asp.net mvc 5 page show/hide/access based on table value - asp.net-mvc

Question

Please see code below that creates menu items. Now how can I show/hide/access a menu item that is created as below. Also I want to make sure user do not directly access page. I want to do this based on value in one my table( no default table). I know we can use [Authorize(Roles = "Admin")] based on roles, but like I mentioned I want to manually look for a value in a custom table then show/hide/allow access of page.
Thanks.
<div class="navbar-collapse collapse">
<ul class="nav navbar-nav">
<li>#Html.ActionLink("Roles", "Index", "AspNetRoles", new { }, new { #style = "color:#21ce99;" }) </li>
<li>#Html.ActionLink("Users", "Index", "AspNetUsers", new { }, new { #style = "color:#21ce99;" })</li>
<li>#Html.ActionLink("User Groups", "Index", "UserGroupRoles", new { }, new { #style = "color:#21ce99;" })</li>
</ul>
#Html.Partial("_LoginPartial")
</div>
Note: After getting help from Stephen ,I managed to write below code. But now I am getting error
"The controller for path '/' was not found or does not implement IController."
Controller Code
using System.Web.Mvc;
using .Models;
namespace TestProj.Controllers
{
public class NavigationVMController : Controller
{
[ChildActionOnly]
public ActionResult Navigation()
{
NavigationVM NavItems = new NavigationVM();
NavItems.CanViewRoles = true; //setting all true temporarily for testing
NavItems.CanViewUsers = true;
NavItems.CanViewUserGroups = true;
//return View(Alex);
return View("_Navigation", NavItems);
}
// GET: NavigationVM
public ActionResult Index()
{
return View();
}
}
}
Model Code
namespace TestProj.Models
{
public class NavigationVM
{
public bool CanViewRoles { get; set; }
public bool CanViewUsers { get; set; }
public bool CanViewUserGroups { get; set; }
}
}
Partial view Code
#model TestProj.Models.NavigationVM
<div class="navbar-collapse collapse">
<ul class="nav navbar-nav">
#if (Model.CanViewRoles)
{
<li>#Html.ActionLink("Roles", "Index", "AspNetRoles", new { }, new { #style = "color:#21ce99;" }) </li>
}
<li>#Html.ActionLink("Users", "Index", "AspNetUsers", new { }, new { #style = "color:#21ce99;" })</li>
<li>#Html.ActionLink("User Groups", "Index", "UserGroupRoles", new { }, new { #style = "color:#21ce99;" })</li>
</ul>
#Html.Partial("_LoginPartial")
</div>
Calling code from _Layout.cshtml
#Html.Action("Navigation", "NavigationVMController")

Answer 1

Create a partial view for the navigation links and call a ChildActionOnly method that initializes a view model based on some parameters that you can use to conditionally check which links should be displayed
View model
public class NavigationVM
{
public bool CanViewRoles { get; set; }
public bool CanViewUsers { get; set; }
public bool CanViewUserGroups { get; set; }
}
Controller (probably in a BaseController so its available everywhere
[ChildActionOnly]
public ActionResult Navigation
{
NavigationVM model = new NavigationVM();
model.canViewRoles = ?? // call a service which returns the value based on the current user
....
return PartialView("_Navigation", model)
}
Partial View (_Navigation.cshtml)
#model yourAssembly.NavigationVM
<div class="navbar-collapse collapse">
<ul class="nav navbar-nav">
#if (Model.CanViewRoles)
{
<li>#Html.ActionLink("Roles", "Index", "AspNetRoles", new { }, new { #style = "color:#333;" })</li>
}
.... // ditto for CanViewUsers and CanViewUserGroups
</ul>
</div>
and in the main view or layout
#Html.Action("Navigation") // renders the navigation links
#Html.Partial("_LoginPartial")
This will only display the appropriate links, but of course a user could still type in the address to try and access the pages so your controller methods still need to perform validation
AspNetRolesController
public ActionResult Index()
{
// Check permissions based on user
bool canView = ?? // call a service which returns the value based on the current user
if (!canView)
{
return new HttpUnauthorizedResult();
}
....
}