mvc4 PartialView solution is needed - asp.net-mvc-4

Question

im building a site using MVC4 and i want to display a navigation bar at the top of my _ViewStart according to my Database.
How can i do so? can i use a contoroller ActionResult that fired once the index page is loaded?
or how can i triger it by a partial view
my current ActionResult returning partial view is:
public ActionResult NavigationBar()
{
var entities = new CakesDBEntities();
var articles = entities.Articles;
List<NavBarModel> navBarList = articles.Select(nb => new NavBarModel { Title = nb.title, Url = nb.url }).ToList();
return View(navBarList);
}
my model:
namespace SimplyCakes20131009.Models
{
public class NavBarModel
{
public string Title { get; set; }
public string Url { get; set; }
}
}
my partial view:
#model IEnumerable<SimplyCakes20131009.Models.NavBarModel>
#foreach (var bar in Model)
{
<li>
#Html.ActionLink(bar.Title, bar.Url)
</li>
}
How can i integrate the nav bar to my _ViewStart?

Answer 1

A better option would be to use the _Layout.cshtml. _ViewStart is just calls the _Layout.cshtml.
You probably don't need partial View here. You can use a Child Action that renders PartialView results.
In your
_Layout.cshtml :
You can have
#{ Html.RenderAction("Navigation", "Home"); }
This points to the HomeController and Navigation Action
Additional Note: Html.RenderAction better because it is much faster than the Html.Action.
It can handle large amount of HTML efficiently as it will directly send the result to the Response. Html.Action just returns a strings with the result.
Navigation Action has its Navigation View which is pretty much equivalent to what you had in your view.
Home/Navigation.cshtml :
#model IEnumerable<MvcApplication1.Controllers.NavViewModel>
#foreach (var nav in Model)
{
<li>#Html.ActionLink(nav.Title, nav.Url)</li>
}
HomeController.cs :
Note that you probably inject the DB access as dependency to support the testability.
public class HomeController : Controller
{
private readonly ICakesRepository _cakesRepository;
//additional constructor to support testability.
public HomeController(ICakesRepository cakesRepository) {
_cakesRepository = cakesRepository;
}
//this can be removed if you the above with IOC/DI wire-up
public HomeController() {
_cakesRepository = new CakesRepository();
}
[ChildActionOnly]
[HttpGet]
public ActionResult Navigation() {
var articles = _cakesRepository.GetArticles();
var navBarList = articles.Select(nb => new NavViewModel { Title = nb.Title, Url = nb.Url });
return PartialView(navBarList);
}
}
Additional supporting classes :
public class NavViewModel {
public string Title { get; set; }
public string Url { get; set; }
}
public interface ICakesRepository {
IEnumerable<Articles> GetArticles();
}
public class CakesRepository : ICakesRepository {
public IEnumerable<Articles> GetArticles() {
//call to a db
//fake db data
return new List<Articles>() {
new Articles(){Title = "Title1", Url = "http://urlone.com"},
new Articles(){Title = "Title2", Url = "http://urltwo.com"},
new Articles(){Title = "Title3", Url = "http://urlthree.com"}
};
}
}
public class Articles {
public string Title { get; set; }
public string Url { get; set; }
}