I have implemented a custom InputFormatter (MyInputFormatter):
public class MyInputFormatter : SystemTextJsonInputFormatter
{
private readonly IMyDepenency _mydependency;
public CustomInputFormatter(
JsonOptions options,
ILogger<SystemTextJsonInputFormatter> logger,
IMyDependency myDependency
) : base(options, logger)
{
_mydependency = myDependency ?? throw new ArgumentNullException(nameof(myDependency));
}
public override async Task<InputFormatterResult> ReadRequestBodyAsync(InputFormatterContext context)
{
//...
}
}
Now, according to the documentation I need to use it as follows:
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers(options =>
{
options.InputFormatters.Insert(0, new MyInputFormatter(...));
});
}
However, as you can see my CustomInputFormatter has some constructor arguments required and needs some services and it's not clear to me how to use DI to resolve these services. I have read through a lot of answers/blogs/pages like this one but either the inputformatter doesn't have any constructor arguments (and so no need for DI, just new up a new instance inline) or the following is suggested:
public void ConfigureServices(IServiceCollection services)
{
var sp = services.BuildServiceProvider();
services.AddControllers(options =>
{
options.InputFormatters.Insert(0, new MyInputFormatter(
sp.GetService<...>(),
sp.GetService<...>(),
sp.GetService<IMyDependency>(),
));
});
}
But we're not supposed to call BuildServiceProvider from ConfigureServices.
How would I go about this?
You can make use of the Options infrastructure and create an IConfigureOptions<MvcOptions> . This new service can take the necessary dependeices. It will be instantiated and "executed" the first time something (the MVC infrastructure) requests an IOptions<MvcOptions>
public class ConfigureMvcOptionsFormatters : IConfigureOptions<MvcOptions>
{
private readonly ILoggerFactory _factory;
private readonly JsonOptions _jsonOpts;
private readonly IMyDependency _depend;
public ConfigureMvcOptionsFormatters(IOptions<JsonOptions> options, ILoggerFactory loggerFactory, IMyDependency myDependency)
{
_factory = loggerFactory;
_jsonOpts = options.Value;
_depend = myDependency;
}
public void Configure(MvcOptions options)
{
var logger = _factory.CreateLogger<SystemTextJsonInputFormatter>();
var formatter = new MyInputFormatter(_jsonOpts, logger, _depend);
options.InputFormatters.Insert(0, formatter);
}
}
You then register your class to have its IConfigureOptions implementation run by calling the ConfigureOptions<T>() extension method on the IServiceCollection:
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
services.ConfigureOptions<ConfigureMvcOptionsFormatters>();
}
Alternatively you can use an Options builder along with Configure and it's callback, specifying your dependencies as the generic arguments.
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
services.AddOptions<MvcOptions>()
.Configure<IOptions<JsonOptions>, ILoggerFactory, IMyDependency>(
(o, j, l, d) => o.InputFormatters.Insert(0, new MyInputFormatter(j.Value, l.CreateLogger<SystemTextJsonInputFormatter>(), d)
);
}
Note: I've been using ILoggerFactory because I don't believe the infrastructure will inject an ILogger<ClassA> into ClassB. However, I admit I've never tried it and I'm not near a computer to verify. If it is in fact allowed, you can specify the type you need directly instead.
Related
I need to access current HttpContext in a static method or a utility service.
With classic ASP.NET MVC and System.Web, I would just use HttpContext.Current to access the context statically. But how do I do this in ASP.NET Core?
HttpContext.Current doesn't exist anymore in ASP.NET Core but there's a new IHttpContextAccessor that you can inject in your dependencies and use to retrieve the current HttpContext:
public class MyComponent : IMyComponent
{
private readonly IHttpContextAccessor _contextAccessor;
public MyComponent(IHttpContextAccessor contextAccessor)
{
_contextAccessor = contextAccessor;
}
public string GetDataFromSession()
{
return _contextAccessor.HttpContext.Session.GetString(*KEY*);
}
}
Necromancing.
YES YOU CAN
Secret tip for those migrating large junks chunks (sigh, Freudian slip) of code.
The following method is an evil carbuncle of a hack which is actively engaged in carrying out the express work of satan (in the eyes of .NET Core framework developers), but it works:
In public class Startup
add a property
public IConfigurationRoot Configuration { get; }
And then add a singleton IHttpContextAccessor to DI in ConfigureServices.
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();
Then in Configure
public void Configure(
IApplicationBuilder app
,IHostingEnvironment env
,ILoggerFactory loggerFactory
)
{
add the DI Parameter IServiceProvider svp, so the method looks like:
public void Configure(
IApplicationBuilder app
,IHostingEnvironment env
,ILoggerFactory loggerFactory
,IServiceProvider svp)
{
Next, create a replacement class for System.Web:
namespace System.Web
{
namespace Hosting
{
public static class HostingEnvironment
{
public static bool m_IsHosted;
static HostingEnvironment()
{
m_IsHosted = false;
}
public static bool IsHosted
{
get
{
return m_IsHosted;
}
}
}
}
public static class HttpContext
{
public static IServiceProvider ServiceProvider;
static HttpContext()
{ }
public static Microsoft.AspNetCore.Http.HttpContext Current
{
get
{
// var factory2 = ServiceProvider.GetService<Microsoft.AspNetCore.Http.IHttpContextAccessor>();
object factory = ServiceProvider.GetService(typeof(Microsoft.AspNetCore.Http.IHttpContextAccessor));
// Microsoft.AspNetCore.Http.HttpContextAccessor fac =(Microsoft.AspNetCore.Http.HttpContextAccessor)factory;
Microsoft.AspNetCore.Http.HttpContext context = ((Microsoft.AspNetCore.Http.HttpContextAccessor)factory).HttpContext;
// context.Response.WriteAsync("Test");
return context;
}
}
} // End Class HttpContext
}
Now in Configure, where you added the IServiceProvider svp, save this service provider into the static variable "ServiceProvider" in the just created dummy class System.Web.HttpContext (System.Web.HttpContext.ServiceProvider)
and set HostingEnvironment.IsHosted to true
System.Web.Hosting.HostingEnvironment.m_IsHosted = true;
this is essentially what System.Web did, just that you never saw it (I guess the variable was declared as internal instead of public).
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
ServiceProvider = svp;
System.Web.HttpContext.ServiceProvider = svp;
System.Web.Hosting.HostingEnvironment.m_IsHosted = true;
app.UseCookieAuthentication(new CookieAuthenticationOptions()
{
AuthenticationScheme = "MyCookieMiddlewareInstance",
LoginPath = new Microsoft.AspNetCore.Http.PathString("/Account/Unauthorized/"),
AccessDeniedPath = new Microsoft.AspNetCore.Http.PathString("/Account/Forbidden/"),
AutomaticAuthenticate = true,
AutomaticChallenge = true,
CookieSecure = Microsoft.AspNetCore.Http.CookieSecurePolicy.SameAsRequest
, CookieHttpOnly=false
});
Like in ASP.NET Web-Forms, you'll get a NullReference when you're trying to access a HttpContext when there is none, such as it used to be in Application_Start in global.asax.
I stress again, this only works if you actually added
services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();
like I wrote you should.
Welcome to the ServiceLocator pattern within the DI pattern ;)
For risks and side effects, ask your resident doctor or pharmacist - or study the sources of .NET Core at github.com/aspnet, and do some testing.
Perhaps a more maintainable method would be adding this helper class
namespace System.Web
{
public static class HttpContext
{
private static Microsoft.AspNetCore.Http.IHttpContextAccessor m_httpContextAccessor;
public static void Configure(Microsoft.AspNetCore.Http.IHttpContextAccessor httpContextAccessor)
{
m_httpContextAccessor = httpContextAccessor;
}
public static Microsoft.AspNetCore.Http.HttpContext Current
{
get
{
return m_httpContextAccessor.HttpContext;
}
}
}
}
And then calling HttpContext.Configure in Startup->Configure
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
System.Web.HttpContext.Configure(app.ApplicationServices.
GetRequiredService<Microsoft.AspNetCore.Http.IHttpContextAccessor>()
);
The most legit way I came up with was by injecting IHttpContextAccessor in your static implementation as follow:
public static class HttpHelper
{
private static IHttpContextAccessor _accessor;
public static void Configure(IHttpContextAccessor httpContextAccessor)
{
_accessor = httpContextAccessor;
}
public static HttpContext HttpContext => _accessor.HttpContext;
}
Then assigning the IHttpContextAccessor in the Startup Configure should do the job.
HttpHelper.Configure(app.ApplicationServices.GetRequiredService<IHttpContextAccessor>());
I guess you should also need to register the service singleton:
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
Just to add to the other answers...
In ASP.NET Core 2.1, there's the AddHttpContextAccessor extension method, that will register the IHttpContextAccessor with the correct lifetime:
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddHttpContextAccessor();
// Other code...
}
}
According to this article: Accessing HttpContext outside of framework components in ASP.NET Core
namespace System.Web
{
public static class HttpContext
{
private static IHttpContextAccessor _contextAccessor;
public static Microsoft.AspNetCore.Http.HttpContext Current => _contextAccessor.HttpContext;
internal static void Configure(IHttpContextAccessor contextAccessor)
{
_contextAccessor = contextAccessor;
}
}
}
Then:
public static class StaticHttpContextExtensions
{
public static void AddHttpContextAccessor(this IServiceCollection services)
{
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}
public static IApplicationBuilder UseStaticHttpContext(this IApplicationBuilder app)
{
var httpContextAccessor = app.ApplicationServices.GetRequiredService<IHttpContextAccessor>();
System.Web.HttpContext.Configure(httpContextAccessor);
return app;
}
}
Then:
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddHttpContextAccessor();
}
public void Configure(IApplicationBuilder app)
{
app.UseStaticHttpContext();
app.UseMvc();
}
}
You can use it like this:
using System.Web;
public class MyService
{
public void DoWork()
{
var context = HttpContext.Current;
// continue with context instance
}
}
In Startup
services.AddHttpContextAccessor();
In Controller
public class HomeController : Controller
{
private readonly IHttpContextAccessor _context;
public HomeController(IHttpContextAccessor context)
{
_context = context;
}
public IActionResult Index()
{
var context = _context.HttpContext.Request.Headers.ToList();
return View();
}
}
To access to the session object from a class without explicitly use dependency injection in class constructor follow the next steps:
Add a Singleton instance on Startup.cs (ConfigureServices):
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
In your target class declare an instance of HttpContextAccessor:
IHttpContextAccessor _httpContextAccessor = new HttpContextAccessor();
Access to the session object :
string mySessionVar = _httpContextAccessor.HttpContext.Session.GetString("_MySessionVar");
EXAMPLE
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}
YourClass.cs
public class YourClass {
public string yourProperty {
get{
IHttpContextAccessor _httpContextAccessor = new HttpContextAccessor();
return _httpContextAccessor.HttpContext.Session.GetString("_YourSessionVar");
}
}
}
Enjoy :)
I have an ASP.Net Core 2.1 application. I need to register & inject few dependencies of AWS.
Currently, the implementation looks like this:
public abstract class BaseService
{
protected readonly IConfiguration _configuration;
protected readonly RegionEndpoint _region;
protected readonly IAmazonDynamoDB _dynamoClient;
protected IPocoDynamo _pocoDynamo;
public BaseService(IConfiguration configuration)
{
_configuration = configuration;
var awsSettings = configuration.GetSection("AWS");
_dynamoClient = SetDynamoClient(awsSettings);
_pocoDynamo = SetPocoDynamoClient();
}
protected IAmazonDynamoDB SetDynamoClient(IConfigurationSection configuration)
{
AWSCredentials credentials = new BasicAWSCredentials(configuration["AccessKey"], configuration["AccessSecret"]);
return new AmazonDynamoDBClient(credentials, _region);
}
protected IPocoDynamo SetPocoDynamoClient()
{
return new PocoDynamo(_dynamoClient);
}
}
While unit testing, AWS services can't be mocked due to this.
I want to register all these dependencies in Startup.cs in ConfigureServices()
This is what I was trying:
public void ConfigureServices(IServiceCollection services)
{
AWSCredentials credentials = new BasicAWSCredentials(configuration["AccessKey"], configuration["AccessSecret"]);
services.AddTransient(IAmazonDynamoDB, (a) =>
{
return new AmazonDynamoDBClient(credentials, RegionEndpoint.GetBySystemName(""))
});
// here I need to pass the IAmazonDynamoDB to below IOC
// services.AddSingleton<IPocoDynamo,new PocoDynamo()> ();
return services;
}
But this is throwing an error
Error CS0119 'IAmazonDynamoDB' is a type, which is not valid in the given context
How to configure dependencies as required here?
Thanks!
Use factory delegate to call the registered service
public void ConfigureServices(IServiceCollection services) {
AWSCredentials credentials = new BasicAWSCredentials(configuration["AccessKey"], configuration["AccessSecret"]);
services.AddTransient<IAmazonDynamoDB>(sp =>
new AmazonDynamoDBClient(credentials, RegionEndpoint.GetBySystemName(""))
);
//here pass the IAmazonDynamoDB to below IOC
services.AddSingleton<IPocoDynamo>(serviceProvider => {
var pocoDynamo = new PocoDynamo(serviceProvider.GetRequieredService<IAmazonDynamoDB>());
pocoDynamo.SomeMethod();
return pocoDynamo;
});
}
The target class should no longer need to be dependent on IConfiguration as the dependencies can be explicitly injected via constructor injection.
public abstract class BaseService {
protected readonly IAmazonDynamoDB dynamoClient;
protected readonly IPocoDynamo pocoDynamo;
public BaseService(IAmazonDynamoDB dynamoClient, IPocoDynamo pocoDynamo) {
this.dynamoClient = dynamoClient;
this.pocoDynamo = pocoDynamo;
}
}
I need to access current HttpContext in a static method or a utility service.
With classic ASP.NET MVC and System.Web, I would just use HttpContext.Current to access the context statically. But how do I do this in ASP.NET Core?
HttpContext.Current doesn't exist anymore in ASP.NET Core but there's a new IHttpContextAccessor that you can inject in your dependencies and use to retrieve the current HttpContext:
public class MyComponent : IMyComponent
{
private readonly IHttpContextAccessor _contextAccessor;
public MyComponent(IHttpContextAccessor contextAccessor)
{
_contextAccessor = contextAccessor;
}
public string GetDataFromSession()
{
return _contextAccessor.HttpContext.Session.GetString(*KEY*);
}
}
Necromancing.
YES YOU CAN
Secret tip for those migrating large junks chunks (sigh, Freudian slip) of code.
The following method is an evil carbuncle of a hack which is actively engaged in carrying out the express work of satan (in the eyes of .NET Core framework developers), but it works:
In public class Startup
add a property
public IConfigurationRoot Configuration { get; }
And then add a singleton IHttpContextAccessor to DI in ConfigureServices.
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();
Then in Configure
public void Configure(
IApplicationBuilder app
,IHostingEnvironment env
,ILoggerFactory loggerFactory
)
{
add the DI Parameter IServiceProvider svp, so the method looks like:
public void Configure(
IApplicationBuilder app
,IHostingEnvironment env
,ILoggerFactory loggerFactory
,IServiceProvider svp)
{
Next, create a replacement class for System.Web:
namespace System.Web
{
namespace Hosting
{
public static class HostingEnvironment
{
public static bool m_IsHosted;
static HostingEnvironment()
{
m_IsHosted = false;
}
public static bool IsHosted
{
get
{
return m_IsHosted;
}
}
}
}
public static class HttpContext
{
public static IServiceProvider ServiceProvider;
static HttpContext()
{ }
public static Microsoft.AspNetCore.Http.HttpContext Current
{
get
{
// var factory2 = ServiceProvider.GetService<Microsoft.AspNetCore.Http.IHttpContextAccessor>();
object factory = ServiceProvider.GetService(typeof(Microsoft.AspNetCore.Http.IHttpContextAccessor));
// Microsoft.AspNetCore.Http.HttpContextAccessor fac =(Microsoft.AspNetCore.Http.HttpContextAccessor)factory;
Microsoft.AspNetCore.Http.HttpContext context = ((Microsoft.AspNetCore.Http.HttpContextAccessor)factory).HttpContext;
// context.Response.WriteAsync("Test");
return context;
}
}
} // End Class HttpContext
}
Now in Configure, where you added the IServiceProvider svp, save this service provider into the static variable "ServiceProvider" in the just created dummy class System.Web.HttpContext (System.Web.HttpContext.ServiceProvider)
and set HostingEnvironment.IsHosted to true
System.Web.Hosting.HostingEnvironment.m_IsHosted = true;
this is essentially what System.Web did, just that you never saw it (I guess the variable was declared as internal instead of public).
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
ServiceProvider = svp;
System.Web.HttpContext.ServiceProvider = svp;
System.Web.Hosting.HostingEnvironment.m_IsHosted = true;
app.UseCookieAuthentication(new CookieAuthenticationOptions()
{
AuthenticationScheme = "MyCookieMiddlewareInstance",
LoginPath = new Microsoft.AspNetCore.Http.PathString("/Account/Unauthorized/"),
AccessDeniedPath = new Microsoft.AspNetCore.Http.PathString("/Account/Forbidden/"),
AutomaticAuthenticate = true,
AutomaticChallenge = true,
CookieSecure = Microsoft.AspNetCore.Http.CookieSecurePolicy.SameAsRequest
, CookieHttpOnly=false
});
Like in ASP.NET Web-Forms, you'll get a NullReference when you're trying to access a HttpContext when there is none, such as it used to be in Application_Start in global.asax.
I stress again, this only works if you actually added
services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();
like I wrote you should.
Welcome to the ServiceLocator pattern within the DI pattern ;)
For risks and side effects, ask your resident doctor or pharmacist - or study the sources of .NET Core at github.com/aspnet, and do some testing.
Perhaps a more maintainable method would be adding this helper class
namespace System.Web
{
public static class HttpContext
{
private static Microsoft.AspNetCore.Http.IHttpContextAccessor m_httpContextAccessor;
public static void Configure(Microsoft.AspNetCore.Http.IHttpContextAccessor httpContextAccessor)
{
m_httpContextAccessor = httpContextAccessor;
}
public static Microsoft.AspNetCore.Http.HttpContext Current
{
get
{
return m_httpContextAccessor.HttpContext;
}
}
}
}
And then calling HttpContext.Configure in Startup->Configure
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
System.Web.HttpContext.Configure(app.ApplicationServices.
GetRequiredService<Microsoft.AspNetCore.Http.IHttpContextAccessor>()
);
The most legit way I came up with was by injecting IHttpContextAccessor in your static implementation as follow:
public static class HttpHelper
{
private static IHttpContextAccessor _accessor;
public static void Configure(IHttpContextAccessor httpContextAccessor)
{
_accessor = httpContextAccessor;
}
public static HttpContext HttpContext => _accessor.HttpContext;
}
Then assigning the IHttpContextAccessor in the Startup Configure should do the job.
HttpHelper.Configure(app.ApplicationServices.GetRequiredService<IHttpContextAccessor>());
I guess you should also need to register the service singleton:
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
Just to add to the other answers...
In ASP.NET Core 2.1, there's the AddHttpContextAccessor extension method, that will register the IHttpContextAccessor with the correct lifetime:
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddHttpContextAccessor();
// Other code...
}
}
According to this article: Accessing HttpContext outside of framework components in ASP.NET Core
namespace System.Web
{
public static class HttpContext
{
private static IHttpContextAccessor _contextAccessor;
public static Microsoft.AspNetCore.Http.HttpContext Current => _contextAccessor.HttpContext;
internal static void Configure(IHttpContextAccessor contextAccessor)
{
_contextAccessor = contextAccessor;
}
}
}
Then:
public static class StaticHttpContextExtensions
{
public static void AddHttpContextAccessor(this IServiceCollection services)
{
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}
public static IApplicationBuilder UseStaticHttpContext(this IApplicationBuilder app)
{
var httpContextAccessor = app.ApplicationServices.GetRequiredService<IHttpContextAccessor>();
System.Web.HttpContext.Configure(httpContextAccessor);
return app;
}
}
Then:
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddHttpContextAccessor();
}
public void Configure(IApplicationBuilder app)
{
app.UseStaticHttpContext();
app.UseMvc();
}
}
You can use it like this:
using System.Web;
public class MyService
{
public void DoWork()
{
var context = HttpContext.Current;
// continue with context instance
}
}
In Startup
services.AddHttpContextAccessor();
In Controller
public class HomeController : Controller
{
private readonly IHttpContextAccessor _context;
public HomeController(IHttpContextAccessor context)
{
_context = context;
}
public IActionResult Index()
{
var context = _context.HttpContext.Request.Headers.ToList();
return View();
}
}
To access to the session object from a class without explicitly use dependency injection in class constructor follow the next steps:
Add a Singleton instance on Startup.cs (ConfigureServices):
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
In your target class declare an instance of HttpContextAccessor:
IHttpContextAccessor _httpContextAccessor = new HttpContextAccessor();
Access to the session object :
string mySessionVar = _httpContextAccessor.HttpContext.Session.GetString("_MySessionVar");
EXAMPLE
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}
YourClass.cs
public class YourClass {
public string yourProperty {
get{
IHttpContextAccessor _httpContextAccessor = new HttpContextAccessor();
return _httpContextAccessor.HttpContext.Session.GetString("_YourSessionVar");
}
}
}
Enjoy :)
In one of our app I am already using the dependency injection of AppTenant class like follows
public void ConfigureServices(IServiceCollection services)
{
services.AddMultitenancy<AppTenant, CachingAppTenantResolver>();
services.Configure<MultitenancyOptions>(Configuration.GetSection("Multitenancy"));
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
app.UseMultitenancy<AppTenant>();
}
and in controller i am able to access it easily as follows
public AccountController(AppTenant tenant)
{
this.tenant = tenant;
}
Now, I want to access the same AppTenant OR HttpContext in other project class in the same solution.
So, I have tried like this
public SqlStringLocalizerFactory(
AppTenant tenant)
{
_tenant = tenant;
}
But it is coming null, so what I need to do, to get the AppTenant OR HttpContext in the other project class ?
For SqlStringLocalizerFactory class the services are written in ConfigureServices method like follows
public static class SqlLocalizationServiceCollectionExtensions
{
public static IServiceCollection AddSqlLocalization(this IServiceCollection services)
{
if (services == null)
{
throw new ArgumentNullException(nameof(services));
}
return AddSqlLocalization(services, setupAction: null);
}
public static IServiceCollection AddSqlLocalization(
this IServiceCollection services,
Action<SqlLocalizationOptions> setupAction)
{
if (services == null)
{
throw new ArgumentNullException(nameof(services));
}
services.TryAdd(new ServiceDescriptor(
typeof(IStringExtendedLocalizerFactory),
typeof(SqlStringLocalizerFactory),
ServiceLifetime.Singleton));
services.TryAdd(new ServiceDescriptor(
typeof(IStringLocalizerFactory),
typeof(SqlStringLocalizerFactory),
ServiceLifetime.Singleton));
services.TryAdd(new ServiceDescriptor(
typeof(IStringLocalizer),
typeof(SqlStringLocalizer),
ServiceLifetime.Singleton));
if (setupAction != null)
{
services.Configure(setupAction);
}
return services;
}
}
I have even tried with IHttpContextAccessor, but still not getting any success.
Any help on this appreciated !
Edit-2
New Solution:
public SqlStringLocalizerFactory(IHttpContextAccessor _accessor)
{
_accessor= accessor;
}
public void SomeMethod()
{
var tenant = _accessor.HttpContext.RequestServices
.GetRequiredService<AppTenant>();
}
Edit : IServiceProvider way doesn't work as i expect. See #Sock's solution
First, i assumes the problem occurs because of captive dependency as pointed by #qujck. To avoid captive dependency:
If lifetime of SqlStringLocalizerFactory must be singleton(some cases must be), in this
case use IServiceProvider:
public SqlStringLocalizerFactory(IServiceProvider serviceProvider)
{
_serviceProvider = serviceProvider;
}
public void SomeMethod()
{
var tenant = _serviceProvider.GetService<AppTenant>();
}
Otherwise using AddScoped seems reasonable for your case.
You have two options, the best option, if the SqlStringLocalizerFactory can be a scoped dependency (you get a new instance for every request) then you can register it as a scoped dependency:
services.TryAdd(new ServiceDescriptor(
typeof(IStringLocalizerFactory),
typeof(SqlStringLocalizerFactory),
ServiceLifetime.Scoped));
If the SqlStringLocalizerFactory must be a a Singleton dependency, then you need to make sure you resolve a scoped dependency for the Tenant by using a ServiceSope:
public class SqlStringLocalizerFactory
{
private readonly IServiceProvider _serviceProvider;
public SqlStringLocalizerFactory(IServiceProvider serviceProvider)
{
_serviceProvider = serviceProvider;
}
public void SomeMethod()
{
using (var serviceScope = _serviceProvider
.GetRequiredService<IServiceScopeFactory>().CreateScope())
{
var tenant = serviceScope.ServiceProvider.GetService<AppTenant>();
// do something with tenant...
}
}
}
I'm currently trying to write an AuthenticationMiddleware. See this answer. The app builds with no error but when I execute dnx web I get the following error:
Unable to locate suitable constructor for type 'Namespace.BasicAuthenticationMiddleware'. Ensure the type is concrete and all parameters are accepted by a constructor.
at Microsoft.Extensions.Internal.ActivatorUtilities.CreateInstance(IServiceProvider
provider, Type instanceType, Object[] parameters)
at Microsoft.AspNet.Builder.UseMiddlewareExtensions.<>c__DisplayClass2_0.b__0(RequestDelegate next)
at Microsoft.AspNet.Builder.Internal.ApplicationBuilder.Build()
at Microsoft.AspNet.Hosting.Internal.HostingEngine.BuildApplication()
fail: Microsoft.AspNet.Hosting.Internal.HostingEngine[7]
I'm sure that the Constructor signature I use is wrong in some way but I'm not able to find a suitable documentation for this, since it seems like there are dozens of deprecated ones.
This is the AuthenticationMiddleware:
public class BasicAuthenticationMiddleware : AuthenticationMiddleware<BasicAuthOptions>
{
public BasicAuthenticationMiddleware(
RequestDelegate next,
BasicAuthOptions options,
ILoggerFactory loggerFactory,
IUrlEncoder urlEncoder)
: base(next, options, loggerFactory, urlEncoder) {}
protected override AuthenticationHandler<BasicAuthOptions> CreateHandler()
{
return new BasicAuthenticationHandler();
}
}
BasicAuthOptions:
public class BasicAuthOptions : AuthenticationOptions {
public const string Scheme = "BasicAuth";
public BasicAuthOptions()
{
AuthenticationScheme = Scheme;
AutomaticAuthenticate = true;
}
}
BasicAuthenticationExtensions
public static class BasicAuthenticationExtensions
{
public static void UseBasicAuthentication(this IApplicationBuilder builder) {
builder.UseMiddleware<BasicAuthenticationMiddleware>(new ConfigureOptions<BasicAuthOptions>(o => new BasicAuthOptions()));
}
}
Startup.cs:
public class Startup
{
public Startup(IHostingEnvironment env)
{
// Set up configuration sources.
var builder = new ConfigurationBuilder()
.AddJsonFile("appsettings.json")
.AddEnvironmentVariables();
Configuration = builder.Build();
}
public IConfigurationRoot Configuration { get; set; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
// Add framework services.
services.AddMvc();
services.AddAuthorization(options => {
options.AddPolicy(BasicAuthOptions.Scheme, policy => policy.Requirements.Add(new BasicAuthRequirement()));
});
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
app.UseIISPlatformHandler();
app.UseStaticFiles();
app.UseBasicAuthentication();
app.UseMvc();
}
// Entry point for the application.
public static void Main(string[] args) => Microsoft.AspNet.Hosting.WebApplication.Run<Startup>(args);
}
Your UseBasicAuthentication extension tries to inject a ConfigureOptions instance that your middleware doesn't take as a parameter.
Simply flow the options instance as-is:
public static class BasicAuthenticationExtensions {
public static void UseBasicAuthentication(this IApplicationBuilder builder) {
builder.UseMiddleware<BasicAuthenticationMiddleware>(new BasicAuthOptions());
}
}