Enable adding api controllers

src/Umbraco.Core/Composing/TypeCollectionBuilderBase.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+
+namespace Umbraco.Core.Composing
+{
+    /// <summary>
+    /// Provides a base class for collections of types.
+    /// </summary>
+    public abstract class TypeCollectionBuilderBase<TCollection, TConstraint> : ICollectionBuilder<TCollection, Type>
+        where TCollection : class, IBuilderCollection<Type>
+    {
+        private readonly HashSet<Type> _types = new HashSet<Type>();
+
+        private Type Validate(Type type, string action)
+        {
+            if (!typeof(TConstraint).IsAssignableFrom(type))
+                throw new InvalidOperationException($"Cannot {action} type {type.FullName} as it does not inherit from/implement {typeof(TConstraint).FullName}.");
+            return type;
+        }
+
+        public void Add(Type type) => _types.Add(Validate(type, "add"));
+
+        public void Add<T>() => Add(typeof(T));
+
+        public void Add(IEnumerable<Type> types)
+        {
+            foreach (var type in types) Add(type);
+        }
+
+        public void Remove(Type type) => _types.Remove(Validate(type, "remove"));
+
+        public void Remove<T>() => Remove(typeof(T));
+
+        public TCollection CreateCollection(IFactory factory)
+        {
+            return factory.CreateInstance<TCollection>(_types);
+        }
+
+        public void RegisterWith(IRegister register)
+        {
+            register.Register(CreateCollection, Lifetime.Singleton);
+        }
+    }
+}

src/Umbraco.Core/Umbraco.Core.csproj

@@ -214,6 +214,7 @@
     <Compile Include="Migrations\Upgrade\V_8_0_0\RenameLabelAndRichTextPropertyEditorAliases.cs" />
     <Compile Include="PublishedModelFactoryExtensions.cs" />
     <Compile Include="Services\PropertyValidationService.cs" />
+    <Compile Include="Composing\TypeCollectionBuilderBase.cs" />
     <Compile Include="TypeLoaderExtensions.cs" />
     <Compile Include="Composing\WeightAttribute.cs" />
     <Compile Include="Composing\WeightedCollectionBuilderBase.cs" />

src/Umbraco.Web/Mvc/SurfaceControllerTypeCollection.cs

@@ -4,10 +4,6 @@ using Umbraco.Core.Composing;
 
 namespace Umbraco.Web.Mvc
 {
-    // unless we want to modify the content of the collection
-    // which we are not doing at the moment
-    // we can inherit from BuilderCollectionBase and just be enumerable
-    
     public class SurfaceControllerTypeCollection : BuilderCollectionBase<Type>
     {
         public SurfaceControllerTypeCollection(IEnumerable<Type> items)

src/Umbraco.Web/Mvc/SurfaceControllerTypeCollectionBuilder.cs

@@ -0,0 +1,8 @@
+using Umbraco.Core.Composing;
+using Umbraco.Web.WebApi;
+
+namespace Umbraco.Web.Mvc
+{
+    public class SurfaceControllerTypeCollectionBuilder : TypeCollectionBuilderBase<SurfaceControllerTypeCollection, SurfaceController>
+    { }
+}

src/Umbraco.Web/Runtime/WebRuntimeComposer.cs

@@ -156,12 +156,11 @@ namespace Umbraco.Web.Runtime
                 .Add(() => composition.TypeLoader.GetTypes<IAction>());
 
             //we need to eagerly scan controller types since they will need to be routed
-            var surfaceControllerTypes = new SurfaceControllerTypeCollection(composition.TypeLoader.GetSurfaceControllers());
-            composition.RegisterUnique(surfaceControllerTypes);
-
-            //we need to eagerly scan controller types since they will need to be routed
-            var umbracoApiControllerTypes = new UmbracoApiControllerTypeCollection(composition.TypeLoader.GetUmbracoApiControllers());
-            composition.RegisterUnique(umbracoApiControllerTypes);
+            composition.WithCollectionBuilder<SurfaceControllerTypeCollectionBuilder>()
+                .Add(composition.TypeLoader.GetSurfaceControllers());
+            var umbracoApiControllerTypes = composition.TypeLoader.GetUmbracoApiControllers().ToList();
+            composition.WithCollectionBuilder<UmbracoApiControllerTypeCollectionBuilder>()
+                .Add(umbracoApiControllerTypes);
 
             // both TinyMceValueConverter (in Core) and RteMacroRenderingValueConverter (in Web) will be
             // discovered when CoreBootManager configures the converters. We HAVE to remove one of them

src/Umbraco.Web/Umbraco.Web.csproj

@@ -204,6 +204,7 @@
     <Compile Include="Models\ContentEditing\MacroParameterDisplay.cs" />
     <Compile Include="Models\PublishedContent\HybridVariationContextAccessor.cs" />
     <Compile Include="Models\TemplateQuery\QueryConditionExtensions.cs" />
+    <Compile Include="Mvc\SurfaceControllerTypeCollectionBuilder.cs" />
     <Compile Include="Routing\IPublishedRouter.cs" />
     <Compile Include="Services\DashboardService.cs" />
     <Compile Include="Services\IDashboardService.cs" />
@@ -603,6 +604,7 @@
     <Compile Include="Editors\Filters\MemberSaveValidationAttribute.cs" />
     <Compile Include="WebApi\SessionHttpControllerRouteHandler.cs" />
     <Compile Include="WebApi\UmbracoApiControllerTypeCollection.cs" />
+    <Compile Include="WebApi\UmbracoApiControllerTypeCollectionBuilder.cs" />
     <Compile Include="WebApi\UnhandedExceptionLoggerConfigurationAttribute.cs" />
     <Compile Include="WebApi\UnhandledExceptionLogger.cs" />
     <Compile Include="Runtime\WebRuntimeComponent.cs" />

src/Umbraco.Web/WebApi/UmbracoApiControllerTypeCollection.cs

@@ -4,10 +4,6 @@ using Umbraco.Core.Composing;
 
 namespace Umbraco.Web.WebApi
 {
-    // unless we want to modify the content of the collection
-    // which we are not doing at the moment
-    // we can inherit from BuilderCollectionBase and just be enumerable
-
     public class UmbracoApiControllerTypeCollection : BuilderCollectionBase<Type>
     {
         public UmbracoApiControllerTypeCollection(IEnumerable<Type> items)

src/Umbraco.Web/WebApi/UmbracoApiControllerTypeCollectionBuilder.cs

@@ -0,0 +1,7 @@
+using Umbraco.Core.Composing;
+
+namespace Umbraco.Web.WebApi
+{
+    public class UmbracoApiControllerTypeCollectionBuilder : TypeCollectionBuilderBase<UmbracoApiControllerTypeCollection, UmbracoApiController>
+    { }
+}