Conditions:
Autofac: 4.9.1
.NET Framework: 4.7.2
I have a generic command handler:
public interface ICommand<TResult> : IValidatableObject
{
}
public interface ICommandHandler<TCommand, TResult>
where TCommand : ICommand<TResult>, IValidatableObject
{
TResult Handle(TCommand command);
}
I have a decorator that I want to use for multiple, but not all, implementations of the ICommandHandler (I am going to use a custom attribute to differentiate handlers):
public sealed class LoggingDecorator<TCommand, TResult> : ICommandHandler<TCommand, TResult>
where TCommand : ICommand<TResult>, IValidatableObject
{
private readonly ICommandHandler<TCommand, TResult> _handler;
public LoggingDecorator(ICommandHandler<TCommand, TResult> handler)
{
_handler = handler;
}
public TResult Handle(TCommand command)
{
var test = 0;
return _handler.Handle(command);
}
}
I am trying to register them with AutoFac as follows:
builder.RegisterAssemblyTypes(ThisAssembly)
.AsClosedTypesOf(typeof(ICommandHandler<,>))
.AsImplementedInterfaces();
builder.RegisterGenericDecorator(
decoratorType: typeof(LoggingDecorator<,>),
serviceType: typeof(ICommandHandler<,>),
condition: _decoratorContext =>
{
return false; // true;
});
Seems like the condition is ignored, the decorator is "assigned" to all handlers always.
Have I mis-configured the registration in AutoFac? Or did I miss something else?
How to achieve that the decorator is not registered if the condition returns 'false' in RegisterGenericDecorator method ?
Autofac 4.9.1 is a pretty old version now (3+ yrs). I know that some behaviour around decorator conditions was fixed in v6.0.0; see this issue where upgrading fixed someone's problem that sounds similar to yours.
I'd suggest upgrading to the latest version; if upgrading doesn't fix it, put together a minimal repro and raise an issue on our github repo.
Related
I've a java binding for android which somewhat works bar the new feature I'm trying to integrate with. Only now I have realised that the intended callback is not happening. Here are the classes (decompiled to java) in question:
At the top level we have
public interface MyPackage {
MyPackage.Companion Companion = MyPackage.Companion.$$INSTANCE;
public static final class Companion {
#Nullable
private static MyEventHandler myEventHandler;
// $FF: synthetic field
static final MyPackage.Companion $$INSTANCE;
#Nullable
public final MyEventHandler getMyEventHandler() {
return myEventHandler;
}
public final void setMyEventHandler(#Nullable MyEventHandler var1) {
myEventHandler = var1;
}
private Companion() {
}
static {
MyPackage.Companion var0 = new MyPackage.Companion();
$$INSTANCE = var0;
}
}
}
MyEventHandler class:
public abstract class MyEventHandler {
public abstract void handleEvent(#NotNull String var1, #NotNull Properties var2);
}
Properties class:
import java.util.Map;
public class Properties extends r {
public Properties() {
}
Properties(Map<String, Object> var1) {
super(var1);
}
public Properties a(String var1, Object var2) {
super.b(var1, var2);
return this;
}
}
and the problematic r class:
public class r implements Map<String, Object> {
private final Map<String, Object> a;
various implementations...
}
So I noticed the issue when I couldnt override the HandleEvent method at the integration level and started looking at the Binding logs and found:
Warning=>
BINDINGSGENERATOR: Warning BG8801: Invalid parameter type MyPackage...Properties in method HandleEvent in managed type MyPackage.MyEventHandler. (BG8801)
And in build logs:
message BG0000: warning BG8102: Class MyPackage....Properties has unknown base type MyPackage....r.
warning BG8801: Invalid parameter type MyPackage...Properties in method HandleEvent in managed type MyPackage.MyEventHandler.
As it was obvious r is an obfuscated class I need to make chagnes to my Metadata so I went ahead and popped in:
<attr path="/api/package[#name='MyPackage']/class[#name='r']" name="obfuscated">false</attr>
Which resulted in the R being generated but now I get the 5 following compile error:
Error CS0535: 'R' does not implement interface member 'IMap.EntrySet()' (CS0535)
Error CS0738: 'R' does not implement interface member 'IMap.KeySet()'. 'R.KeySet()' cannot implement 'IMap.KeySet()' because it does not have the matching return type of 'ICollection'. (CS0738)
Error CS0535: 'R' does not implement interface member 'IMap.Put(Object?, Object?)' (CS0535)
Error CS0535: 'R' does not implement interface member 'IMap.PutAll(IDictionary?)' (CS0535)
Error CS0738: 'R' does not implement interface member 'IMap.Values()'. 'R.Values()' cannot implement 'IMap.Values()' because it does not have the matching return type of 'ICollection'. (CS0738)
I tried to make a managed return using
<attr path="/api/package[#name='MyPackage']/class[#name='r']/method[#name='entrySet' and count(parameter)=0]" name="managedReturn">Java.Util.IMap</attr>
With same number of compile error as above. Then I tried removing the node using:
<remove-node path="/api/package[#name='MyPackage']/class[#name='r']/method[#name='entrySet']"/>
Still no luck. :(
What am I missing here? Any pointers/suggestions will be appreciated!
It seems like you are trying to expose a Map to C# and as you stated, Java Generics are not handled very well.
In a very popular social network you received an answer from #mattleibow. I do not take credit for his answer but I went to check nonetheless and it seems fine.
If you look at the description of the Java.Lang.HashMap type
https://learn.microsoft.com/en-us/dotnet/api/java.util.hashmap?view=xamarin-android-sdk-9 it's a good candidate for you to expose.
You can also try with the corresponding interface for better safety https://learn.microsoft.com/en-us/dotnet/api/java.util.imap?view=xamarin-android-sdk-9
If it works you will still have to cast the types yourself.
Please answer to the comment to say that problem is solved for the sake of future generations arriving on this post :D
Credit is not mine so don't give it to me :-)
John,
I got arround fixing it by providing implementation of the the said methods in a partial class. Basically added a new file called R.cs under Additions folder as follows:
namespace YourNameSpace
{
public partial class R
{
public void PutAll(System.Collections.IDictionary p0)
{
PutAll(p0);
}
public Java.Lang.Object Put(Java.Lang.Object key, Java.Lang.Object value)
{
return Put(key, value);
}
public System.Collections.ICollection EntrySet()
{
return EntrySet();
}
public System.Collections.ICollection KeySet()
{
return KeySet();
}
public System.Collections.ICollection Values()
{
return Values();
}
}
}
I couldn't get it to work by adding XML transformation, but I think there was some tooling issue.
Below is my code. I try to convert below code from asp.net to asp.net core. But in asp.net core in last line ConvertTo is showing error because Get(key) does not have definition of ConvertTo. Don't know what is the problem.
I am unable to find any solution how can i write below code in asp.net core?
public static T Get<T>(string key)
{
if (!Exists(key))
{
throw new ArgumentException(String.Format("No such key in the AppSettings: '{0}'", key));
}
return ConfigurationManager.AppSettings.Get(key).ConvertTo<T>(new CultureInfo("en-US"));
}
Thanks in advance.
I suggest you carefully reading the documentation first. In .NET Core the way how we work with configuration is changed significantly ( different source using, mapping to POCO objects , etc).
In your case you may simply use ConfigurationBinder’s GetValue<T> extension method instead of implementing own method for value conversion:
IConfiguration.GetValue - extracts the value with the specified key
and converts it to type T.
Configuration in .net Core is now built on top of POCO's or IOptions for the most part. You don't get individual keys but instead you build up settings classes. Previously you had to either build a CustomConfiguration class or you would prefix AppSettings to "group them". Not anymore! If you take the approach of using IOptions it works something like the following.
You have your appSettings.json look like the following :
{
"myConfiguration": {
"myProperty": true
}
}
You then make up a POCO that matches your configuration. Something like this :
public class MyConfiguration
{
public bool MyProperty { get; set; }
}
Then in your startup.cs you need to load your configuration into an options object. It will end up looking pretty similar to the following.
public class Startup
{
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
.AddEnvironmentVariables();
Configuration = builder.Build();
}
public IConfigurationRoot Configuration { get; }
public void ConfigureServices(IServiceCollection services)
{
services.Configure<MyConfiguration>(Configuration.GetSection("myConfiguration"));
}
}
Then the DI is all set up to inject an IOptions objects. You would then inject it into a controller like so :
public class ValuesController : Controller
{
private readonly MyConfiguration _myConfiguration;
public ValuesController(IOptions<MyConfiguration> myConfiguration)
{
_myConfiguration = myConfiguration.Value;
}
}
There is other ways to do this that don't use the IOptions object and you only inject in the POCO to your controllers. Some people (including me) prefer this method. You can read more here : http://dotnetcoretutorials.com/2016/12/26/custom-configuration-sections-asp-net-core/
And of course the documentation link for the official docs are here : https://learn.microsoft.com/en-us/aspnet/core/fundamentals/configuration
How do I force AutoFixture, that has been configured with AutoConfiguredMoqCustomization, to automatically mock interfaces and its read-only properties?
To make things clear, let's assume I have such an interface:
public interface A {
int Property {get;}
}
and such class:
public class SomeClass {
public SomeClass(A dependency) {}
}
What I want is to have dependency resolved to a mock that will return something in dependency.Property:
var fixture = new Fixture().Customize(new AutoConfiguredMoqCustomization());
var sut = fixture.Create<SomeClass>(); // <- dependency passed to SomeClass' constructor will have .Property returning null
This is due to a bug introduced in Moq 4.2.1502.911, where SetupAllProperties overrides previous setups done on get-only properties.
Here's a simpler repro:
public interface Interface
{
string Property { get; }
}
var a = new Mock<Interface>();
a.Setup(x => x.Property).Returns("test");
a.SetupAllProperties();
Assert.NotNull(a.Object.Property);
This is sort of what AutoFixture does behind the scenes to create an instance of Interface. This test fails with versions of Moq equal to or greater than 4.2.1502.911, but passes with lower versions.
Simply run this on the Package Manager Console:
install-package Moq -version 4.2.1409.1722
This bug is being tracked here: https://github.com/Moq/moq4/issues/196
I am actually working in an ASP.Net MVC 4 web application where we are using NInject for dependency injection. We are also using UnitOfWork and Repositories based on Entity framework.
We would like to use Quartz.net in our application to start some custom job periodically. I would like that NInject bind automatically the services that we need in our job.
It could be something like this:
public class DispatchingJob : IJob
{
private readonly IDispatchingManagementService _dispatchingManagementService;
public DispatchingJob(IDispatchingManagementService dispatchingManagementService )
{
_dispatchingManagementService = dispatchingManagementService ;
}
public void Execute(IJobExecutionContext context)
{
LogManager.Instance.Info(string.Format("Dispatching job started at: {0}", DateTime.Now));
_dispatchingManagementService.DispatchAtomicChecks();
LogManager.Instance.Info(string.Format("Dispatching job ended at: {0}", DateTime.Now));
}
}
So far, in our NInjectWebCommon binding is configured like this (using request scope):
kernel.Bind<IDispatchingManagementService>().To<DispatchingManagementService>();
Is it possible to inject the correct implementation into our custom job using NInject ? and how to do it ? I have read already few posts on stack overflow, however i need some advises and some example using NInject.
Use a JobFactory in your Quartz schedule, and resolve your job instance there.
So, in your NInject config set up the job (I'm guessing at the correct NInject syntax here)
// Assuming you only have one IJob
kernel.Bind<IJob>().To<DispatchingJob>();
Then, create a JobFactory: [edit: this is a modified version of #BatteryBackupUnit's answer here]
public class NInjectJobFactory : IJobFactory
{
private readonly IResolutionRoot resolutionRoot;
public NinjectJobFactory(IResolutionRoot resolutionRoot)
{
this.resolutionRoot = resolutionRoot;
}
public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
// If you have multiple jobs, specify the name as
// bundle.JobDetail.JobType.Name, or pass the type, whatever
// NInject wants..
return (IJob)this.resolutionRoot.Get<IJob>();
}
public void ReturnJob(IJob job)
{
this.resolutionRoot.Release(job);
}
}
Then, when you create the scheduler, assign the JobFactory to it:
private IScheduler GetSchedule(IResolutionRoot root)
{
var schedule = new StdSchedulerFactory().GetScheduler();
schedule.JobFactory = new NInjectJobFactory(root);
return schedule;
}
Quartz will then use the JobFactory to create the job, and NInject will resolve the dependencies for you.
Regarding scoping of the IUnitOfWork, as per a comment of the answer i linked, you can do
// default for web requests
Bind<IUnitOfWork>().To<UnitOfWork>()
.InRequestScope();
// fall back to `InCallScope()` when there's no web request.
Bind<IUnitOfWork>().To<UnitOfWork>()
.When(x => HttpContext.Current == null)
.InCallScope();
There's only one caveat that you should be aware of:
With incorrect usage of async in a web request, you may mistakenly be resolving a IUnitOfWork in a worker thread where HttpContext.Current is null. Now without the fallback binding, this would fail with an exception which would show you that you've done something wrong. With the fallback binding however, the issue may present itself in an obscured way. That is, it may work sometimes, but sometimes not. This is because there will be two (or even more) IUnitOfWork instances for the same request.
To remedy this, we can make the binding more specific. For this, we need some parameter to tell us to use another than InRequestScope(). Have a look at:
public class NonRequestScopedParameter : Ninject.Parameters.IParameter
{
public bool Equals(IParameter other)
{
if (other == null)
{
return false;
}
return other is NonRequestScopedParameter;
}
public object GetValue(IContext context, ITarget target)
{
throw new NotSupportedException("this parameter does not provide a value");
}
public string Name
{
get { return typeof(NonRequestScopedParameter).Name; }
}
// this is very important
public bool ShouldInherit
{
get { return true; }
}
}
now adapt the job factory as follows:
public class NInjectJobFactory : IJobFactory
{
private readonly IResolutionRoot resolutionRoot;
public NinjectJobFactory(IResolutionRoot resolutionRoot)
{
this.resolutionRoot = resolutionRoot;
}
public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
return (IJob) this.resolutionRoot.Get(
bundle.JobDetail.JobType,
new NonrequestScopedParameter()); // parameter goes here
}
public void ReturnJob(IJob job)
{
this.resolutionRoot.Release(job);
}
}
and adapt the IUnitOfWork bindings:
Bind<IUnitOfWork>().To<UnitOfWork>()
.InRequestScope();
Bind<IUnitOfWork>().To<UnitOfWork>()
.When(x => x.Parameters.OfType<NonRequestScopedParameter>().Any())
.InCallScope();
This way, if you use async wrong, there'll still be an exception, but IUnitOfWork scoping will still work for quartz tasks.
For any users that could be interested, here is the solution that finally worked for me.
I have made it working doing some adjustment to match my project. Please note that in the method NewJob, I have replaced the call to Kernel.Get by _resolutionRoot.Get.
As you can find here:
public class JobFactory : IJobFactory
{
private readonly IResolutionRoot _resolutionRoot;
public JobFactory(IResolutionRoot resolutionRoot)
{
this._resolutionRoot = resolutionRoot;
}
public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
try
{
return (IJob)_resolutionRoot.Get(
bundle.JobDetail.JobType, new NonRequestScopedParameter()); // parameter goes here
}
catch (Exception ex)
{
LogManager.Instance.Info(string.Format("Exception raised in JobFactory"));
}
}
public void ReturnJob(IJob job)
{
}
}
And here is the call schedule my job:
public static void RegisterScheduler(IKernel kernel)
{
try
{
var scheduler = new StdSchedulerFactory().GetScheduler();
scheduler.JobFactory = new JobFactory(kernel);
....
}
}
Thank you very much for your help
Thanks so much for your response. I have implemented something like that and the binding is working :):
public IJob NewJob(TriggerFiredBundle bundle, IScheduler scheduler)
{
var resolver = DependencyResolver.Current;
var myJob = (IJob)resolver.GetService(typeof(IJob));
return myJob;
}
As I told before I am using in my project a service and unit of work (based on EF) that are both injected with NInject.
public class DispatchingManagementService : IDispatchingManagementService
{
private readonly IUnitOfWork _unitOfWork;
public DispatchingManagementService(IUnitOfWork unitOfWork)
{
_unitOfWork = unitOfWork;
}
}
Please find here how I am binding the implementations:
kernel.Bind<IUnitOfWork>().To<EfUnitOfWork>()
kernel.Bind<IDispatchingManagementService>().To<DispatchingManagementService>();
kernel.Bind<IJob>().To<DispatchingJob>();
To resume, the binding of IUnitOfWork is done for:
- Eevery time a new request is coming to my application ASP.Net MVC: Request scope
- Every time I am running the job: InCallScope
What are the best practices according to the behavior of EF ? I have find information to use CallInScope. Is it possible to tell NInject to get a scope ByRequest everytime a new request is coming to the application, and a InCallScope everytime my job is running ? How to do that ?
Thank you very much for your help
My app flow is as follows (simplified for clarity):
User GETs a page from "/page1"
User performs actions on the page (adds text, clicks, etc..), while Signalr communicates this data to the server, which performs heavy calculations in the background, and the results of those are returned to the page (lets call those "X").
When the user is finished with the page, he clicks a link to "/page2", that is returned by Nancy. This page is built using a Model that is dependent on X.
So, how do I build that Model based on X? How can signalr write to the user session in a way that Nancy can pick up on?
(I'm looking for a "clean" way)
Pending formal integration of Signalr & Nancy, this is what I came with. Basically, I share an IOC container between the two, and use an object (singleton lifetime) that maps users to state.
How to share an IOC container using the built in TinyIOC:
Extend Signalr's DefaultDependencyResolver
public class TinyIoCDependencyResolver : DefaultDependencyResolver
{
private readonly TinyIoCContainer m_Container;
public TinyIoCDependencyResolver(TinyIoCContainer container)
{
m_Container = container;
}
public override object GetService(Type serviceType)
{
return m_Container.CanResolve(serviceType) ? m_Container.Resolve(serviceType) : base.GetService(serviceType);
}
public override IEnumerable<object> GetServices(Type serviceType)
{
var objects = m_Container.CanResolve(serviceType) ? m_Container.ResolveAll(serviceType) : new object[] { };
return objects.Concat(base.GetServices(serviceType));
}
}
Replace Signalr's default DependencyResolver with our new one
public class Bootstrapper : DefaultNancyBootstrapper
{
protected override void ApplicationStartup(TinyIoCContainer container, IPipelines pipelines)
{
CookieBasedSessions.Enable(pipelines);
// Replace UserToStateMap with your class of choice
container.Register<IUserToStateMap, UserToStateMap>();
GlobalHost.DependencyResolver = new TinyIoCDependencyResolver(container);
RouteTable.Routes.MapHubs();
}
}
Add IUserToStateMap as a dependency in your hubs and Nancy modules
public class MyModule : NancyModule
{
public MyModule(IUserToStateMap userToStateMap)
{
Get["/"] = o =>
{
var userId = Session["userId"];
var state = userToStateMap[userId];
return state.Foo;
};
}
}
public class MyHub : Hub
{
private readonly IUserToStateMap m_UserToStateMap;
public MyHub(IUserToStateMap userToStateMap)
{
m_UserToStateMap = userToStateMap;
}
public string MySignalrMethod(string userId)
{
var state = userToStateMap[userId];
return state.Bar;
}
}
What I would really want, is a way to easily share state between the two based on the connection ID or something like that, but in the meantime this solution works for me.
Did you arrive hear looking for a simple example of how to integrate Nancy and SignalR? I know I did.
Try this question instead (I self-answered it).
SignalR plus NancyFX : A simple but well worked example