How to use Linq objects to validate a view in MVC 2

Question

Hi

I would like to use Linq and strongly typed views in the right way. at the moment I do the following:

Make a Model to verify agianst:

public class Menu
    {
        public int Id { get; private set; }
        public string Text { get; private set; }
        public string Action { get; private set; }
        public string Controller { get; private set; }
        public string Parameter { get; private set; }
        public string Langue { get; private set; }

        public Menu(int id, string controller, string action, string parameter, string text)
        {
            Id = id;
            Controller = controller;
            Action = action;
            Text = text;
            Parameter = parameter;
        }

Use Linq to get the data from the database into the model:

public static List<Menu> GetTabListForMenu(string langue)
{
    Page_dbEntities entity = new Page_dbEntities();


   var tabList = (from ml in entity.wpmenulangue
                   where ml.Langue == langue
                   from m in entity.wpmenu
                   where ml.Menu == m.Id
                   from l in entity.wplangue
                   where ml.Langue == l.Langue
                   from p in entity.wppage
                   where p.Id == m.Page
                   select new { m.Id, p.Controller, p.Action, p.Parameter, ml.Text}).ToList();

    List<Menu> menu = new List<Menu>();
    foreach (var item in tabList)
    {
        menu.Add(new Menu(item.Id, item.Controller, item.Action, item.Parameter, item.Text));
    }
    return menu;
}

I am pretty convinced that this is not the optimal way to do this and have 2 questions:

1. When I get the data from the database I first use a var and then have to move it to the object with a foreach. this seems like a waste of both my time and less effeicent then getting it with sql.

2. I have been told that I can just verify up agianst the entitymodel. Even if i use multiple entities in a view. is this true? (the one telling me this wes not able to get it to work and I have not been able to find anything about it online).

I will try to look back on this post in the next couple of hours, but might have to wait 24 hours.

Answer 1

public static List<Menu> GetTabListForMenu(string langue)
{
    Page_dbEntities entity = new Page_dbEntities();
    return (from ml in entity.wpmenulangue
            where ml.Langue == langue
            from m in entity.wpmenu
            where ml.Menu == m.Id
            from l in entity.wplangue
            where ml.Langue == l.Langue
            from p in entity.wppage
            where p.Id == m.Page
            select new Menu(m.Id, p.Controller, p.Action, p.Parameter, ml.Text)
    ).ToList();
}

As for the validation is concerned you shouldn't use multiple entities in the view. You should use a single entity which is called ViewModel. This ViewModel is a class that represents the data on the view. If you are using DataAnnotations for validation you could decorate this view model properties with attributes that indicate how to be validated.