Fix handling of per-request singletons in ASP.NET Core

Author: Daniel15

src/React.AspNet/HttpContextLifetimeProvider.cs

@@ -22,15 +22,22 @@ namespace React.AspNet
 	/// </summary>
 	internal class HttpContextLifetimeProvider : TinyIoCContainer.ITinyIoCObjectLifetimeProvider
 	{
-		private readonly IServiceProvider _appServiceProvider;
+		private readonly IHttpContextAccessor _httpContextAccessor;
 
 		/// <summary>
 		/// Creates a new <see cref="HttpContextLifetimeProvider" />.
 		/// </summary>
-		/// <param name="appServiceProvider">ASP.NET dependency injection service provider</param>
-		public HttpContextLifetimeProvider(IServiceProvider appServiceProvider)
+		public HttpContextLifetimeProvider(IHttpContextAccessor httpContextAccessor)
 		{
-			_appServiceProvider = appServiceProvider;
+			if (httpContextAccessor == null)
+			{
+				throw new ReactNotInitialisedException(
+					"IHttpContextAccessor is not registered correctly. Please add it to your " +
+					"application startup:\n" +
+					"services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();"
+				);
+			}
+			_httpContextAccessor = httpContextAccessor;
 		}
 
 		/// <summary>
@@ -50,7 +57,8 @@ private PerRequestRegistrations Registrations
 		{
 			get
 			{
-				var registrations = _appServiceProvider.GetService<PerRequestRegistrations>();
+				var requestServices = _httpContextAccessor.HttpContext.RequestServices;
+				var registrations = requestServices.GetService<PerRequestRegistrations>();
 				if (registrations == null)
 				{
 					throw new ReactNotInitialisedException(

src/React.AspNet/ReactBuilderExtensions.cs

@@ -10,6 +10,7 @@
 using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.PlatformAbstractions;
 using React.Exceptions;
 using React.TinyIoC;
@@ -39,7 +40,10 @@ public static IApplicationBuilder UseReact(
 
 			React.AssemblyRegistration.Container.Register(app.ApplicationServices.GetRequiredService<IHostingEnvironment>());
 
-			Initializer.Initialize(registerOptions => AsPerRequestSingleton(app.ApplicationServices, registerOptions));
+			Initializer.Initialize(registerOptions => AsPerRequestSingleton(
+				app.ApplicationServices.GetService<IHttpContextAccessor>(), 
+				registerOptions
+			));
 			configure(ReactSiteConfiguration.Configuration);
 
 			// Allow serving of .jsx files
@@ -55,13 +59,13 @@ public static IApplicationBuilder UseReact(
 		/// <param name="registerOptions">Registration options</param>
 		/// <returns>Registration options (for chaining)</returns>
 		private static TinyIoCContainer.RegisterOptions AsPerRequestSingleton(
-			IServiceProvider appServiceProvider,
+			IHttpContextAccessor httpContextAccessor,
 			TinyIoCContainer.RegisterOptions registerOptions
 		)
 		{
 			return TinyIoCContainer.RegisterOptions.ToCustomLifetimeManager(
 				registerOptions,
-				new HttpContextLifetimeProvider(appServiceProvider),
+				new HttpContextLifetimeProvider(httpContextAccessor),
 				"per request singleton"
 			);
 		}

src/React.Sample.Mvc6/Startup.cs

@@ -9,6 +9,7 @@
 
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -34,6 +35,8 @@ public void ConfigureServices(IServiceCollection services)
 			// Add MVC services to the services container.
 			services.AddMvc();
 
+			services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
+
 			// Add ReactJS.NET services.
 			services.AddReact();
 		}