ASP.NET Web API - ModelBinders

Question

I need to use a custom modelbinder of some kind to always treat incoming dates in UK format, i have setup a custom model binder and registered like so:

Globa         


        

Answer 1

You can register a model binder globally by implementing a ModelBinderProvider and inserting it into the list of services.

Example use in Global.asax:

GlobalConfiguration.Configuration.Services.Insert(typeof(ModelBinderProvider), 0, new Core.Api.ModelBinders.DateTimeModelBinderProvider());

Below is example code demonstrating a ModelBinderProvider and a ModelProvider implemenation that converts DateTime arguments in a culture aware manner (using the current threads culture);

DateTimeModelBinderProvider implementation:

using System;
using System.Web.Http;
using System.Web.Http.ModelBinding;

...

public class DateTimeModelBinderProvider : ModelBinderProvider
{
    readonly DateTimeModelBinder binder = new DateTimeModelBinder();

    public override IModelBinder GetBinder(HttpConfiguration configuration, Type modelType)
    {
        if (DateTimeModelBinder.CanBindType(modelType))
        {
            return binder;
        }

        return null; 
    }
}

DateTimeModelBinder implementation:

public class DateTimeModelBinder : IModelBinder
{
    public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
    {
        ValidateBindingContext(bindingContext);

        if (!bindingContext.ValueProvider.ContainsPrefix(bindingContext.ModelName) ||
            !CanBindType(bindingContext.ModelType))
        {
            return false;
        }

        bindingContext.Model = bindingContext.ValueProvider
            .GetValue(bindingContext.ModelName)
            .ConvertTo(bindingContext.ModelType, Thread.CurrentThread.CurrentCulture);

        bindingContext.ValidationNode.ValidateAllProperties = true;

        return true;
    }

    private static void ValidateBindingContext(ModelBindingContext bindingContext)
    {
        if (bindingContext == null)
        {
            throw new ArgumentNullException("bindingContext");
        }

        if (bindingContext.ModelMetadata == null)
        {
            throw new ArgumentException("ModelMetadata cannot be null", "bindingContext");
        }
    }

    public static bool CanBindType(Type modelType)
    {
        return modelType == typeof(DateTime) || modelType == typeof(DateTime?);
    }
}