The type IApiOutputCache does not have an accessible constructor.

[KingR1]

I install Strathweb.CacheOutput.WebApi2 using Package Manager Console. Try to run my WebAPI project - get error : "Attempt by security transparent method 'System.Web.Http.GlobalConfiguration.get_Configuration()' to access security critical type 'System.Web.Http.HttpConfiguration' failed."

So i made search for solution and stopped at this post http://www.dotnetspider.com/resources/45576-Attempt-by-security-transparent-method.aspx So i do following : Update-Package Microsoft.AspNet.WebApi -Pre.

Then i get problem with CacheOutput :

{"message":"An error has occurred.","exceptionMessage":"Resolution of the dependency failed, type = \"WebApi.OutputCache.Core.Cache.IApiOutputCache\", name = \"(none)\".\r\nException occurred while: while resolving.\r\nException is: InvalidOperationException - The type IApiOutputCache does not have an accessible constructor.\r\n-----------------------------------------------\r\nAt the time of the exception, the container was:\r\n\r\n Resolving WebApi.OutputCache.Core.Cache.IApiOutputCache,(none)\r\n","exceptionType":"Microsoft.Practices.Unity.ResolutionFailedException","stackTrace":" at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, Object existing, String name, IEnumerable1 resolverOverrides)\r\n at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, String name, IEnumerable1 resolverOverrides)\r\n at Microsoft.Practices.Unity.UnityContainer.Resolve(Type t, String name, ResolverOverride[] resolverOverrides)\r\n at Microsoft.Practices.Unity.UnityContainerExtensions.Resolve(IUnityContainer container, Type t, ResolverOverride[] overrides)\r\n at Microsoft.Practices.Unity.WebApi.UnityDependencyResolver.SharedDependencyScope.GetService(Type serviceType)\r\n at WebApi.OutputCache.V2.CacheOutputConfiguration.GetCacheOutputProvider(HttpRequestMessage request)\r\n at WebApi.OutputCache.V2.CacheOutputAttribute.EnsureCache(HttpConfiguration config, HttpRequestMessage req)\r\n at WebApi.OutputCache.V2.CacheOutputAttribute.OnActionExecuting(HttpActionContext actionContext)\r\n at WebApi.OutputCache.V2.CacheOutputAttribute.System.Web.Http.Filters.IActionFilter.ExecuteActionFilterAsync(HttpActionContext actionContext, CancellationToken cancellationToken, Func1 continuation)\r\n at System.Web.Http.Tracing.Tracers.ActionFilterTracer.<>cDisplayClass3.b0()\r\n at System.Web.Http.Tracing.ITraceWriterExtensions.TraceBeginEndAsync[TResult](ITraceWriter traceWriter, HttpRequestMessage request, String category, TraceLevel level, String operatorName, String operationName, Action1 beginTrace, Func1 execute, Action2 endTrace, Action1 errorTrace)\r\n at System.Web.Http.Tracing.Tracers.ActionFilterTracer.System.Web.Http.Filters.IActionFilter.ExecuteActionFilterAsync(HttpActionContext actionContext, CancellationToken cancellationToken, Func1 continuation)\r\n at System.Web.Http.Controllers.ActionFilterResult.<>c__DisplayClassb.<>c__DisplayClassd.<InvokeActionWithActionFilters>b__9()\r\n at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()\r\n at System.Web.Http.Controllers.ExceptionFilterResult.d0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Web.Http.Controllers.ExceptionFilterResult.d0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()\r\n at System.Web.Http.Tracing.Tracers.HttpControllerTracer.<ExecuteAsyncCore>d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()\r\n at System.Web.Http.Tracing.ITraceWriterExtensions.d181.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.d1.MoveNext()","innerException":{"message":"An error has occurred.","exceptionMessage":"The type IApiOutputCache does not have an accessible constructor.","exceptionType":"System.InvalidOperationException","stackTrace":" at Microsoft.Practices.ObjectBuilder2.DynamicMethodConstructorStrategy.ThrowForNullExistingObject(IBuilderContext context)\r\n at lambda_method(Closure , IBuilderContext )\r\n at Microsoft.Practices.ObjectBuilder2.DynamicBuildPlanGenerationContext.<>cDisplayClass1.b0(IBuilderContext context)\r\n at Microsoft.Practices.ObjectBuilder2.DynamicMethodBuildPlan.BuildUp(IBuilderContext context)\r\n at Microsoft.Practices.ObjectBuilder2.BuildPlanStrategy.PreBuildUp(IBuilderContext context)\r\n at Microsoft.Practices.ObjectBuilder2.StrategyChain.ExecuteBuildUp(IBuilderContext context)\r\n at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, Object existing, String name, IEnumerable1 resolverOverrides)"}}

Attribute, that i add to Web API method GET() is next : [CacheOutput(ClientTimeSpan = 50, ServerTimeSpan = 50)]

What can cause problem with CacheOutPut and how to resolve it?

[filipw]

it looks like you are using Unity. Did you register the Dependency Resolver for Unity? Do you have the code for that?

On 18 August 2014 15:37, KingR1 notifications@github.com wrote:

I install Strathweb.CacheOutput.WebApi2 using Package Manager Console. Try to run my WebAPI project - get error : "Attempt by security transparent method 'System.Web.Http.GlobalConfiguration.get_Configuration()' to access security critical type 'System.Web.Http.HttpConfiguration' failed."

So i made search for solution and stopped at this post http://www.dotnetspider.com/resources/45576-Attempt-by-security-transparent-method.aspx So i do following : Update-Package Microsoft.AspNet.WebApi -Pre.

Then i get problem with CacheOutput :

{"message":"An error has occurred.","exceptionMessage":"Resolution of the dependency failed, type = \"WebApi.OutputCache.Core.Cache.IApiOutputCache\", name = \"(none)\".\r\nException occurred while: while resolving.\r\nException is: InvalidOperationException - The type IApiOutputCache does not have an accessible constructor.\r\n-----------------------------------------------\r\nAt the time of the exception, the container was:\r\n\r\n Resolving WebApi.OutputCache.Core.Cache.IApiOutputCache,(none)\r\n","exceptionType":"Microsoft.Practices.Unity.ResolutionFailedException","stackTrace":" at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, Object existing, String name, IEnumerable1 resolverOverrides)\r\n at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, String name, IEnumerable1 resolverOverrides)\r\n at Microsoft.Practices.Unity.UnityContainer.Resolve(Type t, String name, ResolverOverride[] resolverOverrides)\r\n at Microsoft.Practices .Unity.UnityContainerExtensions.Resolve(IUnityContainer container, Type t, ResolverOverride[] overrides)\r\n at Microsoft.Practices.Unity.WebApi.UnityDependencyResolver.SharedDependencyScope.GetService(Type serviceType)\r\n at WebApi.OutputCache.V2.CacheOutputConfiguration.GetCacheOutputProvider(HttpRequestMessage request)\r\n at WebApi.OutputCache.V2.CacheOutputAttribute.EnsureCache(HttpConfiguration config, HttpRequestMessage req)\r\n at WebApi.OutputCache.V2.CacheOutputAttribute.OnActionExecuting(HttpActionContext actionContext)\r\n at WebApi.OutputCache.V2.CacheOutputAttribute.System.Web.Http.Filters.IActionFilter.ExecuteActionFilterAsync(HttpActionContext actionContext, CancellationToken cancellationToken, Func1 continuation)\r\n at System.Web.Http.Tracing.Tracers.ActionFilterTracer.<>cDisplayClass3.b0()\r\n at System.Web.Http.Tracing.ITraceWriterExtensions.TraceBeginEndAsync TResult\r\n at System.Web.Http.Tracing.Tracers.ActionFilterTracer.System.Web.Http.Filters.IActionFilter.ExecuteActionFilterAsync(HttpActionContext actionContext, CancellationToken cancellationToken, Func1 continuation)\r\n at System.Web.Http.Controllers.ActionFilterResult.<>cDisplayClassb.<>cDisplayClassd.b9()\r\n at System.Web.Http.Controllers.ActionFilterResult.d2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter1.GetRe sult()\r\n at System.Web.Http.Controllers.ExceptionFilterResult.d0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Web.Http.Controllers.ExceptionFilterResult.d0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()\r\n at System.Web.Http.Tracing.Tracers.HttpControllerTracer.d5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNoti fication(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()\r\n at System.Web.Http.Tracing.ITraceWriterExtensions.d181.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter1.GetResult()\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.d__1.MoveNext()","innerException":{"message":"An error has occurred.","exceptionMessage":"The type IApiOutputCache does not have an accessible constructor.","exceptionType":"System.InvalidOperationException","stackTrace":" at Microsoft.Practices.ObjectBuilder2.DynamicMethodConstructorStrategy.ThrowForNullExistingObject(IBuilderContext context)\r\n at lambda_method(Closure , IBuilderContext )\r\n at Microsoft.Pract ices.ObjectBuilder2.DynamicBuildPlanGenerationContext.<>cDisplayClass1.b0(IBuilderContext context)\r\n at Microsoft.Practices.ObjectBuilder2.DynamicMethodBuildPlan.BuildUp(IBuilderContext context)\r\n at Microsoft.Practices.ObjectBuilder2.BuildPlanStrategy.PreBuildUp(IBuilderContext context)\r\n at Microsoft.Practices.ObjectBuilder2.StrategyChain.ExecuteBuildUp(IBuilderContext context)\r\n at Microsoft.Practices.Unity.UnityContainer.DoBuildUp(Type t, Object existing, String name, IEnumerable1 resolverOverrides)"}}

Attribute, that i add to Web API method GET() is next : [CacheOutput(ClientTimeSpan = 50, ServerTimeSpan = 50)]

What can cause problem with CacheOutPut and how to resolve it?

— Reply to this email directly or view it on GitHub https://github.com/filipw/AspNetWebApi-OutputCache/issues/89.

[KingR1]

Hi, Filip. Yes, I use Unity and yes, I register it.

[filipw]

looks like your Unity adapter is throwing an exception when it shouldn't. Here you can find a proper implementation of Unity resolver http://www.asp.net/web-api/overview/extensibility/using-the-web-api-dependency-resolver

The caching library will try to grab IApiOutputCache using the following precedence:

• try to load IApiOutputCache from HttpConfiguration.Properties
• try to load IApiOutputCache from DependencyResolver, default to MemoryCache
• If your DependencyResolver throws an error, rather than return a null it will fail - but that is then resolver's fault, as it should always return null

If you can't change the behavior unity resolver, you can always register IApiOutputCache in the HttpConfiguration:

httpConfiguration.CacheOutputConfiguration().RegisterCacheOutputProvider(() => new MemoryCacheDefault());

[filipw]

If you read the Unity article, there is even a highlighted note there :)

    If the GetService method cannot resolve a type, it should return null. If the GetServices method cannot resolve a type, it should return an empty collection object. Don't throw exceptions for unknown types.

which is what your Unity resolver seems to be doing now

[KingR1]

If you can't change the behavior unity resolver, you can always register IApiOutputCache in the HttpConfiguration: httpConfiguration.CacheOutputConfiguration().RegisterCacheOutputProvider(() => new MemoryCacheDefault());

This also doesn't help me after I tried to make some changes in implementation of Unity resolver (firstly i user [Dependency] attribute, now - constructors for repositories)

[filipw]

please provide a repro project, I can have a look then

[KingR1]

If it's allright - please get prototype of my project from here https://drive.google.com/file/d/0B60DXolm0D0GUWxxZG9ZUl9IeDQ/edit?usp=sharing (Connection String is some fake, working link /api/v1/holidays )

[filipw]

the unity dependency resolver you are using is botched because it doesn't handle errors properly (!). Use the one from the article I linked to http://www.asp.net/web-api/overview/extensibility/using-the-web-api-dependency-resolver

public class UnityResolver : IDependencyResolver
{
    protected IUnityContainer container;

    public UnityResolver(IUnityContainer container)
    {
        if (container == null)
        {
            throw new ArgumentNullException("container");
        }
        this.container = container;
    }

    public object GetService(Type serviceType)
    {
        try
        {
            return container.Resolve(serviceType);
        }
        catch (ResolutionFailedException)
        {
            return null;
        }
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        try
        {
            return container.ResolveAll(serviceType);
        }
        catch (ResolutionFailedException)
        {
            return new List<object>();
        }
    }

    public IDependencyScope BeginScope()
    {
        var child = container.CreateChildContainer();
        return new UnityResolver(child);
    }

    public void Dispose()
    {
        container.Dispose();
    }
}

It works I tested it.

Alternatively add the following two lines in your web api configuration (not 1 like I said before :)

        config.CacheOutputConfiguration().RegisterCacheOutputProvider(() => new MemoryCacheDefault());
        config.CacheOutputConfiguration().RegisterDefaultCacheKeyGeneratorProvider(() => new DefaultCacheKeyGenerator());

This also works, even without changing the Unity resolver.

[filipw]

and thanks for providing the repro project - it helped a lot

[KingR1]

Filip, Thanks! Problem is resolved!!! :+1: