Question

I want to display a message in layout coming from child action ? How can i do that ?
Like in my layout i have a login form (rendered as a child action).. so when the login fail i would like to show a message in the layout in a specific DIV. The problem is that the layout is probably rendered before the child view. Also there another problem, the layout is rendered by any controller. Any ideas ?

Answer 1

You could put a validation summary in your layout somewhere. (Razor syntax):

<div>@Html.ValidationSummary(false)</div>

Then just decorate the viewmodel that is being passed to your login with [Required] attributes.

public class LoginViewModel
{
    [Required(ErrorMessage="Please enter a your user name.")]
    public string UserName { get; set; }

    [Required(ErrorMessage = "Please your password.")]
    public string Password{ get; set; }
}

or if you wanted to put a more general error message just leave your viewmodel properties decorated with the [Required] attribute, then in your Login controller, in the POST method do something like this:

[HttpPost]
public ActionResult Login(LoginViewModel viewModel)
{
    if (!ModelState.IsValid)
    {
        ModelState.AddModelError("Error", "Sorry, your login failed, please try again.");
    }
}

that error will then show up in the validation summary.