From e63c46317a54ef55eadd1d3b3a4770d87beb8e44 Mon Sep 17 00:00:00 2001
From: Sipke Schoorstra <sipke@ideliverable.com>
Date: Sat, 5 Jan 2019 14:19:12 +0100
Subject: [PATCH] Simplified DI registration

---
 .../Extensions/ServiceCollectionExtensions.cs |  5 ++-
 .../Extensions/ServiceCollectionExtensions.cs | 17 +++----
 .../Extensions/ServiceCollectionExtensions.cs |  5 ++-
 .../Extensions/ServiceCollectionExtensions.cs |  7 ++-
 .../Extensions/ServiceCollectionExtensions.cs | 45 ++++++++++---------
 .../Extensions/ServiceCollectionExtensions.cs |  3 ++
 src/samples/SampleHost.Web/Startup.cs         | 11 ++---
 .../Elsa.Web.Activities.Console/Startup.cs    |  2 +-
 .../Elsa.Web.Activities.Http/Startup.cs       |  2 +-
 .../Elsa.Web.Activities.Primitives/Startup.cs |  2 +-
 10 files changed, 53 insertions(+), 46 deletions(-)

diff --git a/src/activities/Elsa.Activities.Console/Extensions/ServiceCollectionExtensions.cs b/src/activities/Elsa.Activities.Console/Extensions/ServiceCollectionExtensions.cs
index 54cb5ad21..c81a26035 100644
--- a/src/activities/Elsa.Activities.Console/Extensions/ServiceCollectionExtensions.cs
+++ b/src/activities/Elsa.Activities.Console/Extensions/ServiceCollectionExtensions.cs
@@ -6,14 +6,15 @@ namespace Elsa.Activities.Console.Extensions
 {
     public static class ServiceCollectionExtensions
     {
-        public static IServiceCollection AddConsoleDescriptors(this IServiceCollection services)
+        public static IServiceCollection AddConsoleWorkflowDescriptors(this IServiceCollection services)
         {
             return services.AddActivityDescriptors<ActivityDescriptors>();
         }
         
-        public static IServiceCollection AddConsoleDrivers(this IServiceCollection services)
+        public static IServiceCollection AddConsoleWorkflowDrivers(this IServiceCollection services)
         {
             return services
+                .AddConsoleWorkflowDescriptors()
                 .AddActivityDriver<ReadLineDriver>()
                 .AddActivityDriver<WriteLineDriver>();
         }
diff --git a/src/activities/Elsa.Activities.Http/Extensions/ServiceCollectionExtensions.cs b/src/activities/Elsa.Activities.Http/Extensions/ServiceCollectionExtensions.cs
index 1913eaa9a..e1fa305c5 100644
--- a/src/activities/Elsa.Activities.Http/Extensions/ServiceCollectionExtensions.cs
+++ b/src/activities/Elsa.Activities.Http/Extensions/ServiceCollectionExtensions.cs
@@ -1,3 +1,4 @@
+using AspNetCore.AsyncInitialization;
 using Elsa.Activities.Http.Drivers;
 using Elsa.Activities.Http.Initialization;
 using Elsa.Activities.Http.Services;
@@ -11,19 +12,19 @@ namespace Elsa.Activities.Http.Extensions
 {
     public static class ServiceCollectionExtensions
     {
-        public static IServiceCollection AddHttpDescriptors(this IServiceCollection services)
+        public static IServiceCollection AddHttpWorkflowDescriptors(this IServiceCollection services)
         {
             return services.AddActivityDescriptors<ActivityDescriptors>();
         }
-        
-        public static IServiceCollection AddHttpDrivers(this IServiceCollection services)
-        {
-            services
-                .AddSingleton<IHttpWorkflowCache, DefaultHttpWorkflowCache>()
-                .AddAsyncInitializer<HttpWorkflowCacheInitializer>()
-                .AddActivityDriver<HttpRequestTriggerDriver>();
 
+        public static IServiceCollection AddHttpWorkflowDrivers(this IServiceCollection services)
+        {
+            services.TryAddSingleton<IHttpWorkflowCache, DefaultHttpWorkflowCache>();
+            services.AddAsyncInitialization();
+            services.TryAddTransient<IAsyncInitializer, HttpWorkflowCacheInitializer>();
+            services.AddActivityDriver<HttpRequestTriggerDriver>();
             services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();
+            
             return services;
         }
     }
diff --git a/src/activities/Elsa.Activities.Primitives/Extensions/ServiceCollectionExtensions.cs b/src/activities/Elsa.Activities.Primitives/Extensions/ServiceCollectionExtensions.cs
index 72d76de36..2bc466d32 100644
--- a/src/activities/Elsa.Activities.Primitives/Extensions/ServiceCollectionExtensions.cs
+++ b/src/activities/Elsa.Activities.Primitives/Extensions/ServiceCollectionExtensions.cs
@@ -6,14 +6,15 @@ namespace Elsa.Activities.Primitives.Extensions
 {
     public static class ServiceCollectionExtensions
     {
-        public static IServiceCollection AddPrimitiveDescriptors(this IServiceCollection services)
+        public static IServiceCollection AddPrimitiveWorkflowDescriptors(this IServiceCollection services)
         {
             return services.AddActivityDescriptors<ActivityDescriptors>();
         }
         
-        public static IServiceCollection AddPrimitiveDrivers(this IServiceCollection services)
+        public static IServiceCollection AddPrimitiveWorkflowDrivers(this IServiceCollection services)
         {
             return services
+                .AddPrimitiveWorkflowDescriptors()
                 .AddActivityDriver<SetVariableDriver>()
                 .AddActivityDriver<ForEachDriver>()
                 .AddActivityDriver<IfElseDriver>();
diff --git a/src/core/Elsa.Abstractions/Extensions/ServiceCollectionExtensions.cs b/src/core/Elsa.Abstractions/Extensions/ServiceCollectionExtensions.cs
index 089f2c04c..a83d8a727 100644
--- a/src/core/Elsa.Abstractions/Extensions/ServiceCollectionExtensions.cs
+++ b/src/core/Elsa.Abstractions/Extensions/ServiceCollectionExtensions.cs
@@ -1,4 +1,5 @@
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 
 namespace Elsa.Extensions
 {
@@ -7,13 +8,15 @@ namespace Elsa.Extensions
         public static IServiceCollection AddActivityDescriptors<T>(this IServiceCollection services)
             where T : class, IActivityDescriptorProvider
         {
-            return services.AddSingleton<IActivityDescriptorProvider, T>();
+            services.TryAddSingleton<IActivityDescriptorProvider, T>();
+            return services;
         }
         
         public static IServiceCollection AddActivityDriver<T>(this IServiceCollection services)
             where T : class, IActivityDriver
         {
-            return services.AddSingleton<IActivityDriver, T>();
+            services.TryAddSingleton<IActivityDriver, T>();
+            return services;
         }
     }
 }
\ No newline at end of file
diff --git a/src/core/Elsa.Core/Extensions/ServiceCollectionExtensions.cs b/src/core/Elsa.Core/Extensions/ServiceCollectionExtensions.cs
index a71f87a6b..e35f474f6 100644
--- a/src/core/Elsa.Core/Extensions/ServiceCollectionExtensions.cs
+++ b/src/core/Elsa.Core/Extensions/ServiceCollectionExtensions.cs
@@ -4,6 +4,7 @@ using Elsa.Serialization;
 using Elsa.Serialization.Formatters;
 using Elsa.Serialization.Tokenizers;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 
 namespace Elsa.Extensions
 {
@@ -11,31 +12,33 @@ namespace Elsa.Extensions
     {
         public static IServiceCollection AddWorkflowsCore(this IServiceCollection services)
         {
-            return services
-                .AddSingleton<IIdGenerator, DefaultIdGenerator>()
-                .AddScoped<IWorkflowSerializer, WorkflowSerializer>()
-                .AddScoped<IWorkflowTokenizer, WorkflowTokenizer>()
-                .AddScoped<IActivityHarvester, TypedActivityHarvester>()
-                .AddScoped<IActivityLibrary, ActivityLibrary>()
-                .AddActivityDescriptors<ActivityDescriptors>()
-                .AddSingleton<ITokenFormatter, JsonTokenFormatter>()
-                .AddSingleton<ITokenFormatter, YamlTokenFormatter>()
-                .AddSingleton<ITokenFormatter, XmlTokenFormatter>()
-                .AddSingleton<ITokenFormatterProvider, TokenFormatterProvider>()
-                .AddSingleton<ITokenizerInvoker, TokenizerInvoker>()
-                .AddSingleton<ITokenizer, DefaultTokenizer>()
-                .AddSingleton<ITokenizer, ActivityTokenizer>();
+            services.TryAddSingleton<IIdGenerator, DefaultIdGenerator>();
+            services.TryAddScoped<IWorkflowSerializer, WorkflowSerializer>();
+            services.TryAddScoped<IWorkflowTokenizer, WorkflowTokenizer>();
+            services.TryAddScoped<IActivityHarvester, TypedActivityHarvester>();
+            services.TryAddScoped<IActivityLibrary, ActivityLibrary>();
+            services.AddActivityDescriptors<ActivityDescriptors>();
+            services.TryAddSingleton<ITokenFormatter, JsonTokenFormatter>();
+            services.TryAddSingleton<ITokenFormatter, YamlTokenFormatter>();
+            services.TryAddSingleton<ITokenFormatter, XmlTokenFormatter>();
+            services.TryAddSingleton<ITokenFormatterProvider, TokenFormatterProvider>();
+            services.TryAddSingleton<ITokenizerInvoker, TokenizerInvoker>();
+            services.TryAddSingleton<ITokenizer, DefaultTokenizer>();
+            services.TryAddSingleton<ITokenizer, ActivityTokenizer>();
+
+            return services;
         }
 
         public static IServiceCollection AddWorkflowsInvoker(this IServiceCollection services)
         {
-            return services
-                .AddSingleton<IWorkflowInvoker, WorkflowInvoker>()
-                .AddSingleton<IActivityInvoker, ActivityInvoker>()
-                .AddSingleton<IActivityDriverRegistry, ActivityDriverRegistry>()
-                .AddSingleton<IExpressionEvaluator, PlainTextEvaluator>()
-                .AddSingleton<IExpressionEvaluator, JavaScriptEvaluator>()
-                .AddSingleton<IWorkflowExpressionEvaluator, WorkflowExpressionEvaluator>();
+            services.TryAddSingleton<IWorkflowInvoker, WorkflowInvoker>();
+            services.TryAddSingleton<IActivityInvoker, ActivityInvoker>();
+            services.TryAddSingleton<IActivityDriverRegistry, ActivityDriverRegistry>();
+            services.TryAddSingleton<IExpressionEvaluator, PlainTextEvaluator>();
+            services.TryAddSingleton<IExpressionEvaluator, JavaScriptEvaluator>();
+            services.TryAddSingleton<IWorkflowExpressionEvaluator, WorkflowExpressionEvaluator>();
+
+            return services;
         }
     }
 }
\ No newline at end of file
diff --git a/src/core/Elsa.Runtime/Extensions/ServiceCollectionExtensions.cs b/src/core/Elsa.Runtime/Extensions/ServiceCollectionExtensions.cs
index 1f01f9f45..db9ebcc98 100644
--- a/src/core/Elsa.Runtime/Extensions/ServiceCollectionExtensions.cs
+++ b/src/core/Elsa.Runtime/Extensions/ServiceCollectionExtensions.cs
@@ -1,3 +1,4 @@
+using Elsa.Extensions;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Elsa.Runtime.Extensions
@@ -7,6 +8,8 @@ namespace Elsa.Runtime.Extensions
         public static IServiceCollection AddWorkflowsHost(this IServiceCollection services)
         {
             return services
+                .AddWorkflowsCore()
+                .AddWorkflowsInvoker()
                 .AddScoped<IWorkflowHost, WorkflowHost>();
         }
     }
diff --git a/src/samples/SampleHost.Web/Startup.cs b/src/samples/SampleHost.Web/Startup.cs
index 3f68ff716..0965f59b9 100644
--- a/src/samples/SampleHost.Web/Startup.cs
+++ b/src/samples/SampleHost.Web/Startup.cs
@@ -25,16 +25,11 @@ namespace SampleHost.Web
         {
             services
                 .AddLocalization()
-                .AddWorkflowsCore()
-                .AddWorkflowsInvoker()
                 .AddWorkflowsHost()
                 .AddWorkflowsFileSystemPersistence(Configuration.GetSection("FileStore"))
-                .AddPrimitiveDrivers()
-                .AddPrimitiveDescriptors()
-                .AddConsoleDrivers()
-                .AddConsoleDescriptors()
-                .AddHttpDrivers()
-                .AddHttpDescriptors();
+                .AddPrimitiveWorkflowDrivers()
+                .AddConsoleWorkflowDrivers()
+                .AddHttpWorkflowDrivers();
             
             services
                 .AddMvc()
diff --git a/src/web/modules/Elsa.Web.Activities.Console/Startup.cs b/src/web/modules/Elsa.Web.Activities.Console/Startup.cs
index ec87962fd..543eb4d90 100644
--- a/src/web/modules/Elsa.Web.Activities.Console/Startup.cs
+++ b/src/web/modules/Elsa.Web.Activities.Console/Startup.cs
@@ -11,7 +11,7 @@ namespace Elsa.Web.Activities.Console
         public override void ConfigureServices(IServiceCollection services)
         {
             services
-                .AddConsoleDescriptors()
+                .AddConsoleWorkflowDescriptors()
                 .AddActivityDisplay<ReadLineDisplay>()
                 .AddActivityDisplay<WriteLineDisplay>();
         }
diff --git a/src/web/modules/Elsa.Web.Activities.Http/Startup.cs b/src/web/modules/Elsa.Web.Activities.Http/Startup.cs
index 4f478024e..2d64752d3 100644
--- a/src/web/modules/Elsa.Web.Activities.Http/Startup.cs
+++ b/src/web/modules/Elsa.Web.Activities.Http/Startup.cs
@@ -11,7 +11,7 @@ namespace Elsa.Web.Activities.Http
         public override void ConfigureServices(IServiceCollection services)
         {
             services
-                .AddHttpDescriptors()
+                .AddHttpWorkflowDescriptors()
                 .AddActivityDisplay<HttpRequestTriggerDisplay>();
         }
     }
diff --git a/src/web/modules/Elsa.Web.Activities.Primitives/Startup.cs b/src/web/modules/Elsa.Web.Activities.Primitives/Startup.cs
index ba19d82d9..47f30acee 100644
--- a/src/web/modules/Elsa.Web.Activities.Primitives/Startup.cs
+++ b/src/web/modules/Elsa.Web.Activities.Primitives/Startup.cs
@@ -11,7 +11,7 @@ namespace Elsa.Web.Activities.Primitives
         public override void ConfigureServices(IServiceCollection services)
         {
             services
-                .AddPrimitiveDescriptors()
+                .AddPrimitiveWorkflowDescriptors()
                 .AddActivityDisplay<IfElseDisplay>()
                 .AddActivityDisplay<ForEachDisplay>()
                 .AddActivityDisplay<SetVariableDisplay>()