CODEWITHSUNDEEP
c#asp.net-web-apidependency-injectionunity-container
Matthew Flynn
Matthew Flynn

Reputation: 3941

Unity DI in AuthorisationFilter WebApi

I have used this link here as a reference;

https://unity.codeplex.com/discussions/446780

So as per the link I have added a UnityActionFilterProvider class;

public class UnityActionFilterProvider : ActionDescriptorFilterProvider, IFilterProvider
{
    private readonly IUnityContainer container;

    public UnityActionFilterProvider(IUnityContainer container)
    {
        this.container = container;
    }

    public new IEnumerable<FilterInfo> GetFilters(HttpConfiguration configuration, HttpActionDescriptor actionDescriptor)
    {
        var filters = base.GetFilters(configuration, actionDescriptor);

        foreach (var filter in filters)
        {
            container.BuildUp(filter.Instance.GetType(), filter.Instance);
        }

        return filters;
    }
}

and I then have added to my UnityConfig.cs

            public static void RegisterFilterProviders(IUnityContainer UnityDependencyResolver)
    {
        var providers = GlobalConfiguration.Configuration.Services.GetFilterProviders().ToList();

        GlobalConfiguration.Configuration.Services.Add(
            typeof(IFilterProvider),
            new UnityActionFilterProvider(UnityDependencyResolver));

        var defaultprovider = providers.First(p => p is ActionDescriptorFilterProvider);

        GlobalConfiguration.Configuration.Services.Remove(typeof(IFilterProvider), defaultprovider);
    }

which I then call in my Startup.cs

   public void Configuration(IAppBuilder app)
    {
        HttpConfiguration = new HttpConfiguration();

        LoggingConfig.RegisterLogger();

        ConfigureOAuth(app);

        var unityContainer = UnityConfig.GetConfiguredContainer();

        HttpConfiguration.DependencyResolver = new UnityDependencyResolver(unityContainer);

        //for DI in the filters
        UnityConfig.RegisterFilterProviders(unityContainer);

        AreaRegistration.RegisterAllAreas();

        WebApiConfig.Register(HttpConfiguration);
        app.UseCors(CorsOptions.AllowAll);
        app.UseWebApi(HttpConfiguration);
    }

Finally, I have the following filter (Note: I have also tried this as an ActionFilter to see if this made a difference)

public class HasPermissionAttribute : AuthorizationFilterAttribute
{
    [Dependency]
    public UserPermissionService UserService { get; set; }


    public override void OnAuthorization(HttpActionContext actionContext)
    {

    }

}

However, the UserService is null when this is being hit? Any ideas on what I am doing wrong here please?

Upvotes: 0

Views: 267

Answers (1)

Matthew Flynn
Matthew Flynn

Reputation: 3941

Hopefully this will help someone, someday.

Basically it was all down to the fact I was using OAuth with the API.

Therefore I simply needed to ensure the configuration was passed across with the filters by editing the startup.cs as follows;

        HttpConfiguration = new HttpConfiguration();

        LoggingConfig.RegisterLogger();

        ConfigureOAuth(app);

        var unityContainer = UnityConfig.GetConfiguredContainer();

        HttpConfiguration.DependencyResolver = new UnityDependencyResolver(unityContainer);

        //for DI in the filters
        UnityConfig.RegisterFilterProviders(unityContainer, HttpConfiguration);

where the registration was simply then ammended with;

    public static void RegisterFilterProviders(IUnityContainer UnityDependencyResolver, HttpConfiguration configuration)
    {
        var providers = configuration.Services.GetFilterProviders().ToList();

        configuration.Services.Add(
            typeof(IFilterProvider),
            new UnityActionFilterProvider(UnityDependencyResolver));

        var defaultprovider = providers.First(p => p is ActionDescriptorFilterProvider);

        configuration.Services.Remove(typeof(IFilterProvider), defaultprovider);
    }

Upvotes: 1

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