I'm using ASP.NET MVC (1.0) and StructureMap (2.5.3), I'm doing a plugin feature where dll's with controller are to be picked up in a folder. I register the controllers with SM (I am able to pick it up afterwards, so I know it's in there)
foreach (string file in path)
{
var assy = System.Reflection.Assembly.LoadFile(file);
Scan(x =>{
x.Assembly(assy);
x.AddAllTypesOf<IController>();
});
}
My problem is with the GetControllerInstance method of my override of DefaultControllerFactory. Everytime I send in enything else than a valid controller (valid in the sense that it is a part of the web project) I get the input Type parameter as null.
I've tried setting up specific routes for it.
I've done a test with Castle.Windsor and there it is not a problem.
Can anyone point me in the right direction? I'd appreciate it.
[Edit]
Here is the code:
-> Controller factory for Windsor
public WindsorControllerFactory()
{
container = new WindsorContainer(new XmlInterpreter(
new ConfigResource("castle")));
// Register all the controller types as transient
// This is for the regular controllers
var controllerTypes =
from t in
Assembly.GetExecutingAssembly().GetTypes()
where typeof(IController).IsAssignableFrom(t)
select t;
foreach (Type t in controllerTypes)
{
container.AddComponentLifeStyle(t.FullName, t,
LifestyleType.Transient);
}
/* Now the plugin controllers */
foreach (string file in Plugins() )
{
var assy = System.Reflection.Assembly.LoadFile(file);
var pluginContr =
from t in assy.GetTypes()
where typeof(IController).IsAssignableFrom(t)
select t;
foreach (Type t in pluginContr)
{
AddToPlugins(t);
/* This is the only thing I do, with regards to Windsor,
for the plugin Controllers */
container.AddComponentLifeStyle(t.FullName, t,
LifestyleType.Transient);
}
}
}
-> StructureMap; adding the controllers:
public class PluginRegistry : Registry
{
public PluginRegistry()
{
foreach (string file in Plugins() ) // Plugins return string[] of assemblies in the plugin folder
{
var assy = System.Reflection.Assembly.LoadFile(file);
Scan(x =>
{
x.Assembly(assy);
//x.AddAllTypesOf<IController>().
// NameBy(type => type.Name.Replace("Controller", ""));
x.AddAllTypesOf<IController>();
});
}
}
}
-> Controller factory for SM version
Not really doing much, as I'm registering the controllers with SM in the earlier step
public SMControllerFactory()
: base()
{
foreach (string file in Plugins() )
{
var assy = System.Reflection.Assembly.LoadFile(file);
var pluginContr =
from t in assy.GetTypes()
where typeof(IController).IsAssignableFrom(t)
select t;
foreach (Type t in pluginContr)
{
AddPlugin();
}
}
}
Can you post your controller factory?
I don't understand why Castle would work since I would think you would also get null passed in for the Type param of GetControllerInstance regardless of the DI framework you use inside that method. MVC is in charge of matching up the string name of the controller in the URL with a real type (unless you overrode those methods too). So I'm guessing it isn't the DI framework, but that MVC can't find your controller classes for some reason.
Related
I am getting the handle on .NET Core 6 and I am stuck. I am using AutoMapper and I have dependency injection set up.
My implementation:
public class LSif : ISif
{
private readonly DataContext _db;
private readonly IMemoryCache _memoryCache;
public LSif(DataContext db, IMemoryCache memoryCache)
{
_db = db;
_memoryCache = memoryCache;
}
public List<DropDown> MjernaJedinicaDD(int selected)
{
string key = "MjernaJedinicaDD" + selected;
List<DropDown> dd = new List<DropDown>();
if (!_memoryCache.TryGetValue(key, out dd))
{
var model = GetAllMjernaJedinica();
if (model != null)
{
foreach (var item in model)
{
dd.Add(
new DropDown()
{
Id = item.Id,
Name = item.Name,
Selected = selected
}
);
}
}
var cacheEntryOptions = new MemoryCacheEntryOptions()
.SetSlidingExpiration(TimeSpan.FromSeconds(30));
_memoryCache.Set(key, dd, cacheEntryOptions);
}
return dd;
}
}
My goal is to call that implementation method from Automapper resolver:
.ForMember(d => d.MjernaJedinicaDD, o => o.MapFrom<MjernaJedinicaDDArtikal>());
And the resolver looks like this:
public class MjernaJedinicaDDArtikal : IValueResolver<Artikal, ArtikalVM, List<DropDown>>
{
public List<DropDown> Resolve(Artikal source, ArtikalVM destination, List<DropDown> member, ResolutionContext context)
{
var services = new ServiceCollection(); // With this i shoud work
services.AddScoped<ISif, LSif>(); // but i doesn't
using ServiceProvider serviceProvider = services.BuildServiceProvider(validateScopes: true);
using (IServiceScope scope = serviceProvider.CreateScope())
{
ISif reff = scope.ServiceProvider.GetRequiredService<ISif>();
if (reff != null)
{
return reff.MjernaJedinicaDD(source.MjernaId);
}
}
return null;
// This is how I did it in .NET Framework 4.5
var lSif = new LSif();
return lSif.MjernaJedinicaDD(source.MjernaId);
}
}
Question: how to instantiate / access class that has dependency injection components (parameters) form AutoMapper custom resolver?
Aditional info:
I initiate AutoMapper using
public interface IMapFrom<T>
{
void Mapping(Profile profile) => profile.CreateMap(typeof(T), GetType());
}
and then
public class AutoMapperProfile : Profile
{
public AutoMapperProfile()
{
ApplyMappingsFromAssembly(Assembly.GetExecutingAssembly());
}
private void ApplyMappingsFromAssembly(Assembly assembly)
{
var types = assembly.GetExportedTypes()
.Where(t => t.GetInterfaces().Any(i =>
i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IMapFrom<>)))
.ToList();
foreach (var type in types)
{
var instance = Activator.CreateInstance(type);
var methodInfo = type.GetMethod("Mapping") ??
type.GetInterface("IMapFrom`1").GetMethod("Mapping");
methodInfo?.Invoke(instance, new object[] { this });
}
}
}
and finaly in program.cs
builder.Services.AddAutoMapper(Assembly.GetExecutingAssembly());
When you call one of the AddAutoMapper extension methods on IServiceCollection provided by the NuGet package AutoMapper.Extensions.Microsoft.DependencyInjection during startup, this does several things including:
Adding your custom value resolver (e.g. MjernaJedinicaDDArtikal) to the dependency injection (DI) container
Configuring the Mapper to resolve dependencies from the container needed by your custom components that implement AutoMapper interfaces (such as IValueResolver)
(For additional details on what the AddAutoMapper method does, see the README for the NuGet package.)
This allows you to use constructor injection to directly supply the dependencies that your custom value resolver needs. These dependencies will be resolved from the DI container and they can also require other dependencies from the container themselves.
Your custom value resolver becomes:
public class MjernaJedinicaDDArtikal : IValueResolver<Artikal, ArtikalVM, List<DropDown>>
{
private readonly ISif _isif;
public MjernaJedinicaDDArtikal(ISif isif)
{
_isif = isif ?? throw new ArgumentNullException(nameof(isif));
}
public List<DropDown> Resolve(Artikal source, ArtikalVM destination, List<DropDown> member, ResolutionContext context)
{
return _isif.MjernaJedinicaDD(source.MjernaId);
}
}
Here is a simplified version of your AutoMapper profile that uses your custom value resolver:
public class AutoMapperProfile : Profile
{
public AutoMapperProfile()
{
CreateMap<Artikal, ArtikalVM>()
.ForMember(dest => dest.MjernaJedinicaDD, src => src.MapFrom<MjernaJedinicaDDArtikal>());
}
}
Finally, add your ISif service to the container using the LSif class as its implementation as well as any dependencies the LSif class needs.
When using the minimal hosting model for an ASP.NET Core app with .NET 6 or later, add the snippets below to Program.cs (some of the lines included with default .NET templates are included to provide context):
// TODO: add 'using' directives for namespace(s) containing ISif and LSif
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddControllersWithViews(); // or other similar method
// Register DataContext, which is injected into LSif
// TODO: Fill in app-specific implementation
// Register IMemoryCache implementation for injection into LSif
builder.Services.AddMemoryCache(options =>
{
// TODO: fill in desired cache options
});
// Register ISif service using LSif implementation
builder.Services.AddTransient<ISif, LSif>();
builder.Services.AddAutoMapper(Assembly.GetExecutingAssembly());
// ...
var app = builder.Build();
For other people that may want to use a similar approach but are using an earlier version of ASP.NET Core without the minimal hosting model (e.g. ASP.NET Core 3.1 or 5.0 with the Generic Host), add the custom service registrations to Startup.ConfigureServices(IServiceCollection) instead of adding them in Program.cs using builder.Services.AddXyz. For example:
public void ConfigureServices(IServiceCollection services)
{
// ...
// Register DataContext, which is injected into LSif
// TODO: Fill in app-specific implementation
// Register IMemoryCache implementation for injection into LSif
services.AddMemoryCache(options =>
{
// TODO: fill in desired cache options
});
// Register ISif service using LSif implementation
services.AddTransient<ISif, LSif>();
services.AddAutoMapper(Assembly.GetExecutingAssembly());
// ...
}
The way that AutoMapper can use the application's default DI container to resolve dependencies is that the AddAutoMapper extension method passes the IServiceProvider.GetService(Type) method as the serviceCtor argument to the Mapper constructor (source, v11.0.0).
Side note: You may also want to tweak your LSif.MjernaJedinicaDD method to avoid throwing a NullReferenceException on the line for dd.Add(...). After calling _memoryCache.TryGetValue(key, out dd), dd will be null when TryGetValue returns false because null is the default value for any C# reference type, such as a class, which List<T> is (reference).
I have a very simple test in a test project in a solution using ASP MVC V5 and attribute routing. Attribute routing and the MapMvcAttributeRoutes method are part of ASP MVC 5.
[Test]
public void HasRoutesInTable()
{
var routes = new RouteCollection();
routes.MapMvcAttributeRoutes();
Assert.That(routes.Count, Is.GreaterThan(0));
}
This results in:
System.InvalidOperationException :
This method cannot be called during the applications pre-start initialization phase.
Most of the answers to this error message involve configuring membership providers in the web.config file. This project has neither membership providers or a web.config file so the error seems be be occurring for some other reason. How do I move the code out of this "pre-start" state so that the tests can run?
The equivalent code for attributes on ApiController works fine after HttpConfiguration.EnsureInitialized() is called.
I recently upgraded my project to ASP.NET MVC 5 and experienced the exact same issue. When using dotPeek to investigate it, I discovered that there is an internal MapMvcAttributeRoutes extension method that has a IEnumerable<Type> as a parameter which expects a list of controller types. I created a new extension method that uses reflection and allows me to test my attribute-based routes:
public static class RouteCollectionExtensions
{
public static void MapMvcAttributeRoutesForTesting(this RouteCollection routes)
{
var controllers = (from t in typeof(HomeController).Assembly.GetExportedTypes()
where
t != null &&
t.IsPublic &&
t.Name.EndsWith("Controller", StringComparison.OrdinalIgnoreCase) &&
!t.IsAbstract &&
typeof(IController).IsAssignableFrom(t)
select t).ToList();
var mapMvcAttributeRoutesMethod = typeof(RouteCollectionAttributeRoutingExtensions)
.GetMethod(
"MapMvcAttributeRoutes",
BindingFlags.NonPublic | BindingFlags.Static,
null,
new Type[] { typeof(RouteCollection), typeof(IEnumerable<Type>) },
null);
mapMvcAttributeRoutesMethod.Invoke(null, new object[] { routes, controllers });
}
}
And here is how I use it:
public class HomeControllerRouteTests
{
[Fact]
public void RequestTo_Root_ShouldMapTo_HomeIndex()
{
// Arrange
var routes = new RouteCollection();
// Act - registers traditional routes and the new attribute-defined routes
RouteConfig.RegisterRoutes(routes);
routes.MapMvcAttributeRoutesForTesting();
// Assert - uses MvcRouteTester to test specific routes
routes.ShouldMap("~/").To<HomeController>(x => x.Index());
}
}
One problem now is that inside RouteConfig.RegisterRoutes(route) I cannot call routes.MapMvcAttributeRoutes() so I moved that call to my Global.asax file instead.
Another concern is that this solution is potentially fragile since the above method in RouteCollectionAttributeRoutingExtensions is internal and could be removed at any time. A proactive approach would be to check to see if the mapMvcAttributeRoutesMethod variable is null and provide an appropriate error/exceptionmessage if it is.
NOTE: This only works with ASP.NET MVC 5.0. There were significant changes to attribute routing in ASP.NET MVC 5.1 and the mapMvcAttributeRoutesMethod method was moved to an internal class.
In ASP.NET MVC 5.1 this functionality was moved into its own class called AttributeRoutingMapper.
(This is why one shouldn't rely on code hacking around in internal classes)
But this is the workaround for 5.1 (and up?):
public static void MapMvcAttributeRoutes(this RouteCollection routeCollection, Assembly controllerAssembly)
{
var controllerTypes = (from type in controllerAssembly.GetExportedTypes()
where
type != null && type.IsPublic
&& type.Name.EndsWith("Controller", StringComparison.OrdinalIgnoreCase)
&& !type.IsAbstract && typeof(IController).IsAssignableFrom(type)
select type).ToList();
var attributeRoutingAssembly = typeof(RouteCollectionAttributeRoutingExtensions).Assembly;
var attributeRoutingMapperType =
attributeRoutingAssembly.GetType("System.Web.Mvc.Routing.AttributeRoutingMapper");
var mapAttributeRoutesMethod = attributeRoutingMapperType.GetMethod(
"MapAttributeRoutes",
BindingFlags.Public | BindingFlags.Static,
null,
new[] { typeof(RouteCollection), typeof(IEnumerable<Type>) },
null);
mapAttributeRoutesMethod.Invoke(null, new object[] { routeCollection, controllerTypes });
}
Well, it's really ugly and I'm not sure if it'll be worth the test complexity, but here's how you can do it without modifying your RouteConfig.Register code:
[TestClass]
public class MyTestClass
{
[TestMethod]
public void MyTestMethod()
{
// Move all files needed for this test into a subdirectory named bin.
Directory.CreateDirectory("bin");
foreach (var file in Directory.EnumerateFiles("."))
{
File.Copy(file, "bin\\" + file, overwrite: true);
}
// Create a new ASP.NET host for this directory (with all the binaries under the bin subdirectory); get a Remoting proxy to that app domain.
RouteProxy proxy = (RouteProxy)ApplicationHost.CreateApplicationHost(typeof(RouteProxy), "/", Environment.CurrentDirectory);
// Call into the other app domain to run route registration and get back the route count.
int count = proxy.RegisterRoutesAndGetCount();
Assert.IsTrue(count > 0);
}
private class RouteProxy : MarshalByRefObject
{
public int RegisterRoutesAndGetCount()
{
RouteCollection routes = new RouteCollection();
RouteConfig.RegisterRoutes(routes); // or just call routes.MapMvcAttributeRoutes() if that's what you want, though I'm not sure why you'd re-test the framework code.
return routes.Count;
}
}
}
Mapping attribute routes needs to find all the controllers you're using to get their attributes, which requires accessing the build manager, which only apparently works in app domains created for ASP.NET.
What are you testing here? Looks like you are testing a 3rd party extension method. You shouldn't be using your unit tests to test 3rd party code.
I am building a Web API using MVC4 Web API and Simple Injector that should expose a variety of CRUD and query operations. The reason for using IOC in my case is that we are a dev shop and I need to be able to let customers build their own web api controllers to expose the data they need to expose need from our system. Consequently, I was hoping to design my solution in a way that allowed me to dogfood my own product by making all the controllers, both ours and our customers', external and loadable through IOC.
The website does not have any reference to the library but the library contains controllers that I want to use in the website. I have the code finding the dll plugin and loading the controller type but when I try to navigate to the route that it would represent It says it can't find it.
i.e. if I try to navigate to /api/Test1Api I should see the text "hello world"
My problem here is that although I have loaded my controller type, I am unable to translate that into a route that the website says is there.
Here is how I register the container
[assembly: WebActivator.PostApplicationStartMethod(typeof(Spike.Web.Api.App_Start.SimpleInjectorInitializer), "Initialize")]
public static class SimpleInjectorInitializer
{
public static void Initialize()
{
// Create the IOC container.
var container = new Container();
InitializeContainer(container);
container.RegisterMvcAttributeFilterProvider();
// Verify the container configuration
container.Verify();
// Register the dependency resolver.
GlobalConfiguration.Configuration.DependencyResolver =
new SimpleInjectorWebApiDependencyResolver(container);
//DependencyResolver.SetResolver(new SimpleInjectorWebApiDependencyResolver(container));
}
private static void InitializeContainer(Container container)
{
var appPath = AppDomain.CurrentDomain.BaseDirectory;
string[] files = Directory.GetFiles(appPath + "\\bin\\Plugins", "*.dll",
SearchOption.AllDirectories);
var assemblies = files.Select(Assembly.LoadFile);
// register Web API controllers
var apiControllerTypes =
from assembly in assemblies
where !assembly.IsDynamic
from type in assembly.GetExportedTypes()
where typeof(IHttpController).IsAssignableFrom(type)
where !type.IsAbstract
where !type.IsGenericTypeDefinition
where type.Name.EndsWith("Controller", StringComparison.Ordinal)
select type;
// register MVC controllers
var mvcControllerTypes =
from assembly in assemblies
where !assembly.IsDynamic
from type in assembly.GetExportedTypes()
where typeof(IController).IsAssignableFrom(type)
where !type.IsAbstract
where !type.IsGenericTypeDefinition
where type.Name.EndsWith("Controller", StringComparison.Ordinal)
select type;
foreach (var controllerType in apiControllerTypes)
{
container.Register(controllerType);
}
foreach (var controllerType in mvcControllerTypes)
{
container.Register(controllerType);
}
}
}
I figured it out!
So I created a new class in my Web Api call CustomAssembliesResolver that inherits from DefaultAssembliesResolver. Essentially I add my assembly to the list of assemblies that are parsed when looking for controllers. I still have the code that uses Simple Injector for the DI portion of the solution.
public class CustomAssembliesResolver : DefaultAssembliesResolver
{
public override ICollection<Assembly> GetAssemblies()
{
var appPath = AppDomain.CurrentDomain.BaseDirectory;
var baseAssemblies = base.GetAssemblies();
var assemblies = new List<Assembly>(baseAssemblies);
var files = Directory.GetFiles(appPath + "\\bin\\Plugins", "*.dll",
SearchOption.AllDirectories);
var customAssemblies = files.Select(Assembly.LoadFile);
// register Web API controllers
var apiControllerAssemblies =
from assembly in customAssemblies
where !assembly.IsDynamic
from type in assembly.GetExportedTypes()
where typeof(IHttpController).IsAssignableFrom(type)
where !type.IsAbstract
where !type.IsGenericTypeDefinition
where type.Name.EndsWith("Controller", StringComparison.Ordinal)
select assembly;
foreach (var assembly in apiControllerAssemblies)
{
baseAssemblies.Add(assembly);
}
return assemblies;
}
}
I also added the following line to the beginning of the App_Start in the Global.asax.cs
GlobalConfiguration.Configuration.Services.Replace(typeof(IAssembliesResolver), new CustomAssembliesResolver());
Hope this helps someone!
I have this really basic code in a MVC controller action. It maps an Operation model class to a very basic OperationVM view-model class .
public class OperationVM: Operation
{
public CategoryVM CategoryVM { get; set; }
}
I need to load the complete list of categories in order to create a CategoryVM instance.
Here's how I (try to) create a List<OperationVM> to show in the view.
public class OperationsController : Controller {
private SomeContext context = new SomeContext ();
public ViewResult Index()
{
var ops = context.Operations.Include("blah...").ToList();
Mapper.CreateMap<Operation, OperationVM>()
.ForMember(
dest => dest.CategoryVM,
opt => opt.MapFrom(
src => CreateCatVM(src.Category, context.Categories)
// trouble here ----------------^^^^^^^
)
);
var opVMs = ops.Select(op => Mapper.Map<Operation, OperationVM>(op))
.ToList();
return View(opVMs);
}
}
All works great first time I hit the page. The problem is, the mapper object is static. So when calling Mapper.CreateMap(), the instance of the current DbContext is saved in the closure given to CreateMap().
The 2nd time I hit the page, the static map is already in place, still using the reference to the initial, now disposed, DbContext.
The exact error is:
The operation cannot be completed because the DbContext has been disposed.
The question is: How can I make AutoMapper always use the current context instead of the initial one?
Is there a way to use an "instance" of automapper instead of the static Mapper class?
If this is possible, is it recommended to re-create the mapping every time? I'm worried about reflection slow-downs.
I read a bit about custom resolvers, but I get a similar problem - How do I get the custom resolver to use the current context?
It is possible, but the setup is a bit complicated. I use this in my projects with help of Ninject for dependency injection.
AutoMapper has concept of TypeConverters. Converters provide a way to implement complex operations required to convert certain types in a separate class. If converting Category to CategoryVM requires a database lookup you can implement that logic in custom TypeConverter class similar to this:
using System;
using AutoMapper;
public class CategoryToCategoryVMConverter :
TypeConverter<Category, CategoryVM>
{
public CategoryToCategoryVMConverter(DbContext context)
{
this.Context = context;
}
private DbContext Context { get; set; }
protected override CategoryVM ConvertCore(Category source)
{
// use this.Context to lookup whatever you need
return CreateCatVM(source, this.Context.Categories);
}
}
You then to configure AutoMapper to use your converter:
Mapper.CreateMap<Category, CategoryVM>().ConvertUsing<CategoryToCategoryVMConverter>();
Here comes the tricky part. AutoMapper will need to create a new instance of our converter every time you map values, and it will need to provide DbContext instance for constructor. In my projects I use Ninject for dependency injection, and it is configured to use the same instance of DbContext while processing a request. This way the same instance of DbContext is injected both in your controller and in your AutoMapper converter. The trivial Ninject configuration would look like this:
Bind<DbContext>().To<SomeContext>().InRequestScope();
You can of course use some sort of factory pattern to get instance of DbContext instead of injecting it in constructors.
Let me know if you have any questions.
I've found a workaround that's not completely hacky.
Basically, I tell AutoMapper to ignore the tricky field and I update it myself.
The updated controller looks like this:
public class OperationsController : Controller {
private SomeContext context = new SomeContext ();
public ViewResult Index()
{
var ops = context.Operations.Include("blah...").ToList();
Mapper.CreateMap<Operation, OperationVM>()
.ForMember(dest => dest.CategoryVM, opt => opt.Ignore());
var opVMs = ops.Select(
op => {
var opVM = Mapper.Map<Operation, OperationVM>(op);
opVM.CategoryVM = CreateCatVM(op.Category, context.Categories);
return opVM;
})
.ToList();
return View(opVMs);
}
}
Still curious how this could be done from within AutoMapper...
The answer from #LeffeBrune is perfect. However, I want to have the same behavior, but I don't want to map every property myself. Basically I just wanted to override the "ConstructUsing".
Here is what I came up with.
public static class AutoMapperExtension
{
public static void ConstructUsingService<TSource, TDestination>(this IMappingExpression<TSource, TDestination> mappingExression, Type typeConverterType)
{
mappingExression.ConstructUsing((ResolutionContext ctx) =>
{
var constructor = (IConstructorWithService<TSource, TDestination>)ctx.Options.ServiceCtor.Invoke(typeConverterType);
return constructor.Construct((TSource)ctx.SourceValue);
});
}
}
public class CategoryToCategoryVMConstructor : IConstructorWithService<Category, CategoryVM>
{
private DbContext dbContext;
public DTOSiteToHBTISiteConverter(DbContext dbContext)
{
this.dbContext = dbContext;
}
public CategoryVM Construct(Category category)
{
// Some commands here
if (category.Id > 0)
{
var vmCategory = dbContext.Categories.FirstOrDefault(m => m.Id == category.Id);
if (vmCategory == null)
{
throw new NotAllowedException();
}
return vmCategory;
}
return new CategoryVM();
}
}
// Initialization
Mapper.Initialize(cfg =>
{
cfg.ConstructServicesUsing(type => nInjectKernelForInstance.Get(type));
cfg.CreateMap<Category, CategoryVM>().ConstructUsingService(typeof(CategoryToCategoryVMConstructor));
};
Is it possible to get all controllers available to a ControllerFactory?
What I want to do is get a list of all controller types in application, but in a consistent way.
So that all controllers I get are the same ones default request resolution is using.
(The actual task is to find all action methods that have a given attribute).
You can use reflection to enumerate all classes in an assembly, and filter only classes inherit from Controller class.
The best reference is asp.net mvc source code. Take a look of the implementations of ControllerTypeCache and ActionMethodSelector class.
ControllerTypeCache shows how to get all controller classes available.
internal static bool IsControllerType(Type t) {
return
t != null &&
t.IsPublic &&
t.Name.EndsWith("Controller", StringComparison.OrdinalIgnoreCase) &&
!t.IsAbstract &&
typeof(IController).IsAssignableFrom(t);
}
public void EnsureInitialized(IBuildManager buildManager) {
if (_cache == null) {
lock (_lockObj) {
if (_cache == null) {
List<Type> controllerTypes = GetAllControllerTypes(buildManager);
var groupedByName = controllerTypes.GroupBy(
t => t.Name.Substring(0, t.Name.Length - "Controller".Length),
StringComparer.OrdinalIgnoreCase);
_cache = groupedByName.ToDictionary(
g => g.Key,
g => g.ToLookup(t => t.Namespace ?? String.Empty, StringComparer.OrdinalIgnoreCase),
StringComparer.OrdinalIgnoreCase);
}
}
}
}
And ActionMethodSelector shows how to check if a method has desired attribute.
private static List<MethodInfo> RunSelectionFilters(ControllerContext controllerContext, List<MethodInfo> methodInfos) {
// remove all methods which are opting out of this request
// to opt out, at least one attribute defined on the method must return false
List<MethodInfo> matchesWithSelectionAttributes = new List<MethodInfo>();
List<MethodInfo> matchesWithoutSelectionAttributes = new List<MethodInfo>();
foreach (MethodInfo methodInfo in methodInfos) {
ActionMethodSelectorAttribute[] attrs = (ActionMethodSelectorAttribute[])methodInfo.GetCustomAttributes(typeof(ActionMethodSelectorAttribute), true /* inherit */);
if (attrs.Length == 0) {
matchesWithoutSelectionAttributes.Add(methodInfo);
}
else if (attrs.All(attr => attr.IsValidForRequest(controllerContext, methodInfo))) {
matchesWithSelectionAttributes.Add(methodInfo);
}
}
// if a matching action method had a selection attribute, consider it more specific than a matching action method
// without a selection attribute
return (matchesWithSelectionAttributes.Count > 0) ? matchesWithSelectionAttributes : matchesWithoutSelectionAttributes;
}
I don't think it's possible to give a simple answer to this question, because it depends on a lot of different things, including the implementation of IControllerFactory.
For instance, if you have a completely custom-built IControllerFactory implementation, all bets are off, because it may use any sort of mechanism to create Controller instances.
However, the DefaultControllerFactory looks after the appropriate Controller type in all the assemblies defined in the RouteCollection (configured in global.asax).
In this case, you could loop through all the assemblies associated with the RouteCollection, and look for Controllers in each.
Finding Controllers in a given assembly is relatively easy:
var controllerTypes = from t in asm.GetExportedTypes()
where typeof(IController).IsAssignableFrom(t)
select t;
where asm is an Assembly instance.