From 7783cd0126962ac0b7ba51c519c562919f831c22 Mon Sep 17 00:00:00 2001
From: Halil ibrahim Kalkan <hi_kalkan@yahoo.com>
Date: Thu, 15 Nov 2018 16:16:49 +0300
Subject: [PATCH] Introduce GenericEventNameAttribute.

---
 .../RabbitMq/RabbitMqDistributedEventBus.cs   |  6 ++---
 .../{EventName.cs => EventNameAttribute.cs}   | 18 ++++++-------
 .../Abp/EventBus/GenericEventNameAttribute.cs | 24 +++++++++++++++++
 .../Volo/Abp/EventBus/IEventNameProvider.cs   |  9 +++++++
 .../GenericEventNameAttribute_Tests.cs        | 26 +++++++++++++++++++
 5 files changed, 71 insertions(+), 12 deletions(-)
 rename framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/{EventName.cs => EventNameAttribute.cs} (65%)
 create mode 100644 framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/GenericEventNameAttribute.cs
 create mode 100644 framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/IEventNameProvider.cs
 create mode 100644 framework/test/Volo.Abp.EventBus.Tests/Volo/Abp/EventBus/GenericEventNameAttribute_Tests.cs

diff --git a/framework/src/Volo.Abp.EventBus.Distributed.RabbitMQ/Volo/Abp/EventBus/Distributed/RabbitMq/RabbitMqDistributedEventBus.cs b/framework/src/Volo.Abp.EventBus.Distributed.RabbitMQ/Volo/Abp/EventBus/Distributed/RabbitMq/RabbitMqDistributedEventBus.cs
index 053b41dc5b..9f56304959 100644
--- a/framework/src/Volo.Abp.EventBus.Distributed.RabbitMQ/Volo/Abp/EventBus/Distributed/RabbitMq/RabbitMqDistributedEventBus.cs
+++ b/framework/src/Volo.Abp.EventBus.Distributed.RabbitMQ/Volo/Abp/EventBus/Distributed/RabbitMq/RabbitMqDistributedEventBus.cs
@@ -132,7 +132,7 @@ namespace Volo.Abp.EventBus.Distributed.RabbitMq
 
             if (handlerFactories.Count == 1) //TODO: Multi-threading!
             {
-                var eventName = EventNameAttribute.GetName(eventType);
+                var eventName = EventNameAttribute.GetNameOrDefault(eventType);
 
                 using (var channel = ConnectionPool.Get().CreateModel()) //TODO: Connection name per event!
                 {
@@ -203,7 +203,7 @@ namespace Volo.Abp.EventBus.Distributed.RabbitMq
 
         public override Task PublishAsync(Type eventType, object eventData)
         {
-            var eventName = EventNameAttribute.GetName(eventType);
+            var eventName = EventNameAttribute.GetNameOrDefault(eventType);
             var body = Serializer.Serialize(eventData);
 
             using (var channel = ConnectionPool.Get().CreateModel()) //TODO: Connection name per event!
@@ -232,7 +232,7 @@ namespace Volo.Abp.EventBus.Distributed.RabbitMq
                 eventType,
                 type =>
                 {
-                    var eventName = EventNameAttribute.GetName(type);
+                    var eventName = EventNameAttribute.GetNameOrDefault(type);
                     EventTypes[eventName] = type;
                     return new List<IEventHandlerFactory>();
                 }
diff --git a/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/EventName.cs b/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/EventNameAttribute.cs
similarity index 65%
rename from framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/EventName.cs
rename to framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/EventNameAttribute.cs
index 3d634c76f5..7dfc0a434e 100644
--- a/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/EventName.cs
+++ b/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/EventNameAttribute.cs
@@ -7,19 +7,19 @@ namespace Volo.Abp.EventBus
     [AttributeUsage(AttributeTargets.Class)]
     public class EventNameAttribute : Attribute, IEventNameProvider
     {
-        public string Name { get; }
+        public virtual string Name { get; }
 
         public EventNameAttribute([NotNull] string name)
         {
             Name = Check.NotNullOrWhiteSpace(name, nameof(name));
         }
 
-        public static string GetName<TEvent>()
+        public static string GetNameOrDefault<TEvent>()
         {
-            return GetName(typeof(TEvent));
+            return GetNameOrDefault(typeof(TEvent));
         }
 
-        public static string GetName([NotNull] Type eventType)
+        public static string GetNameOrDefault([NotNull] Type eventType)
         {
             Check.NotNull(eventType, nameof(eventType));
 
@@ -27,13 +27,13 @@ namespace Volo.Abp.EventBus
                        .GetCustomAttributes(true)
                        .OfType<IEventNameProvider>()
                        .FirstOrDefault()
-                       ?.Name
+                       ?.GetName(eventType)
                    ?? eventType.FullName;
         }
-    }
 
-    public interface IEventNameProvider
-    {
-        string Name { get; }
+        public string GetName(Type eventType)
+        {
+            return Name;
+        }
     }
 }
diff --git a/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/GenericEventNameAttribute.cs b/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/GenericEventNameAttribute.cs
new file mode 100644
index 0000000000..638a47af0a
--- /dev/null
+++ b/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/GenericEventNameAttribute.cs
@@ -0,0 +1,24 @@
+using System;
+
+namespace Volo.Abp.EventBus
+{
+    [AttributeUsage(AttributeTargets.Class)]
+    public class GenericEventNameAttribute : Attribute, IEventNameProvider
+    {
+        public string GetName(Type eventType)
+        {
+            if (!eventType.IsGenericType)
+            {
+                throw new AbpException($"Given type is not generic: {eventType.AssemblyQualifiedName}");
+            }
+
+            var genericArguments = eventType.GetGenericArguments();
+            if (genericArguments.Length > 1)
+            {
+                throw new AbpException($"Given type has more than one generic argument: {eventType.AssemblyQualifiedName}");
+            }
+
+            return EventNameAttribute.GetNameOrDefault(genericArguments[0]);
+        }
+    }
+}
\ No newline at end of file
diff --git a/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/IEventNameProvider.cs b/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/IEventNameProvider.cs
new file mode 100644
index 0000000000..25d95c8329
--- /dev/null
+++ b/framework/src/Volo.Abp.EventBus/Volo/Abp/EventBus/IEventNameProvider.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace Volo.Abp.EventBus
+{
+    public interface IEventNameProvider
+    {
+        string GetName(Type eventType);
+    }
+}
\ No newline at end of file
diff --git a/framework/test/Volo.Abp.EventBus.Tests/Volo/Abp/EventBus/GenericEventNameAttribute_Tests.cs b/framework/test/Volo.Abp.EventBus.Tests/Volo/Abp/EventBus/GenericEventNameAttribute_Tests.cs
new file mode 100644
index 0000000000..640801ad58
--- /dev/null
+++ b/framework/test/Volo.Abp.EventBus.Tests/Volo/Abp/EventBus/GenericEventNameAttribute_Tests.cs
@@ -0,0 +1,26 @@
+using Shouldly;
+using Xunit;
+
+namespace Volo.Abp.EventBus
+{
+    public class GenericEventNameAttribute_Tests
+    {
+        [Fact]
+        public void Should_Properly_Get_EventName()
+        {
+            new GenericEventNameAttribute()
+                .GetName(typeof(MyGenericType<MyInnerType>))
+                .ShouldBe(typeof(MyInnerType).FullName);
+        }
+
+        public class MyInnerType
+        {
+
+        }
+
+        public class MyGenericType<T>
+        {
+
+        }
+    }
+}