Issue with Web Api Custom Model Binder in MVC4 - asp.net-mvc-4

Question

I am using Mvc4 with WebApi.
I am using Dto objects for the webApi.
I am having enum as below.
public enum Status
{
[FlexinumDefault]
Unknown = -1,
Active = 0,
Inactive = 100,
}
Dto structure is as follows.
[DataContract]
public class abc()
{
[DataMemebr]
[Required]
int Id{get;set;}
[DataMember]
[Required]
Status status{get;set}
}
I have created Custom Model Binder which will validate the enum(status) property in the dto object and return false if the enum value is not passed.
if the status enum property is not passed in the dto object,we should throw exception
public bool BindModel(System.Web.Http.Controllers.HttpActionContext actionContext, System.Web.Http.ModelBinding.ModelBindingContext bindingContext)
{
var input = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
if (input != null && !string.IsNullOrEmpty(input.AttemptedValue))
{
if (bindingContext.ModelType == typeof(Enum))
{
//var actualValue = null;
var value = input.RawValue;
in the api controller,i have action method like
public void Create([FromUri(BinderType = typeof(EnumCustomModelBinder))]abcdto abc)
{
In global.asax.cs
i have set like
GlobalConfiguration.Configuration.BindParameter(typeof(Enum), new EnumCustomModelBinder());
the issue i am facing is the custombinder
var input = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
,the input value is coming as null.
Please sugggest

Answer 1

I found the solution
This works fine,but the default implementation of model binder is missing.
public bool BindModel(System.Web.Http.Controllers.HttpActionContext actionContext, ModelBindingContext bindingContext)
{
var json = actionContext.Request.Content.ReadAsStringAsync().Result;
if (!string.IsNullOrEmpty(json))
{
var jsonObject = (JObject) Newtonsoft.Json.JsonConvert.DeserializeObject(json);
var jsonPropertyNames = jsonObject.Properties().Select(p => p.Name).ToList();
var requiredProperties = bindingContext.ModelType.GetProperties().Where(p =>p.GetCustomAttributes(typeof(RequiredAttribute),
false).Any()).ToList();
var missingProperties = requiredProperties.Where(bindingProperty => !jsonPropertyNames.Contains(bindingProperty.Name)).ToList();
if (missingProperties.Count > 0)
{
missingProperties.ForEach(
prop =>
{
if (prop.PropertyType.IsEnum)
actionContext.ModelState.AddModelError(prop.Name, prop.Name + " is Required");
});
}
var nullProperties = requiredProperties.Except(missingProperties).ToList();
if (nullProperties.Count > 0)
{
nullProperties.ForEach(p =>
{
var jsonvalue = JObject.Parse(json);
var value = (JValue)jsonvalue[p.Name];
if (value.Value == null)
{
actionContext.ModelState.AddModelError(p.Name, p.Name + " is Required");
}
});
}
}
// Now we can try to eval the object's properties using reflection.
return true;
}