Managers

Libraries/Esiur/Resource/Attributes/AuditingManagerAttribute.cs

@@ -7,7 +7,10 @@ namespace Esiur.Resource;
 /// Associates a registered auditing-manager implementation with a resource type.
 /// </summary>
 [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
-public sealed class AuditingManagerAttribute<T> : Attribute
+public sealed class AuditingManagerAttribute<T> : ResourceManagerAttribute
     where T : IAuditingManager
 {
+    public AuditingManagerAttribute() : base(typeof(T))
+    {
+    }
 }

Libraries/Esiur/Resource/Attributes/PermissionsManagerAttribute.cs

@@ -7,7 +7,10 @@ namespace Esiur.Resource;
 /// Associates a registered permissions-manager implementation with a resource type.
 /// </summary>
 [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
-public sealed class PermissionsManagerAttribute<T> : Attribute
+public sealed class PermissionsManagerAttribute<T> : ResourceManagerAttribute
     where T : IPermissionsManager
 {
+    public PermissionsManagerAttribute() : base(typeof(T))
+    {
+    }
 }

Libraries/Esiur/Resource/Attributes/RateControlManagerAttribute.cs

@@ -7,7 +7,10 @@ namespace Esiur.Resource;
 /// Associates a registered rate-control-manager implementation with a resource type.
 /// </summary>
 [AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
-public sealed class RateControlManagerAttribute<T> : Attribute
+public sealed class RateControlManagerAttribute<T> : ResourceManagerAttribute
     where T : IRateControlManager
 {
+    public RateControlManagerAttribute() : base(typeof(T))
+    {
+    }
 }

Libraries/Esiur/Resource/Attributes/ResourceManagerAttribute.cs

@@ -0,0 +1,24 @@
+using Esiur.Security.Management;
+using System;
+
+namespace Esiur.Resource;
+
+/// <summary>
+/// Base metadata used to resolve a resource manager from its owning Warehouse.
+/// Manager attributes never create instances directly; the declared type must be
+/// registered with the Warehouse before the resource is created.
+/// </summary>
+public abstract class ResourceManagerAttribute : Attribute
+{
+    public Type ManagerType { get; }
+
+    protected ResourceManagerAttribute(Type managerType)
+    {
+        ManagerType = managerType ?? throw new ArgumentNullException(nameof(managerType));
+
+        if (!typeof(IResourceManager).IsAssignableFrom(managerType))
+            throw new ArgumentException(
+                $"Manager type `{managerType}` must implement {nameof(IResourceManager)}.",
+                nameof(managerType));
+    }
+}