Question

What I have is a model which has one of it’s attributes dynamic. This dynamic attribute holds one of about 50 different objects. This model is send to a view that dynamic creates the page based on which object is used. This is working perfectly … the issue is the postback. When the model posts back the modelbinder is not able to bind the dynamic attribute. I was expecting this and thought I would be able to handle it but nothing that I tried works appart from making an action for EACH different objects.

Model

public class VM_List
{
    public Config.CIType CIType { get; set; }
    public dynamic SearchData { get; set; }
   //Lots of static fields
}

This works

public ActionResult List_Person(VM_List Model, VM_Person_List SearchData)
{
Model.SearchData = SearchData;
//Stuff
}

public ActionResult List_Car(VM_List Model, VM_Car_List SearchData)
{
Model.SearchData = SearchData;
//Stuff
}

But what I want is a single action

public ActionResult List(VM_List Model)
{
    //Stuff
}

I have tried things like

public ActionResult List(VM_List Model)
{

        switch (Model.CIType)
        {
            case Config.CIType.Person:
                UpdateModel((VM_Person_List)Model.SearchData);
                break;
            default:
                SearchData = null;
                break;
        }

    //Stuff
}

and a Custom modelbinder

CIType CIType = (CIType)bindingContext.ValueProvider.GetValue("CIType").ConvertTo(typeof(CIType));

switch (CIType)
{
            case Config.CIType.Person:
                SearchData = (VM_Person_List)bindingContext.ValueProvider.GetValue("SearchData").ConvertTo(typeof(VM_Person_List));
                break;
            default:
                SearchData = null;
                break;
        }

but I can’t get either to work. Any ideas?

Answer 1

After trying many different things I finally found a way that works.

Action:

public ActionResult List(VM_List Model)
{

//If the defaultmodelbinder fails SearchData will be an object
if(Model.SearchData.GetType() == typeof(object))
{

//Get SearchData as a Dictionary
Dictionary<string, string> DSearchData = Request.QueryString.AllKeys.Where(k => k.StartsWith("SearchData.")).ToDictionary(k => k.Substring(11), k => Request.QueryString[k]);

switch (Model.CIType)
{
                case Config.CIType.Person:
                    Model.SearchData = new VM_Person_List(DSearchData);
                    break;
                case Config.CIType.Car:
                    Model.SearchData = new VM_Car_List(DSearchData);
                    break;
}

//Rest of action
//..
        }

and for each object make a constructor that accepts a dictionary

public VM_Car_List(Dictionary<string, string> DSearchData)
{
    this.Make = Convert.ToInt32(DSearchData["Make"]);
    this.Model = Convert.ToInt32(DSearchData["Model"]);
    this.Year = Convert.ToInt32(DSearchData["Year"]);
    // ETC
}