I'm trying to register a custom model binder in Web Api, but can't seem to find the correct way to do it.
System.ArgumentException: 'The service type SimpleModelBinderProvider is not supported.'
WebApiConfig.cs
using System.Web.Http;
using System.Web.ModelBinding;
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
...
var provider = new SimpleModelBinderProvider(typeof(CustomerIdentity), new CustomerIdentityModelBinder());
config.Services.Insert(typeof(SimpleModelBinderProvider), 0, provider);
...
}
}
I've tried SimpleModelBinderProvider and ModelBinderProvider.
What is the proper way to register a custom model binder in web api?
NOTE: I'm not using the ModelBinderAttribute on the class because it's in another assembly which would cause a circular-dependency (and because I don't like decorating classes with attributes).
NOTE: Starting to think this might be namespace related. The project has both MVC5 and WebApi2 in it.
Namespace Issue
I should have been using the namespaces:
// In the WebApiConfig.
using System.Web.Http.ModelBinding;
using System.Web.Http.ModelBinding.Binders;
// For the ModelBinder itself.
using System.Web.Http.Controllers;
using System.Web.Http.ModelBinding;
using System.Web.Http.ValueProviders;
Instead of:
using System.Web.ModelBinding;
The code was near identical as well as the class names, which is why it was hard to track down and figure out.
Related
I have a solution like this:
MVC Core 2.0 application <-> Business Class library <-> Domain class library
(ViewModel) <- P1 -> (Dto) <-P2-> (Domain entity)
I created Automapper profiles in each MVC and Business projects for mapping ViewModel<->Dto (P1) and Dto<->Domain entity (P2). P1 profile&map is in MVC project, P2 profile&map is in Business library.
I then made a xUnit test project which creates a Dto object and sends it to a Business Service, inside the unit test on init I call:
Business.App.AutoMapperConfiguration.Configure();
And this unit test works exactly as expected.
I then do the same (I even copy/pasted code from Unit test) in the MVC controller and I get an error in mapping Dto to Domain entity:
Unmapped members were found. Review the types and members below...
I configured Automapper maps in startup.cs like this:
services.AddAutoMapper();
If I understand correctly this is supposed to traverse all assemblies for classes inheriting Profile and adding them to configuration.
Example map:
public class StrankaMap : Profile
{
public override string ProfileName => nameof(StrankaMap);
public StrankaMap()
{
CreateMap<SomeDto, SomeDomainEntity>().ReverseMap()
CreateMap<AnotherDto, AnotherDomainEntity>().ReverseMap()
}
}
I don't know what is the cause of this error if my unit test works but not from MVC app - I even copied the code from unit test to MVC controller and ran that. I'm suspecting an error in configuration. Do I assume correctly that inside Startup.cs adding services.AddAutoMapper(); is enough for this to work?
Solution (edit)
Apparently I misunderstood that the service.AddAutoMapper() will traverse all assemblies and search for Profile inherited classes. There might be a better solution but I used the one below, with the help of a hint from the comment #LucianBargaoanu.
I solved it like this:
// Startup.cs
services.AddAutoMapper(
typeof(Business.App.AutoMapperConfiguration),
typeof(MvcApp.Infrastructure.Configuration.AutoMapperConfiguration));
//And the AutoMapperConfiguration class:
namespace MvcApp.Infrastructure.Configuration
{
using AutoMapper;
public class AutoMapperConfiguration
{
public static void Configure()
{
Mapper.Initialize(x =>
{
x.AddProfile<Models.Mapping.StrankaMap>();
});
}
}
}
Apparently I misunderstood that the service.AddAutoMapper() will traverse all assemblies and search for Profile inherited classes. There might be a better solution but I used the one below, with the help of a hint from the comment #LucianBargaoanu.
I solved it like this:
// Startup.cs
services.AddAutoMapper(
typeof(Business.App.AutoMapperConfiguration),
typeof(MvcApp.Infrastructure.Configuration.AutoMapperConfiguration));
//And the AutoMapperConfiguration class:
namespace MvcApp.Infrastructure.Configuration
{
using AutoMapper;
public class AutoMapperConfiguration
{
public static void Configure()
{
Mapper.Initialize(x =>
{
x.AddProfile<Models.Mapping.StrankaMap>();
});
}
}
}
Entity Framework 4, Ninject 3, MVC3
Currently in my web app i have been using a rather rudimentary approach to per request instantiation of an Object Context. So I am experimenting with Ninject, and some old sample code, but I am unsure how to proceed with the following..
Effectively I want to be able in the controller to do the equivalent of: DB_Entities.Current.Albums ... Should i be instantiating a StandardKernel every time?
The sample i was looking at was using the following: MvcApplication.Container.Get(); but in Ninject 3 with the App_Start hookup I dont have access to Container..
My attempt to replicate the above line, is failing at runtime.
using MusicStoreEntities;
using Ninject;
using TestMVC3WithIOC.App_Start;
using System.Data.Objects;
namespace TestMVC3WithIOC.Models
{
public partial class MusicStoreEntities
{
public static MusicStoreEntities Current
{
get
{
using (IKernel kernel = new StandardKernel())
{
return (MusicStoreEntities)kernel.Get<ObjectContext>();
}
}
}
}
}
Also, note, that in App_Start\NinjectWebCommon.cs I have the following modification:
private static void RegisterServices(IKernel kernel)
{
kernel.Bind<ILogger>().To<NLogger>();
kernel.Bind<ObjectContext>().To<MusicStoreEntities>().InRequestScope();
}
Although a workable solution, it seems ill-advised to pass the entire Kernel into a class, because it tends to obscure the classes actual, specific dependencies. A better approach is to pass a factory dependency into your controller's constructor.
public partial class MusicStoreEntities
{
private readonly IEntitiesFactory _factory;
public MusicStoreEntities(IEntitiesFactory factory)
{
_factory = factory;
}
}
IEntitiesFactory has a simple implementation with a single method GetObjectContext().
(I believe also the "Unit of Work" pattern is popular at the moment, but I can't really speak to that as I haven't used it. Maybe worth looking into.)
I use this tutorial to create Plugin Architecture in my solution and I also use ninject for the first time:
http://www.codeproject.com/script/Articles/ArticleVersion.aspx?aid=358360&av=526320&msg=4308834#xx4308834xx
Now in MVC application while user is in the process of checkout I get the payment method he selects and need to retrieve the plugin for the selected payment method. I have succeeded in retrieving plugin controller this way, though I have no idea whether it is safe or acceptable practice:
Type type = Type.GetType(paymentMethod.PaymentMethodPluginType);
//get plugin controller
var paymentController = ServiceLocator.Current.GetInstance(type) as BasePaymentController;
//get validations from plugin
var warnings = paymentController.ValidatePaymentForm(form);
//get payment info from plugin
var paymentInfo = paymentController.GetPaymentInfo(form);
//…
I also need to access a plugin class for processing the payment.
I have an interface IPaymentMethod
public partial interface IPaymentMethod
{
void PostProcessPayment (PostProcessPaymentRequest postprocessPaymentRequest);
}
And plugin PaymentProcessor like this
public class PluginPaymentProcessor :IPaymentMethod
{
public void PostProcessPayment (PostProcessPaymentRequest postprocessPaymentRequest)
{
///
}
Now in MVC project I try to access PostProcessPayment method this way
IPaymentMethod pluginpaymentmethod = ServiceLocator.Current.GetInstance<IPaymentMethod>(paymentMethod.PaymentProcessor);
here paymentMethod.PaymentProcessor is “MyApp.Plugins.MyPlugin.PluginPaymentProcessor, MyApp.Plugins.MyPlugin,Version=1.0.0.0,Culture=neutral,PublicKeyToken=null”
And want to use pluginpaymentmethod like i do in controller example
pluginpaymentmethod.PostProcessPayment(postProcessPaymentRequest);
but it throws error that resource is not found and pluginpaymentmethod is not loaded. How can I fix it or can you suggest any tutorial with similar implementations? Thank you.
assuming you have a concrete class called MyPlugin which has the IPaymentMethod interface, then your ninject bindings should look a bit like:
private static void RegisterServices(IKernel kernel){
kernel.Bind<IPaymentMethod>().To<MyPlugin>().InRequestScope();
}
check that this is in place in your NinjectWebCommon.cs class under the App_Start folder. A trickier scenario might be that IPaymentMethod has to be registered in the same way that the Ninject IKernel is bound:
kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
that would potentially be a trickier issue to work out.
I'm trying to inject a second repository into my asp.net mvc 3 controller. And I cant get it to work, not sure where to "add another" using Ninject.
I have a void function in global.asa.cs
kernel.Bind<INewsRepository>().To<NewsRepository>();
And in my controller I have:
private INewsRepository _newsRepository;
private IContentRepository _contentRepository;
public NewsController(INewsRepository newsRepository, IContentRepository contentRepository)
{
this._newsRepository = newsRepository;
this._contentRepository = contentRepository;
}
How can I register IContentRepository for the NewsController as well?
I use autofac instead of Ninject but the basics stay the same.
If you got your first dependency injection working then you should be able to bind others as well. You just have to add a new binding in Application_Start() in your Global.asax.
So under your first binding do this as well:
kernel.Bind<IContentRepository>().To<ContentRepository>();
You can have as many bindings as you like.
First off it's a good practice to move the bootstrapping of your application into a separate location. This keeps your Global.asax clean.
You should also be using convention based registration. It will end up saving you lots of time for the bindings you don't need to customize.
So for you I'd probably suggest the following
public static class Bootstrapper()
{
public static void Bootstrap()
{
kernel.Scan( k =>
{
k.FromAssemblyContaining<INewsRepository>();
k.BindWithDefaultConventions();
});
}
}
And in your Global.asax you add this..
Bootstrapper.Bootstrap();
Then I would suggest you spend some time on Google reading about ninject conventions.
What's a good way to validate a model when information external to the model is required in order for the validation to take place? For example, consider the following model:
public class Rating {
public string Comment { get; set; }
public int RatingLevel { get; set; }
}
The system administrator can then set the RatingLevels for which a comment is required. These settings are available through a settings service.
So, in order to fully validate the model I need information external to it, in this case the settings service.
I've considered the following so far:
Inject the service into the model. The DefaultModelBinder uses System.Activator to create the object so it doesn't go through the normal dependency resolver and I can't inject the service into the model without creating a new model binder (besides which, that doesn't feel like the correct way to go about it).
Inject the service into an annotation. I'm not yet sure this is possible but will investigate further soon. It still feels clumsy.
Use a custom model binder. Apparently I can implement OnPropertyValidating to do custom property validation. This seems the most preferable so far though I'm not yet sure how to do it.
Which method, above or not, is best suited to this type of validation problem?
Option 1 doesn't fit. The only way it would work would be to pull in the dependency via the service locator anti-pattern.
Option 2 doesn't work. Although I couldn't see how this was possible because of the C# attribute requirements, it is possible. See the following for references:
Resolving IoC Container Services for Validation Attributes in ASP.NET MVC
NInjectDataAnnotationsModelValidatorProvider
Option 3: I didn't know about this earlier, but what appears to be a very powerful way to write validators is to use the ModelValidator class and a corresponding ModelValidatorProvider.
First, you create your custom ModelValidatorProvider:
public class CustomModelValidatorProvider : ModelValidatorProvider
{
public CustomModelValidatorProvider(/* Your dependencies */) {}
public override IEnumerable<ModelValidator> GetValidators(ModelMetadata metadata, ControllerContext context)
{
if (metadata.ModelType == typeof(YourModel))
{
yield return new YourModelValidator(...);
}
}
}
ASP.NET MVC's IDependencyResolver will attempt to resolve the above provider, so as long as it's registered with your IoC container you won't need to do anything else. And then the ModelValidator:
public class EntryRatingViewModelValidatorMvcAdapter : ModelValidator
{
public EntryRatingViewModelValidatorMvcAdapter(
ModelMetadata argMetadata,
ControllerContext argContext)
: base(argMetadata, argContext)
{
_validator = validator;
}
public override IEnumerable<ModelValidationResult> Validate(object container)
{
if (/* error condition */)
{
yield return new ModelValidationResult
{
MemberName = "Model.Member",
Message = "Rating is required."
};
}
}
}
As the provider is retrieved through the IDependencyResolver and the provider has full control over the returned ModelValidators I was easily able to inject the dependencies and perform necessary validation.
You could try fluent validation. It supports asp.net mvc and DI so you can inject external services into your validators.
Assuming that you want both client and server-side validation of the model based upon the values returned from the service, I would opt for 2., Inject the service into an annotation.
I give some sample code in my response to this question about adding validators to a model. The only additional step in your case is that you will need to inject your service into your class inheriting from DataAnnotationsModelValidatorProvider.
What about just simply using IValidateableObject and in that method determine if validation is appropriate or not and setting the errors there?
How do I use IValidatableObject?