I am trying to inject dependency to my session dictionary class into my controller's constructor. eg:
public AccountController(ISessionDictionary sessionDictionary)
{
this.sessionDictionary = sessionDictionary;
}
In my global.asax file:
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
ModelBinders.Binders.Add(typeof(ISessionDictionary), new SessionDictionaryBinder());
}
My SessionDictionaryBinder:
public class SessionDictionaryBinder : IModelBinder
{
private const string sessionKey = "_seshDic";
public object BindModel(ControllerContext controllerContext,
ModelBindingContext bindingContext)
{
if (bindingContext.Model != null)
{
throw new InvalidOperationException("Cannot update instances");
}
ISessionDictionary seshDic = (SessionDictionary)controllerContext.HttpContext.Session[sessionKey];
if (seshDic == null)
{
seshDic = new SessionDictionary();
controllerContext.HttpContext.Session[sessionKey] = seshDic;
}
return seshDic;
}
}
When I go to /account/login, I get the error:
Error activating ISessionDictionary
No matching bindings are available, and the type is not self-bindable.
Activation path:
2) Injection of dependency ISessionDictionary into parameter sessionDictionary of constructor of type AccountController
1) Request for AccountController
I am using Ninject for DI, and my other bindings in the file contained within the App_Start directory work fine. I am assuming the modelbinder should go into that file, but what is the syntax?
Cheers!
As I see it you are mixing things up a little bit.
Here you register your model binder to the MVC3 Framework:
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
ModelBinders.Binders.Add(typeof(ISessionDictionary), new SessionDictionaryBinder());
}
Afther this registration you can write Controller actions expecting an ISessionDictionary instance, but that has nothing to do with controller constructors. Ninject doesn't know about your binding, so you have to include your binding in the Ninject module you are using (and if you don't have actions expecting an ISessionDictionary parameter, than you don't need the model binder at all)
Related
I have a well known issue where my Web API complains that my controller does not have a parameterless constructor. I have been through many pages and questions on this but cant seem to find the issue.
I installed Unity using Nuget command Install-Package Unity.WebAPI. The UnityConfig was created properly.
This is my UnityConfig file:
public static class UnityConfig
{
public static void RegisterComponents()
{
var container = new UnityContainer();
container.RegisterType<IImportHeadService, ImportHeadService>();
container.RegisterType<IImportDetailService, ImportDetailService>();
container.RegisterType<ICurrencyService, CurrencyService>();
container.RegisterType<ISupplierService, SupplierService>();
container.RegisterType<IKPIService, KPIService>();
GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
}
}
I then registered the UnityConfig in my Global.asax file as below:
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
UnityConfig.RegisterComponents();
GlobalConfiguration.Configure(WebApiConfig.Register);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
}
}
And finally, here is my ImportController which is what I am trying to call through fiddler:
public class ImportController : ApiController
{
private IImportHeadService _importHeadService;
private IImportDetailService _importDetailService;
public ImportController(IImportHeadService importHeadService, IImportDetailService importDetailService)
{
_importHeadService = importHeadService;
_importDetailService = importDetailService;
}
[HttpGet, Route("api/Import/Info")]
public HttpResponseMessage GetInfo()
{
return Request.CreateResponse(HttpStatusCode.OK, "Import Tracker v1.0 - Import Controller");
}
}
As you can see it is a very simple controller at this point but I receive the following error:
An error occurred when trying to create a controller of type 'ImportController'. Make sure that the controller has a parameterless public constructor.
OK, so I was being a bit silly after all. My services have a parameter in their constructor for a context. Once I added the context into the Unity configuration. It all worked.
I am trying to set up structure map ver 3.0.5.0 with Web API 2.
I have followed this implementation: Configuring dependency injection with ASP.NET Web API 2.1
However, I am getting this error when doing a get against my ComplexesController:
An error occurred when trying to create a controller of type 'ComplexesController'. Make sure that the controller has a parameterless public constructor.
Can anyone see what is wrong with my structuremap config? The Create method never gets called.
This is my implementation:
public class StructureMapControllerActivator : IHttpControllerActivator
{
private readonly IContainer _container;
public StructureMapControllerActivator(IContainer container)
{
if (container == null) throw new ArgumentNullException("container");
_container = container;
}
public IHttpController Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)
{
try
{
var scopedContainer = _container.GetNestedContainer();
scopedContainer.Inject(typeof(HttpRequestMessage), request);
request.RegisterForDispose(scopedContainer);
return (IHttpController)scopedContainer.GetInstance(controllerType);
}
catch (Exception e)
{
// TODO : Logging
throw e;
}
}
}
This method is in my startup...
public void InitializeContainer()
{
// STRUCTURE MAP
Container container = new Container();
GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerActivator), new StructureMapControllerActivator(container));
container.Configure(x => x.For<IForumRepository>().Use<ForumRepository>());
container.Configure(x => x.For<IComplexRepository>().Use<ComplexRepository>());
}
.. and this is the controller:
public class ComplexesController : ApiController
{
private IComplexRepository _repo;
public ComplexesController(IComplexRepository repo)
{
_repo = repo;
}
// GET: api/Complexes
public IList<Complex> GetComplexes()
{
var complexes = _repo.GetList();
return complexes;
}
...
My full Startup class
[assembly: OwinStartup(typeof(AngularJSAuthentication.API.Startup))]
namespace AngularJSAuthentication.API
{
public class Startup
{
public void Configuration(IAppBuilder app)
{
HttpConfiguration config = new HttpConfiguration();
WebApiConfig.Register(config);
app.UseWebApi(config);
}
}
}
The problem here is that you are registering your service activator with a GlobalConfiguration object and not your HttpConfiguration object. In this scenario The GlobalConfiguration object is never used as it is replaced by the HttpConfiguration object. In order to solve your issue you should replace your InitializeContainer() method with the following.
public void InitializeContainer(HttpConfiguration config)
{
// STRUCTURE MAP
Container container = new Container();
config.Services.Replace(typeof(IHttpControllerActivator), new StructureMapControllerActivator(container));
container.Configure(x => x.For<IForumRepository>().Use<ForumRepository>());
container.Configure(x => x.For<IComplexRepository>().Use<ComplexRepository>());
}
you should then pass the HttpConfiguration object from your Startup class to the new InitializeContainer() method.
Hope this helps.
-B
I am trying to gain a solid understanding of the complete lifecycle. I think my setup may be slightly different to the above. Here is what worked for me.
public partial class Startup
{
public void Configuration(IAppBuilder app)
{
var config = new HttpConfiguration();
var container = IocConfig.Setup();
// Allow a controller to be declared without a parameterless constructor
config.DependencyResolver = new DependencyResolver(container);
config.Services.Add( typeof(IExceptionLogger), new GlobalExceptionLogger( container.GetInstance<ILoggingService>()));
// Web API routes
config.MapHttpAttributeRoutes();
// Setup Authentication
ConfigureOAuth(app, container);
var corsOptions = CorsOptions.AllowAll;
app.UseCors(corsOptions);
// Add ASP.Net Web API to OWIN pipeline
app.UseWebApi(config);
}
}
It worked after I added this line:
// Allow a controller to be declared without a parameterless constructor
config.DependencyResolver = new DependencyResolver(container);
You have to get that my var container loads from a static class called IocConfig with a static Setup method. This is where the interfaces are mapped to their concrete implementations.
Also, you can probably ignore the GlobalExceptionLogger line if you want to use my complete example.
I've got a class that requires access to the HttpRequestMessage in my Web API service. At the moment, I've got the following code to capture the message in the pipeline and save it for later (based on this and this):
public class ContextCapturingControllerActivator : IHttpControllerActivator
{
private readonly IKernel kernel;
private HttpRequestMessage requestMessage;
public ContextCapturingControllerActivator(IKernel kernel)
{
this.kernel = kernel;
}
public IHttpController Create(HttpRequestMessage requestMessage,
HttpControllerDescriptor controllerDescriptor,
Type controllerType)
{
this.kernel.Rebind<HttpRequestMessage>()
.ToConstant<HttpRequestMessage>(requestMessage);
var controller = (IHttpController)this.kernel.GetService(controllerType);
this.requestMessage = requestMessage;
requestMessage.RegisterForDispose(
new Release(() => this.kernel.Release(controller)));
return controller;
}
private class Release : IDisposable
{
private readonly Action release;
public Release(Action release)
{
this.release = release;
}
public void Dispose()
{
this.release();
}
}
}
In my composition root, I configure the ControllerActivator:
kernel.Bind<IHttpControllerActivator>()
.To<ContextCapturingControllerActivator>();
The end result is that from the perspective of the configuration, the HttpRequestMessage is "magically" injected wherever it is requested since it is done for us inside the ControllerActivator. I have not been able to inject the message from my composition root. I'm also not crazy about the Rebind since it's there to avoid adding a new binding every time the service is called. I suspect it's due to the singleton nature of the Web API stack, but have not been able to sort out how to deal with that properly.
In general, I cannot use the latest unstable Nuget package of Ninject web api due to the error reported (and ignored) here.
Can anyone suggest the proper way to improve my code to make it a bit more clear and make life easier for future maintainers (and let's face it -- that's probably going to be me).
Thanks.
Here is what I did, but I believe it depends on Web API 2.0+.
I created an instance class that wraps the current context's http request:
public class HttpRequestMessageWrapper
{
private readonly HttpRequestMessage m_httpRequestMessage;
public HttpRequestMessageWrapper()
{
m_httpRequestMessage = HttpContext.Current.Items["MS_HttpRequestMessage"] as HttpRequestMessage;
}
public HttpRequestMessage RequestMessage
{
get
{
return m_httpRequestMessage;
}
}
}
Then I bound the HttpRequestMessage to the property with the ToMethod binding in request scope.
container.Bind<HttpRequestMessage>().ToMethod(ctx => new HttpRequestMessageWrapper().RequestMessage).InRequestScope();
I've tried the method that #Mackers proposed which is the cleanest way.... however, in my specific scenario, it didn't work due to a timing issue. For my case, I needed to inject an object into the apicontroller ctor and that object required the HttpRequestMessage. The HttpContext.Current.Items["MS_HttpRequestMessage"]isn't populated until the controller has been constructed and initialized and I couldn't find any other way to access it. So I resorted to creating a custom DelegatingHandler and rebinding the current request message as they come in.
public class CurrentHttpRequestMessageHandler : DelegatingHandler
{
[SecuritySafeCritical]
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
UpdateScopeWithHttpRequestMessage(request);
return base.SendAsync(request, cancellationToken);
}
internal static void UpdateScopeWithHttpRequestMessage(HttpRequestMessage request)
{
NinjectConfig.GetConfiguredKernel().Rebind<HttpRequestMessage>().ToMethod(ctx => { return request; })
.InRequestScope();
}
}
The GetConfiguredKernel is a static method I created to simply return the static Kernel instance already configured.
public class NinjectConfig
{
private static readonly Bootstrapper bootstrapper = new Bootstrapper();
private static StandardKernel _kernel;
public static void Start()
{
DynamicModuleUtility.RegisterModule(typeof(OnePerRequestHttpModule));
DynamicModuleUtility.RegisterModule(typeof(NinjectHttpModule));
bootstrapper.Initialize(CreateKernel);
}
public static IKernel GetConfiguredKernel()
{
if (_kernel != null)
return _kernel;
return CreateKernel();
}
....
Then register the DelegatingHandler with the HttpConfiguration:
config.MessageHandlers.Add(new CurrentHttpRequestMessageHandler());
Building off of Macker's answer, System.Web has an HttpRequestBase class that you can use and simplify unit testing the code. Anywhere in the code that the request is required, specify the HttpRequestBase type as the constructor parameter and register it with the below method:
Ninject example:
Bind<HttpRequestBase>().ToMethod(context => new HttpRequestWrapper(HttpContext.Current.Request));
Unity example:
container.RegisterType<HttpRequestBase>(new InjectionFactory(_ => new HttpRequestWrapper(HttpContext.Current.Request)));
I'm trying to build an implementation of the IHttpControllerActivator interface for with with StructureMap, so that I can resolve a dependency of a controller which takes a dependency on the HttpRequestMessage being processed in the MVC Web API pipeline.
My implementation of Create is as follows:
public IHttpController Create(
HttpRequestMessage request,
HttpControllerDescriptor controllerDescriptor,
Type controllerType)
{
return (IHttpController)this.Container
.With(request)
.With(controllerDescriptor)
.GetInstance(controllerType);
}
The Container property is a reference to the StructureMap IContainer instance passed to the activator when it is constructed.
My registration for the controllers uses reflection to obtain all the ApiController implementations:
foreach(var controller in this.GetType().Assembly.GetTypes()
.Where(type => typeof(ApiController).IsAssignableFrom(type)))
{
this.For(controller).Use(controller);
}
Using the debugger, I checked that initialises the controller instances and passes in their dependencies. However, when the ExecuteAsync method is called on the controller, an exception is thrown:
Cannot reuse an 'ApiController' instance. 'ApiController' has to be constructed per incoming message. Check your custom 'IHttpControllerActivator' and make sure that it will not manufacture the same instance.
After some digging and experimentation I discovered this is due to a check performed at the start of ExecuteAsync which checks the Request property of the ApiController to see if it has been assigned a value. If the property has a non-null value, it infers that the controller has already been used to process a request and aborts the operation.
Further to this, I verified that StructureMap attempted to use its setter-injection behaviour when composing the controller and is responsible for Request having a non-null value.
In my registry, I haven't configured any setter-injection, so I'm confused as to why it's being invoked here. A poke around the StructureMap API hasn't yielded any obvious answers as to how I could change the behaviour exhibited.
Am I invoking StructureMap incorrectly? Is there a configuration setting I can leverage to say "never ever assign a property value"?
I think your issue revolves around the way that you are setting up your controllers with StructureMap. In order to get this working correctly, the best way is to hook into the WebAPI stack's dependency injection stack by creating your own implementation of IDependencyResolver. There's a pretty good example of this at http://craigsdevspace.wordpress.com/2012/02/26/using-structuremap-with-web-api/
The basic code, though, might look something like:
IDependencyResolver:
public class _DependencyResolver : _DependencyScope, IDependencyResolver {
public _DependencyResolver(IContainer container) : base(container) { }
public IDependencyScope BeginScope() {
return new _DependencyScope(_container);
}
}
IDependencyScope:
public class _DependencyScope : ServiceLocatorImplBase, IDependencyScope {
protected readonly IContainer _container;
public _DependencyScope(IContainer container) {
if (container == null)
throw new ArgumentNullException("container");
_container = container;
}
public override object GetService(Type serviceType) {
if (serviceType == null)
return null;
try {
return (serviceType.IsAbstract || serviceType.IsInterface)
? _container.TryGetInstance(serviceType)
: _container.GetInstance(serviceType);
} catch {
return null;
}
}
protected override object DoGetInstance(Type serviceType, string key) {
if (string.IsNullOrEmpty(key))
return _container.TryGetInstance(serviceType);
return _container.TryGetInstance(serviceType, key);
}
protected override IEnumerable<object> DoGetAllInstances(Type serviceType) {
return _container.GetAllInstances<object>().Where(s => s.GetType() == serviceType);
}
public IEnumerable<object> GetServices(Type serviceType) {
return _container.GetAllInstances<object>().Where(s => s.GetType() == serviceType);
}
public void Dispose() {
//_container.Dispose();
}
}
To hook these classes up to WebAPI, then, you would add the following to Global.asax:
GlobalConfiguration.Configuration.DependencyResolver =
new _DependencyResolver(ObjectFactory.Container);
And either in Global.asax or in your Bootstrapper, you would add the following:
ObjectFactory.Initialize(x => {
x.Scan(scanner => scanner.AddAllTypesOf<ApiController>());
});
This sets up your StructureMap implementation to use the stack's pre-existing injection structure - which should avoid the problem that you're having.
I've created a custom DataAnnotationsModelValidatorProvider:
public class CustomValidatorProvider : DataAnnotationsModelValidatorProvider
{
protected override IEnumerable<ModelValidator> GetValidators(ModelMetadata metadata, ControllerContext context, IEnumerable<Attribute> attributes)
{
//Do custom stuff...
return base.GetValidators(metadata, context, attributes);
}
}
And I've registered it in my Global.asax:
ModelValidatorProviders.Providers.Add(new CustomValidatorProvider());
I put a breakpoint in the GetValidators method but it is never hit. My understanding is that this custom validator provider should be executed for each property in my model. Am I missing something?
I think you need to override from ModelValidatorProvider and not DataAnnotationsModelValidatorProvider. And the method signature should not have the attributes parameter and should be public:
public class CustomValidatorProvider : ModelValidatorProvider
{
public override IEnumerable<ModelValidator> GetValidators(ModelMetadata metadata, ControllerContext context)
{
//Do custom stuff...
//You cannot call the base here as ModelValidatorProvider is abstract.
//return base.GetValidators(metadata, context);
}
}
ModelValidatorProviders.Providers already contain a DataAnnotationsModelValidatorProvider.
Simply remove it before adding your custom DataAnnotationsModelValidatorProvider.
ModelValidatorProviders.Providers.Remove(ModelValidatorProviders.Providers.OfType<DataAnnotationsModelValidatorProvider>().First());
ModelValidatorProviders.Providers.Add(new DependencyResolverModelValidatorProvider());