* moved WelcomeAttribute to a separate namespace for special case-targetted attribute

* Added "MethodHandlerDescriptor" a class that provides ability to implicitly create handlers from methods that matches the AbstractHandlerAction<T> delegate
* Added extension method for HandlersCollection for adding methods as handlers

Telegrator/Annotations/Targetted/WelcomeAttribute.cs

@@ -2,7 +2,7 @@
 using Telegram.Bot.Types.Enums;
 using Telegrator.Filters;
 
-namespace Telegrator.Annotations
+namespace Telegrator.Annotations.Targetted
 {
     /// <summary>
     /// Attribute for filtering message with command "start" in bot's private chats.

Telegrator/Handlers/Building/HandlerBuilder.cs

@@ -1,5 +1,4 @@
 using Telegram.Bot.Types.Enums;
-using Telegrator.Providers;
 using Telegrator.Handlers.Building.Components;
 using Telegrator.MadiatorCore;
 

Telegrator/MadiatorCore/Descriptors/DefaultCustomDescriptors.cs

@@ -1,24 +1,53 @@
-using System;
-using System.Collections.Generic;
-using System.Reflection;
-using System.Text;
+using System.Reflection;
+using Telegram.Bot.Types;
+using Telegram.Bot.Types.Enums;
+using Telegrator.Attributes.Components;
+using Telegrator.Filters.Components;
 using Telegrator.Handlers;
+using Telegrator.Handlers.Building;
 using Telegrator.Handlers.Components;
 
 namespace Telegrator.MadiatorCore.Descriptors
 {
-    /*
-    public class MethodHandlerDescriptor : HandlerDescriptor
+    public class MethodHandlerDescriptor<TUpdate> : HandlerDescriptor where TUpdate : class
     {
-        public MethodHandlerDescriptor() : base(DescriptorType.General, )
+        public MethodHandlerDescriptor(AbstractHandlerAction<TUpdate> action) : base(DescriptorType.General)
+        {
+            UpdateHandlerAttributeBase handlerAttribute = HandlerInspector.GetHandlerAttribute(action.Method);
+            StateKeeperAttributeBase? stateKeeperAttribute = HandlerInspector.GetStateKeeperAttribute(action.Method);
+            IFilter<Update>[] filters = HandlerInspector.GetFilterAttributes(action.Method, handlerAttribute.Type).ToArray();
+
+            UpdateType = handlerAttribute.Type;
+            Indexer = handlerAttribute.GetIndexer();
+            Filters = new DescriptorFiltersSet(handlerAttribute, stateKeeperAttribute, filters);
+            DisplayString = HandlerInspector.GetDisplayName(action.Method);
+            InstanceFactory = () => new MethodHandler(action.Method, UpdateType);
         }
 
-    public class MethodHandler<TUpdate> : AbstractUpdateHandler<TUpdate>
-    {
-        public override Task Execute(IAbstractHandlerContainer<TUpdate> container, CancellationToken cancellation)
+        private class MethodHandler(MethodInfo method, UpdateType updateType) : AbstractUpdateHandler<TUpdate>(updateType)
         {
+            private readonly MethodInfo Method = method;
 
+            public override async Task Execute(IAbstractHandlerContainer<TUpdate> container, CancellationToken cancellation)
+            {
+                if (Method is null)
+                    throw new Exception();
+
+                if (Method.ReturnType == typeof(void))
+                {
+                    Method.Invoke(this, [container, cancellation]);
+                    return;
+                }
+                else
+                {
+                    object branchReturn = Method.Invoke(this, [container, cancellation]);
+                    if (branchReturn == null)
+                        return;
+
+                    if (branchReturn is Task branchTask)
+                        await branchTask;
+                }
+            }
         }
     }
-    */
 }

Telegrator/MadiatorCore/Descriptors/HandlerDescriptor.cs

@@ -61,7 +61,7 @@ namespace Telegrator.MadiatorCore.Descriptors
         public UpdateType UpdateType
         {
             get;
-            private set;
+            protected set;
         }
 
         /// <summary>
@@ -79,7 +79,7 @@ namespace Telegrator.MadiatorCore.Descriptors
         public DescriptorFiltersSet Filters
         {
             get;
-            private set;
+            protected set;
         }
 
         /// <summary>
@@ -88,7 +88,7 @@ namespace Telegrator.MadiatorCore.Descriptors
         public object? ServiceKey
         {
             get;
-            private set;
+            protected set;
         }
 
         /// <summary>
@@ -97,7 +97,7 @@ namespace Telegrator.MadiatorCore.Descriptors
         public Func<UpdateHandlerBase>? InstanceFactory
         {
             get;
-            private set;
+            protected set;
         }
 
         /// <summary>
@@ -106,7 +106,7 @@ namespace Telegrator.MadiatorCore.Descriptors
         public UpdateHandlerBase? SingletonInstance
         {
             get;
-            set;
+            protected set;
         }
 
         /// <summary>
@@ -127,6 +127,13 @@ namespace Telegrator.MadiatorCore.Descriptors
             set;
         }
 
+        internal HandlerDescriptor(DescriptorType descriptorType)
+        {
+            Type = descriptorType;
+            HandlerType = null!;
+            Filters = new DescriptorFiltersSet(null, null, null);
+        }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="HandlerDescriptor"/> class with the specified descriptor type and handler type.
         /// Automatically inspects the handler type to extract attributes, filters, and configuration.
@@ -413,6 +420,14 @@ namespace Telegrator.MadiatorCore.Descriptors
             InstanceFactory = instanceFactory ?? throw new ArgumentNullException(nameof(instanceFactory));
         }
 
+        public void SetInstance(UpdateHandlerBase instance)
+        {
+            if (SingletonInstance != null)
+                throw new Exception();
+
+            SingletonInstance = instance;
+        }
+
         /// <inheritdoc/>
         public override string ToString()
             => DisplayString ?? HandlerType.Name;

Telegrator/TypesExtensions.cs

@@ -356,12 +356,19 @@ namespace Telegrator
         public static HandlerBuilder<CallbackQuery> CreateCallbackQuery(this IHandlersCollection handlers)
             => handlers.CreateHandler<CallbackQuery>(UpdateType.CallbackQuery);
 
-        /*
-        public static IHandlersCollection AddMethod<TUpdate>(this IHandlersCollection handlers, Func<IAbstractHandlerContainer<TUpdate>, CancellationToken, Task> method)
+        /// <summary>
+        /// Creates implicit handler from method
+        /// </summary>
+        /// <typeparam name="TUpdate"></typeparam>
+        /// <param name="handlers"></param>
+        /// <param name="method"></param>
+        /// <returns></returns>
+        public static IHandlersCollection AddMethod<TUpdate>(this IHandlersCollection handlers, AbstractHandlerAction<TUpdate> method) where TUpdate : class
         {
-
+            MethodHandlerDescriptor<TUpdate> descriptor = new MethodHandlerDescriptor<TUpdate>(method);
+            handlers.AddDescriptor(descriptor);
+            return handlers;
         }
-        */
     }
 
     /// <summary>