn’t seem like the way ASP.NET MVC should handle the case of links going to controllers that do not exist.

Solution – 2

https://localhost:44383/Services/

It is trying to redirect to default action of ServiceController, which is typically named Index.

I think you have a few options (depending on what you want):

1. Redirect to /Home:

   public class ServiceController : Controller
   {
       // assuming you want to redirect to HomeController's default action:
       public IActionResult Index() => Redirect("/Home");
   
       // or if you know HomeController's default action name,
       // you can use more idiomatic syntax:
       //
       // public IActionResult Index() => RedirectToAction("Index", "Home");
   }
   

2. Utilize this space by adding an action Index page under Services (with list of services).

3. Render Services in breadcrumb as text (instead of link):

   if (controllerName == "Services")
   {
       sb.Append($"<li>{controllerName}</li>");
   }
   else
   {
       var controllerLink = helper.ActionLink(
           linkText: controllerName,
           actionName: "/",
           controllerName: controllerName);
   
       sb.Append($"<li>{controllerLink}</li>");
   }
   

(I’d personally choose option #2 if it’s my decision)