Abstract base class for ISubscribeFilter (#911)

src/DotNetCore.CAP/Internal/Filter/SubscribeFilter.cs

@@ -0,0 +1,36 @@
+// Copyright (c) .NET Core Community. All rights reserved.
+// Licensed under the MIT License. See License.txt in the project root for license information.
+
+// ReSharper disable once CheckNamespace
+namespace DotNetCore.CAP.Filter
+{
+    /// <summary>
+    /// Abstract base class for ISubscribeFilter for use when implementing a subset of the interface methods.
+    /// </summary>
+    public abstract class SubscribeFilter : ISubscribeFilter
+    {
+        /// <summary>
+        /// Called before the subscriber executes.
+        /// </summary>
+        /// <param name="context">The <see cref="ExecutingContext"/>.</param>
+        public virtual void OnSubscribeExecuting(ExecutingContext context)
+        {
+        }
+
+        /// <summary>
+        /// Called after the subscriber executes.
+        /// </summary>
+        /// <param name="context">The <see cref="ExecutedContext"/>.</param>
+        public virtual void OnSubscribeExecuted(ExecutedContext context)
+        {
+        }
+
+        /// <summary>
+        /// Called after the subscriber has thrown an <see cref="System.Exception"/>.
+        /// </summary>
+        /// <param name="context">The <see cref="ExceptionContext"/>.</param>
+        public virtual void OnSubscribeException(ExceptionContext context)
+        {
+        }
+    }
+}