Pass model value from View to controller is not working - asp.net

Question

My model has two properties, one of them is an object of another class
public class Association : Entity
{
public Association()
{
this.User = new User();
}
public User User
{
get;
set;
}
public Role Role
{
get;
set;
}
};
and my view is strongly typed to this model
#model MuddyBoots.Greenlight.Association
.
.
#using (Html.BeginForm())
{
#Html.ValidationSummary(true)
<div>
#Html.TextBoxFor(model => model.User.FirstName,new { id = "first-name" })
<span class="red-asterisk">#Html.ValidationMessageFor(model => model.User.FirstName)</span>
</div>
<div>
#Html.HiddenFor(model => model.Role, new { id="hiddenRole"})
<ul id="user-roles">
<li><input type="radio" name="user-role" id="role-admin" value="01" checked="checked" /> Read only</li>
<li><input type="radio" name="user-role" id="role-member" value="02" /> Restricted</li>
<li><input type="radio" name="user-role" id="role-read" value="03"/> Standard</li>
<li><input type="radio" name="user-role" id="role-subscriber" value="04" /> Administrator</li>
</ul>
</div>
}
my controller function is written like that:
[HttpPost]
public ActionResult AddUser(Association association)
{
string firstName = association.User.FirstName;
var role = association.Role;
IRepository<Association> associationRepository = new IRepository<Association>(db);
if (ModelState.IsValid)
{
siteRepository.Update(site);
return RedirectToAction("Index");
}
return View(association);
}
My problem is: when I post my view, my association object is null, it has no values.
to be more precise, when I try to debug these 2 lines:
string firstName = association.User.FirstName;
var role = association.Role;
their values are null, but if I comment the first line, the role variable has a value. So am sensing that the problem is related to the User property, but I do not know how to solve it.

Answer 1

You seem to have used some hidden field for the Role type:
#Html.HiddenFor(model => model.Role, new { id = "hiddenRole" })
But the Role property is a complex type, you cannot serialize it as a hidden field. You will have to use hidden fields for each of the properties you want to be sent:
#Html.HiddenFor(model => model.Role.Property1)
#Html.HiddenFor(model => model.Role.Property2)
#Html.HiddenFor(model => model.Role.Property...)
Also you seem to be using some radio buttons inside your form which are named user-role but you cannot have a property on your Role class with this name (you cannot have dash in a property name), so I guess you will have to use the proper name here if you want the value of those radio buttons to be bound to some property of the Role class on your Association model.
For example let's suppose that your Role class looks like this:
public class Role
{
public string Value { get; set; }
}
Now your view could look like this:
#using (Html.BeginForm())
{
#Html.ValidationSummary(true)
<div>
#Html.TextBoxFor(model => model.User.FirstName, new { id = "first-name" })
<span class="red-asterisk">
#Html.ValidationMessageFor(model => model.User.FirstName)
</span>
</div>
<div>
<ul id="user-roles">
<li>
#Html.RadioButtonFor(model => model.Role.Value, "01", new { id = "role-admin" })
Read only
</li>
<li>
#Html.RadioButtonFor(model => model.Role.Value, "02", new { id = "role-member" })
Restricted
</li>
<li>
#Html.RadioButtonFor(model => model.Role.Value, "03", new { id = "role-read" })
Standard
</li>
<li>
#Html.RadioButtonFor(model => model.Role.Value, "04", new { id = "role-subscriber" })
Administrator
</li>
</ul>
</div>
<button type="submit">OK</button>
}

Answer 2

I don't think the ModelBinder will bind child objects. You could create a custom ModelBinder to to bind your Association class or just create a ViewModel class that flattens your current Model into a single class. So your AssociationViewModel model class might look like this:
public class AssociationViewModel
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string RoleName { get; set; }
}
public ActionResult AddUser(AssociationViewModel associationViewModel)
{
if (ModelState.IsValid)
{
var association = new Association
{
User.FirstName = associationViewModel.FirstName,
Role = new Role { Name = associationViewModel.RoleName }
};
IRepository<Association> associationRepository = new IRepository<Association>(db);
....
}
}