init

Framework/Entities/Associations/AssociationAttribute.cs

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+using System;
+
+namespace Kreta.Framework.Entities.Associations
+{
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
+    public class AssociationAttribute : Attribute
+    {
+        public string AssociationName
+        {
+            get;
+            private set;
+        }
+
+        public AssociationAttribute(string associationName)
+        {
+            AssociationName = associationName;
+        }
+    }
+}

Framework/Entities/Associations/AssociationHandler.cs

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+namespace Kreta.Framework.Entities.Associations
+{
+    public class AssociationHandler<LeftEntity, RightEntity>
+        where LeftEntity : Entity
+        where RightEntity : Entity
+    {
+        internal protected AssociationHandler()
+        {
+            //for internal constructs only
+        }
+
+        public virtual void BeforeInsert(LeftEntity leftEntity, RightEntity rightEntity)
+        {
+            //dummy handler
+        }
+
+        public virtual void AfterInsert(LeftEntity leftEntity, RightEntity rightEntity)
+        {
+            //dummy handler
+        }
+
+        public virtual void BeforeDelete(LeftEntity leftEntity, RightEntity rightEntity)
+        {
+            //dummy handler
+        }
+
+        public virtual void AfterDelete(LeftEntity leftEntity, RightEntity rightEntity)
+        {
+            //dummy handler
+        }
+    }
+}

Framework/Entities/Associations/AssociationHandlerManager.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Kreta.Framework.Entities.Associations
+{
+    public static class AssociationHandlerManager
+    {
+        private static Dictionary<string, Type> associationHandlers = null;
+
+        private static void Initialize()
+        {
+            if (associationHandlers == null)
+            {
+                associationHandlers = new Dictionary<string, Type>();
+                var handlers = from assembly in AppDomain.CurrentDomain.GetAssemblies()
+                               where SDAServer.Instance.IsAssemblyAllowed(assembly)
+                               from type in assembly.GetTypes()
+                               where type.IsDefined(typeof(AssociationAttribute), false)
+                               select new
+                               {
+                                   AssociationName = ((AssociationAttribute)type.GetCustomAttributes(typeof(AssociationAttribute), false)[0]).AssociationName.ToLower(),
+                                   HandlerType = type,
+                               };
+                foreach (var handler in handlers)
+                {
+                    associationHandlers.Add(handler.AssociationName, handler.HandlerType);
+                }
+            }
+        }
+
+        public static AssociationHandler<LeftEntity, RightEntity> Create<LeftEntity, RightEntity>(string associationName)
+            where LeftEntity : Entity
+            where RightEntity : Entity
+        {
+            Initialize();
+
+            return associationHandlers.TryGetValue(associationName.ToLower(), out Type type)
+                ? (AssociationHandler<LeftEntity, RightEntity>)Activator.CreateInstance(type, true)
+                : new AssociationHandler<LeftEntity, RightEntity>();
+        }
+    }
+}