I need to create a dynamic input form based on a derived type but I cannot get complex properties bound properly when passed to the POST method of my controller. Other properties bind fine. Here is a contrived example of what I have:
Model
public abstract class ModelBase {}
public class ModelDerivedA : ModelBase
{
public string SomeProperty { get; set; }
public SomeType MySomeType{ get; set; }
public ModelDerivedA()
{
MySomeType = new SomeType();
}
}
public class SomeType
{
public string SomeTypeStringA { get; set; }
public string SomeTypeStringB { get; set; }
}
Custom Model Binder
The binder is based on this answer: polymorphic-model-binding
public class BaseViewModelBinder : DefaultModelBinder
{
protected override object CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType)
{
var typeValue = bindingContext.ValueProvider.GetValue("ModelType");
var type = Type.GetType(
(string)typeValue.ConvertTo(typeof(string)),
true
);
if (!typeof(ModelBase).IsAssignableFrom(type))
{
throw new InvalidOperationException("The model does not inherit from mode base");
}
var model = Activator.CreateInstance(type);
bindingContext.ModelMetadata = ModelMetadataProviders.Current.GetMetadataForType(() => model, type);
return model;
}
}
Controller
[HttpPost]
public ActionResult GetDynamicForm([ModelBinder(typeof(BaseViewModelBinder))] ModelBase model)
{
// model HAS values for SomeProperty
// model has NO values for MySomeType
}
View Excerpt
@Html.Hidden("ModelType", Model.GetType())
@Html.Test(Model);
JavaScript
The form is posted using $.ajax
using data: $(this).serialize()
, which, if I debug shows the correct populated form data.
All properties are populated in the model excluding those of SomeType
. What do I need to change to get them populated?
Thanks