I have a piece of code that encapsulates functionality that isn't specific to Orchard. However i need to make it available in Orchard via dependency injection. So, I built up an Autofac Module that registers all components (types), but I can't find a way to inform Orchard's Autofac Container about it.
From what i red, there are two ways to add a module to a container:
By supplying the module at to the ContainerBuilder (usually at start-up),
Or by updating the already built Container at runtime with a ContainerBuilder
I can approach the problem in the first way, but I rather do a variant of the second if there is such?
Just add a class deriving from Autofac.Module to your Orchard module and that's it. It will get automatically picked by Orchard during the container construction.
Piotr Szmyd's answer is fundamentally correct, but here's some more detail:
Your Orchard Module is the new .csproj that you've added to the Orchard.sln
Add Autofac as a reference to that csproj (make sure you use the version included with Orchard - not nuget. See here for more details about that problem)
Then add a class that derives from Autofac.Module and which implements Load(ContainerBuilder).
e.g.
using System;
using Autofac;
namespace MyCustom.Module.Namespace
{
public class LoaderModule : Autofac.Module
{
protected override void Load(ContainerBuilder builder)
{
builder.RegisterType<MyClass>().As<IMyInterface>();
}
}
}
As an additional note:
The Autofac registration code only gets invoked at application startup time.
If you are running with the site sitting locally in IIS and the code in VS, then the dynamic compilation nature of Orcahrd means that when you recompile the code, the application doesn't stop.
So in order for this Autofac registration code to be hit (and also for any channges to it to take effect) you have to iisreset to kill the application, so that it reloads the Autofac Registrations.
Related
If I in my AppHostBase descendant (web api project ) use container.AutoWire(this), it will result in a NullReferenceException in the ServiceStack code, if I am using a web project, thus starting it with the CreateHostBuilder(args).Build().Run(); in the main method.
The error is reproduced in this Github project: https://github.com/tedekeroth/ServiceStackAutoWireTest
The error occurs in AppHostBase.Netcore.Cs, line 158:
If I remove the container.AutoWire(this); in TestAppHost.cs, the error goes away, but then the dependency injection does not work, meaning the Logger in TestAppHostproperty is not assigned:
I am not sure why this happens or what I can do about it. I'd appreciate some input, thanks.
Setup
Visual Studio 2019
Target framework: .NET 5.0 (Console Application)
Project SDK: Microsoft.NET.Sdk.Web
ServiceStack 5.11.0
The IOC AutoWire API attempts to autowire all public property dependencies of an object which is definitely something you should never attempt to do with the AppHost which encapsulates the configuration and behavior of your ServiceStack App where indiscriminatingly overriding every public property is going to leave it in a corrupted state.
Registering your AppHost in the IOC shouldn't be necessary as it's available everywhere via the HostContext.AppHost singleton. It's also a bad idea trying to reference any type defined in your Host Project, (the AppHost being the canonical example) since it creates a circular reference to your Host project in your App logic dependencies which shouldn't have any references back to its Host project, your Host project is supposed to reference all your projects .dll's, configure your App's and all its dependencies, not the other way around.
Should you need access to any Plugins it's recommended to use the GetPlugin<T>() API in your Service for optional plugins or AssertPlugin<T>() for required plugins. If you need to resolve any deps manually you can use TryResolve<T>() API in your Service class. For any of your App's custom config I'd recommend registering them in a custom AppConfig class for your Services to access like any other dependencies.
Otherwise if you really need access to the AppHost you can use the HostContext.AppHost singleton. If you absolutely need to have the AppHost in the IOC, just register it as a normal singleton, i.e. don't try to autowire it:
container.Register<IAppHost>(c => this);
However as mentioned earlier I'd strongly advise against it, have everything your App needs in a custom class (e.g. AppConfig) that is accessed like a normal dependency.
I have an ASP.NET MVC 5 project where I need to use a custom web-service based e-mail service (long story! Can't change it, though).
I wrapped up the e-mail web service into a separate assembly and packaged all the dependencies in there.
In my ASP.NET MVC 5 app, I'm using Ninject for dependency injection, and it works really well inside the MVC project - the controllers get their dependencies injected "magically" , and it's a joy to use.
But now: for my e-mail sending component, I'd like to write a "mock" or simulator for use locally when doing development. So basically, I would need to be able to bind the IMailService to both the MailService (real implementation), as well as the MailServiceSimulator (my dummy implementation). Ninject supports that, no problem:
Bind<IMailService>().To<MailService>().Named("Production");
Bind<IMailService>().To<MailServiceSimulator>().Named("Simulator");
BUT: the problem is this: I register all the dependencies with Ninject in the MVC application (in the NinjectWebCommon class in App_Startup) - but I'd like to be able to have a factory class in my "mail service" project that can be told to return a real implementation - or the simulator - for the mail sending component. But how can I get access to the Ninject kernel in order to get the desired service?
Somehow, I'd need to be able to do either
return kernel.Get<IMailService>("Production");
if the real implementation is desired, or
return kernel.Get<IMailService>("Simulator");
if the development-time simulator for the IMailService should be used.
Since my MVC app already uses the "MailService" assembly as a reference, I cannot really make the "MailService" use the "MVC" project as a reference.... so how can I access the Ninject kernel (that gets created inside the "MVC" assembly at startup) from within a referenced "MailService" assembly?? Seems I'm going in circles, one assembly requiring the other and then the other requiring the first one again as a dependency.....
Any ideas?
Accessing the Kernel, or doing DI business, in your MailService project seems like a leaky abstraction.
Assuming the "Production/Simulator" switch is located in the appSettings as a "MailSwitch" setting, you may leave out the named bindings and go for :
Bind<IMailService>().To<MailService>()
.When(r => ConfigurationManager.AppSettings.Get("MailSwitch")=="Production");
Bind<IMailService>().To<MailServiceSimulator>()
.When(r => ConfigurationManager.AppSettings.Get("MailSwitch")=="Simulator");
I am trying to properly use Ninject to inject log4net logging into my MVC3 application. I am using the Ninject.MVC3 package, so I have the NinjectMVC3 class that automatically extends the App_Start method and contains the RegisterServices method that binds all dependencies. I also have the Ninject.Extensions.Logging.Log4Net package, but I don't know how to use it. I already know how to configure log4net in my web.config, but don't know how to use this extension for DI.
I have read all the following articles/posts, but none of them seem to define how to properly setup a project for DI logging.
At http://dotnetdarren.wordpress.com/2010/07/29/logging-in-mvc-part-4-log4net/, Darren
provides a great article, but doesn't seem to deal with DI (at least I don't see it).
At Using Ninject to fill Log4Net Dependency,
Remo Gloor states here that the extensions should provide all that's needed for implementation, but it doesn't show the code of how to instantiate it.
The documentation for ninject.extensions.logging at https://github.com/ninject/ninject.extensions.logging/wiki/Using is very limited at best. I have re-read it many times, and still don't see how to use bind the injection in the NinjectMVC3 class, or concrete examples of how to call the logger from my controller class for example.
At the most promising article, Moosaka provides some great code at Ninject.Extensions.Logging.Log4net unexpected behavior, but when I try it, I get a compile error in the LoggerFactory at ILogger logger = new Logger(type); stating "Cannot access protected constructor 'Logger' here". Also, he states to "Tuck this whole mess away into a separate class library". Does that mean as a whole separate project?
I'm just getting lost in all the differing options and dated posts and would like any input on how to use Dependancy Injection with Ninject and Log4Net in my MVC3 project. Also, if it matters, all of my Ninject code is in my domain project, but the logging needs done from both the domain and web project (and mocked in my unit tests). Any help is appreciated.
You shouldn't have to configure anything except the normal log4net config.
All you have to do is to inject a ILogger wherever you want to log.
https://github.com/ninject/ninject.extensions.logging/wiki/Using
While developing web project using ASP.NET MVC, I came up against a coupling problem.
When I build custom controller factory (or dependency resolver if using MVC 3), I need this factory to know somehow where to get dependencies from. Here's my code:
//from Global.asax.cs
DependencyResolver.SetResolver(new StructureMapControllerFactory());
class StructureMapControllerFactory: IDependencyResolver {
Container repositories;
public StructureMapControllerFactory()
{
repositories = new RepositoriesContainer();
}
//... rest of the implementation
}
class RepositoriesContainer: Container
{
public RepositoriesContainer()
{
For<IAccountRepository>().Use<SqlAccountRepository>();
//...
}
}
StructureMapControllerFactory class is responsible for injecting dependencies into a controller. As I said, it needs to know where to find these dependencies (I mean concrete classes, like services and repositories implementations).
I have a separate class library called MySite.Data, where all the implementation details live. Contracts, like IAccountRepository, live in library MySite.Contracts. Now, if I reference this MySite.Data library directly from MVC project, there will be a dependency between my site and implementation of its data retrieval. The question is how can I remove it? What are best practices in this situation?
I'm sure it does have a bunch of workarounds, just I haven't found any yet.
Well, as I see it, you can't do exactly that. Your MVC project really really needs to know about concrete classes it is going to use.
You will anyway have to provide those container registrations somewhere and you'll get the dependency on the project/assembly where that type is defined. Shortly, you have to reference MySite.Data from MVC project. Like that:
MySite.Data knows nothing about MVC project
MVC project knows the concrete repositories types to provide correct container registrations.
You can make life simpler with StructureMap Registry objects but you need to include those Registries somewhere as well. Typically those are in the main project or some "StructureMap-adapter" project but you'd need to make reference anyway.
I'd advise that you:
Use MVC3 and drop your custom IControllerFactory if you only use it for DI into your Controllers.
Use StructureMap Registry objects to provide each and every IoC registration ever needed.
Use StructureMap Assembly scanning capabilities to provide components discovery.
Use something much more common as a DependencyResolver, i.e. not a StructureMapControllerFactory but a CommonServiceLocator with StructureMap adapter instead.
Try to abstract from StructureMap itself inside your main app.
And, of course, don't be afraid of making references inside the main project - they have nothing about coupling. It doesn't decrease maintainability. But the wrong architecture does, so be worried about that, not simple reference.
I am creating a new application using asp.net mvc, I'm using munq IOC container as my dependency injection..The issue is i want to create a new project for dependency resolution where i can register all the controllers of mvc project and the repositories of infrastructure project..I have to add Dependency Resolution project as a reference in my mvc app as thats the starting point... but the prob is in order to register the controllers in this separate app i need to have the reference of the mvc in the dependency Resolution project itself...but such a thing is not possible because that would cause a circular reference..
so how to resolve this issue? or what is the best way of managing the dependency resolution?
I don't want to end up registering everything in the Global.asax
Get the latest version from the source tab at Munq.Codeplex.com. This version has a view improvements and it is the version I am most familiar with, and I wrote it.
To prevent circular references for registration, create a class project that includes reverences to Munq.Interfaces and the interfaces and implementations you wish to register.
Create a class that implements IMunqConfig. It has one method void RegisterIn(IIocContainer container). Implement this method.
public class MyRegistration : IMuncConfig
{
public void RegisterIn(IIocContainer container)
{
container.Register<IMyInterface>(c => new MyImplementation());
// OR
container.Register<IMyInterface, MyImplementation>();
// Repeat as required for each thing to register
}
}
Then in global.asax
protected void Application_Start()
{
IocContainer = new Container();
Munq.COnfigurationLoader.FindAndRegisterDependencies(container);
AreaRegistration.RegisterAllAreas();
RegisterRoutes(RouteTable.Routes);
}
This will search the bin directory for any dlls that have classes implementing IMunqConfig and execute the RegisterIn method on each. So just drop the registration dlls into the bin directory and registration happens automagically :)
Matthew
i want to create a new project for dependency resolution where i can
register all the controllers of mvc project and the repositories of
infrastructure project.
I wouldn't register MVC controllers in the same project as your repositories. The MVC app should "own" its composition, including registering its internal dependencies.
Registrations for your infrastructure project should ideally be in that project, especially if it's not something you're going to make available to other projects that use different DI containers. If that project needs to remain DI-agnostic then maybe it might make sense to separate DI registration into a separate project.
But I definitely wouldn't make a service (like your repository) responsible for registering the internal dependencies of its consumers (like your MVC app.)