Asp.net-mvc – ASP.NET MVC – Mixing Custom and Default Model Binding

asp.net-mvcmodelbinders

I have a type:

public class IssueForm
{
    Order Order {get; set;}
    Item Item {get; set;}
    Range Range {get; set;}
}

I created a custom model binder due to requirements on Order and Item, but Range could still use the Default Model Binder.

Is there a way from within my custom model binder to call the default model binder to return a Range object? I think I just have to just setup ModelBindingContext correctly, but I don't know how.

EDIT

Looking at the first comment and answer — it seems like inheriting from the default model binder could be useful.

To add more specifics for my setup so far I have:

public IssueFormModelBinder : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        Order = //code to pull the OrderNumber from the context and create an Order
        Item = //code to pull the ItemNumber from the context and create an Item

        IssueForm form = IssueFormFactory.Create(Order, Item);

        form.Range = // ** I'd like to replace my code with a call to the default binder **

        return form
    }
}

This might be a stupid way of doing it… this is my first model binder. Just pointing out my current implementation.

EDIT #2

So the answers to override BindProperty will work if I can hook into like a "I'm all done binding" method and call the Factory method with the properties.

I guess I really should look at the DefaultModelBinder implementation and quit being stupid.

Best Answer

override the BindProperty from the DefaultModelBinder:

public class CustomModelBinder:DefaultModelBinder
        {
            protected override void BindProperty( ControllerContext controllerContext, ModelBindingContext bindingContext, System.ComponentModel.PropertyDescriptor propertyDescriptor )
            {
                if (propertyDescriptor.PropertyType == typeof(Range))
                {
                    base.BindProperty(controllerContext, bindingContext, propertyDescriptor);
                }
                // bind the other properties here
            }
        }

Related Solutions

Asp.net-mvc – ASP.NET MVC – Set custom IIdentity or IPrincipal

Here's how I do it.

I decided to use IPrincipal instead of IIdentity because it means I don't have to implement both IIdentity and IPrincipal.

Create the interface

interface ICustomPrincipal : IPrincipal
{
    int Id { get; set; }
    string FirstName { get; set; }
    string LastName { get; set; }
}

CustomPrincipal

public class CustomPrincipal : ICustomPrincipal
{
    public IIdentity Identity { get; private set; }
    public bool IsInRole(string role) { return false; }

    public CustomPrincipal(string email)
    {
        this.Identity = new GenericIdentity(email);
    }

    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

CustomPrincipalSerializeModel - for serializing custom information into userdata field in FormsAuthenticationTicket object.

public class CustomPrincipalSerializeModel
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

if (Membership.ValidateUser(viewModel.Email, viewModel.Password))
{
    var user = userRepository.Users.Where(u => u.Email == viewModel.Email).First();

    CustomPrincipalSerializeModel serializeModel = new CustomPrincipalSerializeModel();
    serializeModel.Id = user.Id;
    serializeModel.FirstName = user.FirstName;
    serializeModel.LastName = user.LastName;

    JavaScriptSerializer serializer = new JavaScriptSerializer();

    string userData = serializer.Serialize(serializeModel);

    FormsAuthenticationTicket authTicket = new FormsAuthenticationTicket(
             1,
             viewModel.Email,
             DateTime.Now,
             DateTime.Now.AddMinutes(15),
             false,
             userData);

    string encTicket = FormsAuthentication.Encrypt(authTicket);
    HttpCookie faCookie = new HttpCookie(FormsAuthentication.FormsCookieName, encTicket);
    Response.Cookies.Add(faCookie);

    return RedirectToAction("Index", "Home");
}

Global.asax.cs - Reading cookie and replacing HttpContext.User object, this is done by overriding PostAuthenticateRequest

protected void Application_PostAuthenticateRequest(Object sender, EventArgs e)
{
    HttpCookie authCookie = Request.Cookies[FormsAuthentication.FormsCookieName];

    if (authCookie != null)
    {
        FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);

        JavaScriptSerializer serializer = new JavaScriptSerializer();

        CustomPrincipalSerializeModel serializeModel = serializer.Deserialize<CustomPrincipalSerializeModel>(authTicket.UserData);

        CustomPrincipal newUser = new CustomPrincipal(authTicket.Name);
        newUser.Id = serializeModel.Id;
        newUser.FirstName = serializeModel.FirstName;
        newUser.LastName = serializeModel.LastName;

        HttpContext.Current.User = newUser;
    }
}

Access in Razor views

@((User as CustomPrincipal).Id)
@((User as CustomPrincipal).FirstName)
@((User as CustomPrincipal).LastName)

and in code:

    (User as CustomPrincipal).Id
    (User as CustomPrincipal).FirstName
    (User as CustomPrincipal).LastName

I think the code is self-explanatory. If it isn't, let me know.

Additionally to make the access even easier you can create a base controller and override the returned User object (HttpContext.User):

public class BaseController : Controller
{
    protected virtual new CustomPrincipal User
    {
        get { return HttpContext.User as CustomPrincipal; }
    }
}

and then, for each controller:

public class AccountController : BaseController
{
    // ...
}

which will allow you to access custom fields in code like this:

User.Id
User.FirstName
User.LastName

But this will not work inside views. For that you would need to create a custom WebViewPage implementation:

public abstract class BaseViewPage : WebViewPage
{
    public virtual new CustomPrincipal User
    {
        get { return base.User as CustomPrincipal; }
    }
}

public abstract class BaseViewPage<TModel> : WebViewPage<TModel>
{
    public virtual new CustomPrincipal User
    {
        get { return base.User as CustomPrincipal; }
    }
}

Make it a default page type in Views/web.config:

<pages pageBaseType="Your.Namespace.BaseViewPage">
  <namespaces>
    <add namespace="System.Web.Mvc" />
    <add namespace="System.Web.Mvc.Ajax" />
    <add namespace="System.Web.Mvc.Html" />
    <add namespace="System.Web.Routing" />
  </namespaces>
</pages>

and in views, you can access it like this:

@User.FirstName
@User.LastName

R – S#arp Architecture model binder enumeration error

There appears to be a bug in the sharp architecture SetEntityCollectionProperty method. Its in the last four lines:

        foreach (object entity in (value as IEnumerable)) {
            entityCollectionType.InvokeMember("Add",
                BindingFlags.Public | BindingFlags.Instance | BindingFlags.InvokeMethod, null, entityCollection,
                new object[] { entity });
        }

Its intent seems to be to populate the model collection class (entityCollection) from the values in the IEnumerable passed in as value. However, these two objects are the same reference. It's already populated. When the "Add" method is invoked, the entityCollection is modified which is the same object that is being iterated. Then the exception is thrown.

Comment or delete that code block and your code should run.

Best Answer

Related Solutions

Asp.net-mvc – ASP.NET MVC – Set custom IIdentity or IPrincipal

R – S#arp Architecture model binder enumeration error

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