Notes for asp.net mvc 4 in action

mvc4inAction

//Server side
public ViewResult Show(int id)
{
    var entry = _db.Entries.Find(id);
    bool hasPermission = User.Identity.Name == entry.Name;
    ViewData["hasPermission"] = hasPermission;
    return View(entry);
}

//View
<p>
    @{
        bool hasPermission = 
            (bool) ViewData["hasPermission"];         
    }
    @if (hasPermission)
    {
        @Html.ActionLink("Edit", "Edit", 
            new {id = Model.Id})                  
    }
    @Html.ActionLink("Back to Entries", "Index")      
</p>

ViewData Dictionary syntactically it isn’t very nice to work with—you have to perform type casts
whenever you want to retrieve something from the dictionary.

ViewBag approach:

//Controller
ViewBag.HasPermission = hasPermission;

//View
<p>
    @if (ViewBag.HasPermission)
    {
      @Html.ActionLink("Edit", "Edit", new {id = Model.Id})
    }
    @Html.ActionLink("Back to Entries", "Index")
</p>




The  generic WebViewPage<T> inherits from WebViewPage but offers some unique additions not avail-
able in the nongeneric WebViewPage class.

public class WebViewPage<TModel> : WebViewPage
{
    public new AjaxHelper<TModel> Ajax { get; set; }
    public new HtmlHelper<TModel> Html { get; set; }
    public new TModel Model { get; }                        
    public new ViewDataDictionary<TModel> ViewData { get; set; }
}

See ? There are some strongly typed object.



//List inside controller
public ActionResult Index()
{
    var mostRecentEntries = (from entry in _db.Entries
                             orderby entry.DateAdded descending
                             select entry).Take(20);
    var model = mostRecentEntries.ToList();
    return View(model);
}

//List object in view
@using Guestbook.Models
@model List<GuestbookEntry>

//
public class LogOnModel
{
    [Required]                                        
    [Display(Name = "User name")]                     
    public string UserName { get; set; }

    [Required]                                        
    [DataType(DataType.Password)]                     
    [Display(Name = "Password")]                      
    public string Password { get; set; }

    [Display(Name = "Remember me?")]
    public bool RememberMe { get; set; }
}