add feature of #22.

src/DotNetCore.CAP.SqlServer/CapPublisher.cs

@@ -11,7 +11,7 @@ using Microsoft.Extensions.Logging;
 
 namespace DotNetCore.CAP.SqlServer
 {
-    public class CapPublisher : CapPublisherBase
+    public class CapPublisher : CapPublisherBase, ICallbackPublisher
     {
         private readonly ILogger _logger;
         private readonly SqlServerOptions _options;
@@ -61,6 +61,14 @@ namespace DotNetCore.CAP.SqlServer
             _logger.LogInformation("Published Message has been persisted in the database. name:" + message.ToString());
         }
 
+        public Task PublishAsync(string name, object contentObj)
+        {
+            using (var conn = new SqlConnection(_options.ConnectionString))
+            {
+               return conn.ExecuteAsync(PrepareSql(), contentObj);
+            } 
+        }
+
         #region private methods
 
         private string PrepareSql()
@@ -68,7 +76,6 @@ namespace DotNetCore.CAP.SqlServer
             return $"INSERT INTO {_options.Schema}.[Published] ([Name],[Content],[Retries],[Added],[ExpiresAt],[StatusName])VALUES(@Name,@Content,@Retries,@Added,@ExpiresAt,@StatusName)";
         }
 
-
         #endregion private methods
     }
 }

src/DotNetCore.CAP/Abstractions/CapPublisherBase.cs

@@ -7,7 +7,7 @@ using DotNetCore.CAP.Processor;
 
 namespace DotNetCore.CAP.Abstractions
 {
-    public abstract class CapPublisherBase : ICapPublisher
+    public abstract class CapPublisherBase : ICapPublisher, IDisposable
     {
         protected IDbConnection DbConnection { get; set; }
         protected IDbTransaction DbTranasaction { get; set; }
@@ -16,44 +16,46 @@ namespace DotNetCore.CAP.Abstractions
         protected bool IsUsingEF { get; set; }
         protected IServiceProvider ServiceProvider { get; set; }
 
-        public void Publish<T>(string name, T contentObj)
+        public void Publish<T>(string name, T contentObj, string callbackName = null)
         {
             CheckIsUsingEF(name);
             PrepareConnectionForEF();
 
-            var content = Serialize(contentObj);
+            var content = Serialize(contentObj, callbackName);
 
-            PublishWithTrans(name, content, DbConnection, DbTranasaction);
+            PublishWithTrans(name, content);
         }
 
-        public Task PublishAsync<T>(string name, T contentObj)
+        public Task PublishAsync<T>(string name, T contentObj, string callbackName = null)
         {
             CheckIsUsingEF(name);
             PrepareConnectionForEF();
 
-            var content = Serialize(contentObj);
+            var content = Serialize(contentObj, callbackName);
 
-            return PublishWithTransAsync(name, content, DbConnection, DbTranasaction);
+            return PublishWithTransAsync(name, content);
         }
 
-        public void Publish<T>(string name, T contentObj, IDbConnection dbConnection, IDbTransaction dbTransaction = null)
+        public void Publish<T>(string name, T contentObj, IDbConnection dbConnection,
+            string callbackName = null, IDbTransaction dbTransaction = null)
         {
             CheckIsAdoNet(name);
-            PrepareConnectionForAdo(dbConnection, ref dbTransaction);
+            PrepareConnectionForAdo(dbConnection, dbTransaction);
 
-            var content = Serialize(contentObj);
+            var content = Serialize(contentObj, callbackName);
 
-            PublishWithTrans(name, content, dbConnection, dbTransaction);
+            PublishWithTrans(name, content);
         }
 
-        public Task PublishAsync<T>(string name, T contentObj, IDbConnection dbConnection, IDbTransaction dbTransaction = null)
+        public Task PublishAsync<T>(string name, T contentObj, IDbConnection dbConnection,
+            string callbackName = null, IDbTransaction dbTransaction = null)
         {
             CheckIsAdoNet(name);
-            PrepareConnectionForAdo(dbConnection, ref dbTransaction);
+            PrepareConnectionForAdo(dbConnection, dbTransaction);
 
-            var content = Serialize(contentObj);
+            var content = Serialize(contentObj, callbackName);
 
-            return PublishWithTransAsync(name, content, dbConnection, dbTransaction);
+            return PublishWithTransAsync(name, content);
         }
 
         protected abstract void PrepareConnectionForEF();
@@ -64,35 +66,29 @@ namespace DotNetCore.CAP.Abstractions
 
         #region private methods
 
-        private string Serialize<T>(T obj)
+        private string Serialize<T>(T obj, string callbackName = null)
         {
-            string content = string.Empty;
-            if (Helper.IsComplexType(typeof(T)))
+            var message = new Message(obj)
             {
-                content = Helper.ToJson(obj);
-            }
-            else
-            {
-                content = obj.ToString();
-            }
-            return content;
+                CallbackName = callbackName
+            };
+
+            return Helper.ToJson(message);
         }
 
-        private void PrepareConnectionForAdo(IDbConnection dbConnection, ref IDbTransaction dbTransaction)
+        private void PrepareConnectionForAdo(IDbConnection dbConnection, IDbTransaction dbTransaction)
         {
-            if (dbConnection == null)
-                throw new ArgumentNullException(nameof(dbConnection));
-
-            if (dbConnection.State != ConnectionState.Open)
+            DbConnection = dbConnection ?? throw new ArgumentNullException(nameof(dbConnection));
+            if (DbConnection.State != ConnectionState.Open)
             {
                 IsCapOpenedConn = true;
-                dbConnection.Open();
+                DbConnection.Open();
             }
-
-            if (dbTransaction == null)
+            DbTranasaction = dbTransaction;
+            if (DbTranasaction == null)
             {
                 IsCapOpenedTrans = true;
-                dbTransaction = dbConnection.BeginTransaction(IsolationLevel.ReadCommitted);
+                DbTranasaction = dbConnection.BeginTransaction(IsolationLevel.ReadCommitted);
             }
         }
 
@@ -111,7 +107,7 @@ namespace DotNetCore.CAP.Abstractions
                 throw new InvalidOperationException("If you are using the EntityFramework, you do not need to use this overloaded.");
         }
 
-        private async Task PublishWithTransAsync(string name, string content, IDbConnection dbConnection, IDbTransaction dbTransaction)
+        private async Task PublishWithTransAsync(string name, string content)
         {
             var message = new CapPublishedMessage
             {
@@ -120,23 +116,14 @@ namespace DotNetCore.CAP.Abstractions
                 StatusName = StatusName.Scheduled
             };
 
-            await ExecuteAsync(dbConnection, dbTransaction, message);
-
-            if (IsCapOpenedTrans)
-            {
-                dbTransaction.Commit();
-                dbTransaction.Dispose();
-            }
+            await ExecuteAsync(DbConnection, DbTranasaction, message);
 
-            if (IsCapOpenedConn)
-            {
-                dbConnection.Dispose();
-            }
+            ClosedCap();
 
             PublishQueuer.PulseEvent.Set();
         }
 
-        private void PublishWithTrans(string name, string content, IDbConnection dbConnection, IDbTransaction dbTransaction)
+        private void PublishWithTrans(string name, string content)
         {
             var message = new CapPublishedMessage
             {
@@ -145,19 +132,30 @@ namespace DotNetCore.CAP.Abstractions
                 StatusName = StatusName.Scheduled
             };
 
-            Execute(dbConnection, dbTransaction, message);
+            Execute(DbConnection, DbTranasaction, message);
 
+            ClosedCap();
+
+            PublishQueuer.PulseEvent.Set();
+        }
+
+        private void ClosedCap()
+        {
             if (IsCapOpenedTrans)
             {
-                dbTransaction.Commit();
-                dbTransaction.Dispose();
+                DbTranasaction.Commit();
+                DbTranasaction.Dispose();
             }
             if (IsCapOpenedConn)
             {
-                dbConnection.Dispose();
+                DbConnection.Dispose();
             }
+        }
 
-            PublishQueuer.PulseEvent.Set();
+        public void Dispose()
+        {
+            DbTranasaction?.Dispose();
+            DbConnection?.Dispose();
         }
 
         #endregion private methods

src/DotNetCore.CAP/ICallbackPublisher.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace DotNetCore.CAP
+{
+    public interface ICallbackPublisher
+    {
+        Task PublishAsync(string name, object obj);
+    }
+}

src/DotNetCore.CAP/ICapPublisher.cs

@@ -18,7 +18,8 @@ namespace DotNetCore.CAP
         /// <typeparam name="T">The type of conetent object.</typeparam>
         /// <param name="name">the topic name or exchange router key.</param>
         /// <param name="contentObj">message body content, that will be serialized of json.</param>
-        Task PublishAsync<T>(string name, T contentObj);
+        /// <param name="callbackName">callback subscriber name</param>
+        Task PublishAsync<T>(string name, T contentObj, string callbackName = null);
 
         /// <summary>
         /// (EntityFramework) Publish a object message.
@@ -30,24 +31,27 @@ namespace DotNetCore.CAP
         /// <typeparam name="T">The type of conetent object.</typeparam>
         /// <param name="name">the topic name or exchange router key.</param>
         /// <param name="contentObj">message body content, that will be serialized of json.</param>
-        void Publish<T>(string name, T contentObj);
+        /// <param name="callbackName">callback subscriber name</param>
+        void Publish<T>(string name, T contentObj, string callbackName = null);
 
         /// <summary>
         /// (ado.net) Asynchronous publish a object message.
         /// </summary>
         /// <param name="name">the topic name or exchange router key.</param>
         /// <param name="contentObj">message body content, that will be serialized of json.</param>
+        /// <param name="callbackName">callback subscriber name</param>
         /// <param name="dbConnection">the connection of <see cref="IDbConnection"/></param>
         /// <param name="dbTransaction">the transaction of <see cref="IDbTransaction"/></param>
-        Task PublishAsync<T>(string name, T contentObj, IDbConnection dbConnection, IDbTransaction dbTransaction = null);
+        Task PublishAsync<T>(string name, T contentObj, IDbConnection dbConnection, string callbackName = null, IDbTransaction dbTransaction = null);
 
         /// <summary>
         /// (ado.net) Publish a object message.
         /// </summary>
         /// <param name="name">the topic name or exchange router key.</param>
         /// <param name="contentObj">message body content, that will be serialized of json.</param>
+        /// <param name="callbackName">callback subscriber name</param>
         /// <param name="dbConnection">the connection of <see cref="IDbConnection"/></param>
         /// <param name="dbTransaction">the transaction of <see cref="IDbTransaction"/></param>
-        void Publish<T>(string name, T contentObj, IDbConnection dbConnection, IDbTransaction dbTransaction = null);
+        void Publish<T>(string name, T contentObj, IDbConnection dbConnection, string callbackName = null, IDbTransaction dbTransaction = null);
     }
 }

src/DotNetCore.CAP/Internal/IConsumerInvoker.Default.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Threading.Tasks;
 using DotNetCore.CAP.Abstractions;
+using DotNetCore.CAP.Infrastructure;
+using DotNetCore.CAP.Models;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 
@@ -37,31 +39,47 @@ namespace DotNetCore.CAP.Internal
                 var obj = ActivatorUtilities.GetServiceOrCreateInstance(_serviceProvider,
                _consumerContext.ConsumerDescriptor.ImplTypeInfo.AsType());
 
-                var value = _consumerContext.DeliverMessage.Content;
+                var jsonConent = _consumerContext.DeliverMessage.Content;
+
+                var message = Helper.FromJson<Message>(jsonConent);
+
+                object returnObj = null;
                 if (_executor.MethodParameters.Length > 0)
                 {
                     var firstParameter = _executor.MethodParameters[0];
                     try
                     {
                         var binder = _modelBinderFactory.CreateBinder(firstParameter);
-                        var result = await binder.BindModelAsync(value);
+                        var result = await binder.BindModelAsync(message.Content.ToString());
                         if (result.IsSuccess)
                         {
-                            _executor.Execute(obj, result.Model);
+                            returnObj = _executor.Execute(obj, result.Model);
                         }
                         else
                         {
-                            _logger.LogWarning($"Parameters:{firstParameter.Name} bind failed! the content is:" + value);
+                            _logger.LogWarning($"Parameters:{firstParameter.Name} bind failed! the content is:" + jsonConent);
                         }
                     }
                     catch (FormatException ex)
                     {
-                        _logger.ModelBinderFormattingException(_executor.MethodInfo?.Name, firstParameter.Name, value, ex);
+                        _logger.ModelBinderFormattingException(_executor.MethodInfo?.Name, firstParameter.Name, jsonConent, ex);
                     }
                 }
                 else
                 {
-                    _executor.Execute(obj);
+                    returnObj = _executor.Execute(obj);
+                }
+
+                //TODO :refactor
+                if (returnObj != null && !string.IsNullOrEmpty(message.CallbackName))
+                {
+                    var publisher = _serviceProvider.GetRequiredService<ICallbackPublisher>();
+                    var callbackMessage = new Message(returnObj)
+                    {
+                        Id = message.Id,
+                        Timestamp = DateTime.Now
+                    };
+                    await publisher.PublishAsync(message.CallbackName, callbackMessage);
                 }
             }
         }

src/DotNetCore.CAP/Internal/IModelBinder.ComplexType.cs

@@ -3,6 +3,7 @@ using System.Reflection;
 using System.Threading.Tasks;
 using DotNetCore.CAP.Abstractions.ModelBinding;
 using DotNetCore.CAP.Infrastructure;
+using DotNetCore.CAP.Models;
 
 namespace DotNetCore.CAP.Internal
 {
@@ -20,7 +21,11 @@ namespace DotNetCore.CAP.Internal
             try
             {
                 var type = _parameterInfo.ParameterType;
-                var value = Helper.FromJson(content, type);
+
+                var message = Helper.FromJson<Message>(content);
+
+                var value = Helper.FromJson(message.Content.ToString(), type);
+
                 return Task.FromResult(ModelBindingResult.Success(value));
             }
             catch (Exception)

src/DotNetCore.CAP/Models/Message.cs

@@ -0,0 +1,26 @@
+using System;
+
+namespace DotNetCore.CAP.Models
+{
+    public class Message
+    {
+        public string Id { get; set; }
+
+        public DateTime Timestamp { get; set; }
+
+        public object Content { get; set; }
+
+        public string CallbackName { get; set; }
+
+        public Message()
+        {
+            Id = ObjectId.GenerateNewStringId();
+            Timestamp = DateTime.Now;
+        }
+
+        public Message(object content) : this()
+        {
+            Content = content;
+        }
+    }
+}