MVC2 DataAnnotations on ViewModel - Don't understand using it with MVVM pattern
- by ScottSEA
I have an MVC2 Application that uses MVVM pattern. I am trying use Data Annotations to validate form input.
In my ThingsController I have two methods:
[HttpGet]
public ActionResult Index()
{
return View();
}
public ActionResult Details(ThingsViewModel tvm)
{
if (!ModelState.IsValid) return View(tvm);
try
{
Query q = new Query(tvm.Query);
ThingRepository repository = new ThingRepository(q);
tvm.Things = repository.All();
return View(tvm);
}
catch (Exception)
{
return View();
}
}
My Details.aspx view is strongly typed to the ThingsViewModel:
<%@ Page Title=""
Language="C#"
MasterPageFile="~/Views/Shared/Site.Master"
Inherits="System.Web.Mvc.ViewPage<Config.Web.Models.ThingsViewModel>" %>
The ViewModel is a class consisting of a IList of returned Thing objects and the Query string (which is submitted on the form) and has the Required data annotation:
public class ThingsViewModel
{
public IList<Thing> Things{ get; set; }
[Required(ErrorMessage="You must enter a query")]
public string Query { get; set; }
}
When I run this, and click the submit button on the form without entering a value I get a YSOD with the following error:
The model item passed into the dictionary is of type
'Config.Web.Models.ThingsViewModel', but this dictionary
requires a model item of type
System.Collections.Generic.IEnumerable`1[Config.Domain.Entities.Thing]'.
How can I get Data Annotations to work with a ViewModel? I cannot see what I'm missing or where I'm going wrong - the VM was working just fine before I started mucking around with validation.
