Add middlewares (API + Docs + Tests)

aiogram/__init__.py

@@ -3,6 +3,7 @@ from .api.client import session
 from .api.client.bot import Bot
 from .dispatcher import filters, handler
 from .dispatcher.dispatcher import Dispatcher
+from .dispatcher.middlewares.base import BaseMiddleware
 from .dispatcher.router import Router
 
 try:
@@ -22,6 +23,7 @@ __all__ = (
     "session",
     "Dispatcher",
     "Router",
+    "BaseMiddleware",
     "filters",
     "handler",
 )

aiogram/api/types/message.py

@@ -240,6 +240,8 @@ class Message(TelegramObject):
             return ContentType.PASSPORT_DATA
         if self.poll:
             return ContentType.POLL
+        if self.dice:
+            return ContentType.DICE
 
         return ContentType.UNKNOWN
 

aiogram/dispatcher/event/observer.py

@@ -1,21 +1,12 @@
 from __future__ import annotations
 
 from itertools import chain
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    AsyncGenerator,
-    Callable,
-    Dict,
-    Generator,
-    List,
-    Optional,
-    Type,
-)
+from typing import TYPE_CHECKING, Any, AsyncGenerator, Callable, Dict, Generator, List, Type
 
 from pydantic import ValidationError
 
 from ..filters.base import BaseFilter
+from ..middlewares.types import MiddlewareStep, UpdateType
 from .handler import CallbackType, FilterObject, FilterType, HandlerObject, HandlerType
 
 if TYPE_CHECKING:  # pragma: no cover
@@ -95,10 +86,8 @@ class TelegramEventObserver(EventObserver):
         """
         registry: List[Type[BaseFilter]] = []
 
-        router: Optional[Router] = self.router
-        while router:
+        for router in self.router.chain:
             observer = router.observers[self.event_name]
-            router = router.parent_router
 
             for filter_ in observer.filters:
                 if filter_ in registry:
@@ -133,6 +122,37 @@ class TelegramEventObserver(EventObserver):
 
         return filters
 
+    async def trigger_middleware(
+        self, step: MiddlewareStep, event: UpdateType, data: Dict[str, Any], result: Any = None,
+    ) -> None:
+        """
+        Trigger middlewares chain
+
+        :param step:
+        :param event:
+        :param data:
+        :param result:
+        :return:
+        """
+        reverse = step == MiddlewareStep.POST_PROCESS
+        recursive = self.event_name == "update" or step == MiddlewareStep.PROCESS
+
+        if self.event_name == "update":
+            routers = self.router.chain
+        else:
+            routers = self.router.chain_head
+        for router in routers:
+            await router.middleware.trigger(
+                step=step,
+                event_name=self.event_name,
+                event=event,
+                data=data,
+                result=result,
+                reverse=reverse,
+            )
+            if not recursive:
+                break
+
     def register(
         self, callback: HandlerType, *filters: FilterType, **bound_filters: Any
     ) -> HandlerType:
@@ -153,12 +173,24 @@ class TelegramEventObserver(EventObserver):
         Propagate event to handlers and stops propagation on first match.
         Handler will be called when all its filters is pass.
         """
+        event = args[0]
+        await self.trigger_middleware(step=MiddlewareStep.PRE_PROCESS, event=event, data=kwargs)
         for handler in self.handlers:
             result, data = await handler.check(*args, **kwargs)
             if result:
                 kwargs.update(data)
+                await self.trigger_middleware(
+                    step=MiddlewareStep.PROCESS, event=event, data=kwargs
+                )
                 try:
-                    yield await handler.call(*args, **kwargs)
+                    response = await handler.call(*args, **kwargs)
+                    await self.trigger_middleware(
+                        step=MiddlewareStep.POST_PROCESS,
+                        event=event,
+                        data=kwargs,
+                        result=response,
+                    )
+                    yield response
                 except SkipHandler:
                     continue
                 break

aiogram/dispatcher/middlewares/abstract.py

@@ -0,0 +1,61 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from typing import TYPE_CHECKING, Any, Dict, Optional
+
+from aiogram.dispatcher.middlewares.types import MiddlewareStep, UpdateType
+
+if TYPE_CHECKING:  # pragma: no cover
+    from aiogram.dispatcher.middlewares.manager import MiddlewareManager
+
+
+class AbstractMiddleware(ABC):
+    """
+    Abstract class for middleware.
+    """
+
+    def __init__(self) -> None:
+        self._manager: Optional[MiddlewareManager] = None
+
+    @property
+    def manager(self) -> MiddlewareManager:
+        """
+        Instance of MiddlewareManager
+        """
+        if self._manager is None:
+            raise RuntimeError("Middleware is not configured!")
+        return self._manager
+
+    def setup(self, manager: MiddlewareManager, _stack_level: int = 1) -> AbstractMiddleware:
+        """
+        Mark middleware as configured
+
+        :param manager:
+        :param _stack_level:
+        :return:
+        """
+        if self.configured:
+            return manager.setup(self, _stack_level=_stack_level + 1)
+
+        self._manager = manager
+        return self
+
+    @property
+    def configured(self) -> bool:
+        """
+        Check middleware is configured
+
+        :return:
+        """
+        return bool(self._manager)
+
+    @abstractmethod
+    async def trigger(
+        self,
+        step: MiddlewareStep,
+        event_name: str,
+        event: UpdateType,
+        data: Dict[str, Any],
+        result: Any = None,
+    ) -> Any:  # pragma: no cover
+        pass

aiogram/dispatcher/middlewares/base.py

@@ -0,0 +1,300 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Dict
+
+from aiogram.dispatcher.middlewares.abstract import AbstractMiddleware
+from aiogram.dispatcher.middlewares.types import MiddlewareStep, UpdateType
+
+if TYPE_CHECKING:  # pragma: no cover
+    from aiogram.api.types import (
+        CallbackQuery,
+        ChosenInlineResult,
+        InlineQuery,
+        Message,
+        Poll,
+        PollAnswer,
+        PreCheckoutQuery,
+        ShippingQuery,
+        Update,
+    )
+
+
+class BaseMiddleware(AbstractMiddleware):
+    """
+    Base class for middleware.
+
+    All methods on the middle always must be coroutines and name starts with "on_" like "on_process_message".
+    """
+
+    async def trigger(
+        self,
+        step: MiddlewareStep,
+        event_name: str,
+        event: UpdateType,
+        data: Dict[str, Any],
+        result: Any = None,
+    ) -> Any:
+        """
+        Trigger action.
+
+        :param step:
+        :param event_name:
+        :param event:
+        :param data:
+        :param result:
+        :return:
+        """
+        handler_name = f"on_{step.value}_{event_name}"
+        handler = getattr(self, handler_name, None)
+        if not handler:
+            return None
+        args = (event, result, data) if step == MiddlewareStep.POST_PROCESS else (event, data)
+        return await handler(*args)
+
+    if TYPE_CHECKING:  # pragma: no cover
+        # =============================================================================================
+        # Event that triggers before process <event>
+        # =============================================================================================
+        async def on_pre_process_update(self, update: Update, data: Dict[str, Any]) -> Any:
+            """
+            Event that triggers before process update
+            """
+
+        async def on_pre_process_message(self, message: Message, data: Dict[str, Any]) -> Any:
+            """
+            Event that triggers before process message
+            """
+
+        async def on_pre_process_edited_message(
+            self, edited_message: Message, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process edited_message
+            """
+
+        async def on_pre_process_channel_post(
+            self, channel_post: Message, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process channel_post
+            """
+
+        async def on_pre_process_edited_channel_post(
+            self, edited_channel_post: Message, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process edited_channel_post
+            """
+
+        async def on_pre_process_inline_query(
+            self, inline_query: InlineQuery, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process inline_query
+            """
+
+        async def on_pre_process_chosen_inline_result(
+            self, chosen_inline_result: ChosenInlineResult, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process chosen_inline_result
+            """
+
+        async def on_pre_process_callback_query(
+            self, callback_query: CallbackQuery, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process callback_query
+            """
+
+        async def on_pre_process_shipping_query(
+            self, shipping_query: ShippingQuery, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process shipping_query
+            """
+
+        async def on_pre_process_pre_checkout_query(
+            self, pre_checkout_query: PreCheckoutQuery, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process pre_checkout_query
+            """
+
+        async def on_pre_process_poll(self, poll: Poll, data: Dict[str, Any]) -> Any:
+            """
+            Event that triggers before process poll
+            """
+
+        async def on_pre_process_poll_answer(
+            self, poll_answer: PollAnswer, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers before process poll_answer
+            """
+
+        # =============================================================================================
+        # Event that triggers on process <event> after filters.
+        # =============================================================================================
+        async def on_process_update(self, update: Update, data: Dict[str, Any]) -> Any:
+            """
+            Event that triggers on process update
+            """
+
+        async def on_process_message(self, message: Message, data: Dict[str, Any]) -> Any:
+            """
+            Event that triggers on process message
+            """
+
+        async def on_process_edited_message(
+            self, edited_message: Message, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process edited_message
+            """
+
+        async def on_process_channel_post(
+            self, channel_post: Message, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process channel_post
+            """
+
+        async def on_process_edited_channel_post(
+            self, edited_channel_post: Message, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process edited_channel_post
+            """
+
+        async def on_process_inline_query(
+            self, inline_query: InlineQuery, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process inline_query
+            """
+
+        async def on_process_chosen_inline_result(
+            self, chosen_inline_result: ChosenInlineResult, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process chosen_inline_result
+            """
+
+        async def on_process_callback_query(
+            self, callback_query: CallbackQuery, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process callback_query
+            """
+
+        async def on_process_shipping_query(
+            self, shipping_query: ShippingQuery, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process shipping_query
+            """
+
+        async def on_process_pre_checkout_query(
+            self, pre_checkout_query: PreCheckoutQuery, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process pre_checkout_query
+            """
+
+        async def on_process_poll(self, poll: Poll, data: Dict[str, Any]) -> Any:
+            """
+            Event that triggers on process poll
+            """
+
+        async def on_process_poll_answer(
+            self, poll_answer: PollAnswer, data: Dict[str, Any]
+        ) -> Any:
+            """
+            Event that triggers on process poll_answer
+            """
+
+        # =============================================================================================
+        # Event that triggers after process <event>.
+        # =============================================================================================
+        async def on_post_process_update(
+            self, update: Update, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing update
+            """
+
+        async def on_post_process_message(
+            self, message: Message, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing message
+            """
+
+        async def on_post_process_edited_message(
+            self, edited_message: Message, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing edited_message
+            """
+
+        async def on_post_process_channel_post(
+            self, channel_post: Message, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing channel_post
+            """
+
+        async def on_post_process_edited_channel_post(
+            self, edited_channel_post: Message, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing edited_channel_post
+            """
+
+        async def on_post_process_inline_query(
+            self, inline_query: InlineQuery, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing inline_query
+            """
+
+        async def on_post_process_chosen_inline_result(
+            self, chosen_inline_result: ChosenInlineResult, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing chosen_inline_result
+            """
+
+        async def on_post_process_callback_query(
+            self, callback_query: CallbackQuery, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing callback_query
+            """
+
+        async def on_post_process_shipping_query(
+            self, shipping_query: ShippingQuery, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing shipping_query
+            """
+
+        async def on_post_process_pre_checkout_query(
+            self, pre_checkout_query: PreCheckoutQuery, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing pre_checkout_query
+            """
+
+        async def on_post_process_poll(self, poll: Poll, data: Dict[str, Any], result: Any) -> Any:
+            """
+            Event that triggers after processing poll
+            """
+
+        async def on_post_process_poll_answer(
+            self, poll_answer: PollAnswer, data: Dict[str, Any], result: Any
+        ) -> Any:
+            """
+            Event that triggers after processing poll_answer
+            """

aiogram/dispatcher/middlewares/manager.py

@@ -0,0 +1,71 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Dict, List
+from warnings import warn
+
+from .abstract import AbstractMiddleware
+from .types import MiddlewareStep, UpdateType
+
+if TYPE_CHECKING:  # pragma: no cover
+    from aiogram.dispatcher.router import Router
+
+
+class MiddlewareManager:
+    """
+    Middleware manager.
+    """
+
+    def __init__(self, router: Router) -> None:
+        self.router = router
+        self.middlewares: List[AbstractMiddleware] = []
+
+    def setup(self, middleware: AbstractMiddleware, _stack_level: int = 1) -> AbstractMiddleware:
+        """
+        Setup middleware
+
+        :param middleware:
+        :param _stack_level:
+        :return:
+        """
+        if not isinstance(middleware, AbstractMiddleware):
+            raise TypeError(
+                f"`middleware` should be instance of BaseMiddleware, not {type(middleware)}"
+            )
+        if middleware.configured:
+            if middleware.manager is self:
+                warn(
+                    f"Middleware {middleware} is already configured for this Router "
+                    "That's mean re-installing of this middleware has no effect.",
+                    category=RuntimeWarning,
+                    stacklevel=_stack_level + 1,
+                )
+                return middleware
+            raise ValueError(
+                f"Middleware is already configured for another manager {middleware.manager} "
+                f"in router {middleware.manager.router}!"
+            )
+
+        self.middlewares.append(middleware)
+        middleware.setup(self)
+        return middleware
+
+    async def trigger(
+        self,
+        step: MiddlewareStep,
+        event_name: str,
+        event: UpdateType,
+        data: Dict[str, Any],
+        result: Any = None,
+        reverse: bool = False,
+    ) -> Any:
+        """
+        Call action to middlewares with args lilt.
+        """
+        middlewares = reversed(self.middlewares) if reverse else self.middlewares
+        for middleware in middlewares:
+            await middleware.trigger(
+                step=step, event_name=event_name, event=event, data=data, result=result
+            )
+
+    def __contains__(self, item: AbstractMiddleware) -> bool:
+        return item in self.middlewares

aiogram/dispatcher/middlewares/types.py

@@ -0,0 +1,34 @@
+from __future__ import annotations
+
+from enum import Enum
+from typing import Union
+
+from aiogram.api.types import (
+    CallbackQuery,
+    ChosenInlineResult,
+    InlineQuery,
+    Message,
+    Poll,
+    PollAnswer,
+    PreCheckoutQuery,
+    ShippingQuery,
+    Update,
+)
+
+UpdateType = Union[
+    CallbackQuery,
+    ChosenInlineResult,
+    InlineQuery,
+    Message,
+    Poll,
+    PollAnswer,
+    PreCheckoutQuery,
+    ShippingQuery,
+    Update,
+]
+
+
+class MiddlewareStep(Enum):
+    PRE_PROCESS = "pre_process"
+    PROCESS = "process"
+    POST_PROCESS = "post_process"

aiogram/dispatcher/router.py

@@ -1,13 +1,15 @@
 from __future__ import annotations
 
 import warnings
-from typing import Any, Dict, List, Optional, Union
+from typing import Any, Dict, Generator, List, Optional, Union
 
 from ..api.types import Chat, TelegramObject, Update, User
 from ..utils.imports import import_module
 from ..utils.warnings import CodeHasNoEffect
 from .event.observer import EventObserver, SkipHandler, TelegramEventObserver
 from .filters import BUILTIN_FILTERS
+from .middlewares.abstract import AbstractMiddleware
+from .middlewares.manager import MiddlewareManager
 
 
 class Router:
@@ -46,6 +48,7 @@ class Router:
         )
         self.poll_handler = TelegramEventObserver(router=self, event_name="poll")
         self.poll_answer_handler = TelegramEventObserver(router=self, event_name="poll_answer")
+        self.middleware = MiddlewareManager(router=self)
 
         self.startup = EventObserver()
         self.shutdown = EventObserver()
@@ -74,6 +77,36 @@ class Router:
                 for builtin_filter in BUILTIN_FILTERS.get(name, ()):
                     observer.bind_filter(builtin_filter)
 
+    @property
+    def chain_head(self) -> Generator[Router, None, None]:
+        router: Optional[Router] = self
+        while router:
+            yield router
+            router = router.parent_router
+
+    @property
+    def chain_tail(self) -> Generator[Router, None, None]:
+        yield self
+        for router in self.sub_routers:
+            yield from router.chain_tail
+
+    @property
+    def chain(self) -> Generator[Router, None, None]:
+        yield from self.chain_head
+        tail = self.chain_tail
+        next(tail)  # Skip self
+        yield from tail
+
+    def use(self, middleware: AbstractMiddleware, _stack_level: int = 1) -> AbstractMiddleware:
+        """
+        Use middleware
+
+        :param middleware:
+        :param _stack_level:
+        :return:
+        """
+        return self.middleware.setup(middleware, _stack_level=_stack_level + 1)
+
     @property
     def parent_router(self) -> Optional[Router]:
         return self._parent_router

aiogram/loggers.py

@@ -1,3 +1,4 @@
 import logging
 
 dispatcher = logging.getLogger("aiogram.dispatcher")
+middlewares = logging.getLogger("aiogram.middlewares")

docs/dispatcher/middlewares/basics.md

@@ -0,0 +1,111 @@
+# Basics
+
+All middlewares should be made with `BaseMiddleware` (`#!python3 from aiogram import BaseMiddleware`) as base class.
+
+For example:
+
+```python3
+class MyMiddleware(BaseMiddleware): ...
+```
+
+And then use next pattern in naming callback functions in middleware: `on_{step}_{event}`
+
+Where is:
+
+- `#!python3 step`:
+    - `#!python3 pre_process` 
+    - `#!python3 process` 
+    - `#!python3 post_process` 
+- `#!python3 event`:
+    - `#!python3 update`
+    - `#!python3 message`
+    - `#!python3 edited_message`
+    - `#!python3 channel_post`
+    - `#!python3 edited_channel_post`
+    - `#!python3 inline_query`
+    - `#!python3 chosen_inline_result`
+    - `#!python3 callback_query`
+    - `#!python3 shipping_query`
+    - `#!python3 pre_checkout_query`
+    - `#!python3 poll`
+    - `#!python3 poll_answer`
+
+## Connecting middleware with router
+
+Middlewares can be connected with router by next ways:
+
+1. `#!python3 router.use(MyMiddleware())` (**recommended**)
+1. `#!python3 router.middleware.setup(MyMiddleware())`
+1. `#!python3 MyMiddleware().setup(router.middleware)` (**not recommended**)
+
+!!! warning
+    One instance of middleware **can't** be registered twice in single or many middleware managers
+
+## The specification of step callbacks
+
+### Pre-process step
+
+| Argument | Type | Description |
+| --- | --- | --- |
+| event name | Any of event type (Update, Message and etc.) | Event |
+| `#!python3 data` | `#!python3 Dict[str, Any]` | Contextual data (Will be mapped to handler arguments) |
+
+Returns `#!python3 Any`
+
+### Process step
+
+| Argument | Type | Description |
+| --- | --- | --- |
+| event name | Any of event type (Update, Message and etc.) | Event |
+| `#!python3 data` | `#!python3 Dict[str, Any]` | Contextual data (Will be mapped to handler arguments) |
+
+Returns `#!python3 Any`
+
+### Post-Process step
+
+| Argument | Type | Description |
+| --- | --- | --- |
+| event name | Any of event type (Update, Message and etc.) | Event |
+| `#!python3 data` | `#!python3 Dict[str, Any]` | Contextual data (Will be mapped to handler arguments) |
+| `#!python3 result` | `#!python3 Dict[str, Any]` | Response from handlers |
+
+Returns `#!python3 Any`
+
+## Full list of available callbacks
+
+- `#!python3 on_pre_process_update` - will be triggered on **pre process** `#!python3 update` event
+- `#!python3 on_process_update` - will be triggered on **process** `#!python3 update` event
+- `#!python3 on_post_process_update` - will be triggered on **post process** `#!python3 update` event
+- `#!python3 on_pre_process_message` - will be triggered on **pre process** `#!python3 message` event
+- `#!python3 on_process_message` - will be triggered on **process** `#!python3 message` event
+- `#!python3 on_post_process_message` - will be triggered on **post process** `#!python3 message` event
+- `#!python3 on_pre_process_edited_message` - will be triggered on **pre process** `#!python3 edited_message` event
+- `#!python3 on_process_edited_message` - will be triggered on **process** `#!python3 edited_message` event
+- `#!python3 on_post_process_edited_message` - will be triggered on **post process** `#!python3 edited_message` event
+- `#!python3 on_pre_process_channel_post` - will be triggered on **pre process** `#!python3 channel_post` event
+- `#!python3 on_process_channel_post` - will be triggered on **process** `#!python3 channel_post` event
+- `#!python3 on_post_process_channel_post` - will be triggered on **post process** `#!python3 channel_post` event
+- `#!python3 on_pre_process_edited_channel_post` - will be triggered on **pre process** `#!python3 edited_channel_post` event
+- `#!python3 on_process_edited_channel_post` - will be triggered on **process** `#!python3 edited_channel_post` event
+- `#!python3 on_post_process_edited_channel_post` - will be triggered on **post process** `#!python3 edited_channel_post` event
+- `#!python3 on_pre_process_inline_query` - will be triggered on **pre process** `#!python3 inline_query` event
+- `#!python3 on_process_inline_query` - will be triggered on **process** `#!python3 inline_query` event
+- `#!python3 on_post_process_inline_query` - will be triggered on **post process** `#!python3 inline_query` event
+- `#!python3 on_pre_process_chosen_inline_result` - will be triggered on **pre process** `#!python3 chosen_inline_result` event
+- `#!python3 on_process_chosen_inline_result` - will be triggered on **process** `#!python3 chosen_inline_result` event
+- `#!python3 on_post_process_chosen_inline_result` - will be triggered on **post process** `#!python3 chosen_inline_result` event
+- `#!python3 on_pre_process_callback_query` - will be triggered on **pre process** `#!python3 callback_query` event
+- `#!python3 on_process_callback_query` - will be triggered on **process** `#!python3 callback_query` event
+- `#!python3 on_post_process_callback_query` - will be triggered on **post process** `#!python3 callback_query` event
+- `#!python3 on_pre_process_shipping_query` - will be triggered on **pre process** `#!python3 shipping_query` event
+- `#!python3 on_process_shipping_query` - will be triggered on **process** `#!python3 shipping_query` event
+- `#!python3 on_post_process_shipping_query` - will be triggered on **post process** `#!python3 shipping_query` event
+- `#!python3 on_pre_process_pre_checkout_query` - will be triggered on **pre process** `#!python3 pre_checkout_query` event
+- `#!python3 on_process_pre_checkout_query` - will be triggered on **process** `#!python3 pre_checkout_query` event
+- `#!python3 on_post_process_pre_checkout_query` - will be triggered on **post process** `#!python3 pre_checkout_query` event
+- `#!python3 on_pre_process_poll` - will be triggered on **pre process** `#!python3 poll` event
+- `#!python3 on_process_poll` - will be triggered on **process** `#!python3 poll` event
+- `#!python3 on_post_process_poll` - will be triggered on **post process** `#!python3 poll` event
+- `#!python3 on_pre_process_poll_answer` - will be triggered on **pre process** `#!python3 poll_answer` event
+- `#!python3 on_process_poll_answer` - will be triggered on **process** `#!python3 poll_answer` event
+- `#!python3 on_post_process_poll_answer` - will be triggered on **post process** `#!python3 poll_answer` event

docs/dispatcher/middlewares/index.md

@@ -0,0 +1,65 @@
+# Overview
+
+**aiogram**'s provides powerful mechanism for customizing event handlers via middlewares.
+
+Middlewares in bot framework seems like Middlewares mechanism in powerful web-frameworks 
+(like [aiohttp](https://docs.aiohttp.org/en/stable/web_advanced.html#aiohttp-web-middlewares), 
+[fastapi](https://fastapi.tiangolo.com/tutorial/middleware/), 
+[Django](https://docs.djangoproject.com/en/3.0/topics/http/middleware/) or etc.) 
+with small difference - here is implemented many layers of processing 
+(named as [pipeline](#event-pipeline)).
+
+!!! info
+    Middleware is function that triggered on every event received from 
+    Telegram Bot API in many points on processing pipeline.
+
+## Base theory
+
+As many books and other literature in internet says: 
+> Middleware is reusable software that leverages patterns and frameworks to bridge 
+>the gap between the functional requirements of applications and the underlying operating systems,
+> network protocol stacks, and databases.
+
+Middleware can modify, extend or reject processing event before-, 
+on- or after- processing of that event.
+
+[![middlewares](../../assets/images/basics_middleware.png)](../../assets/images/basics_middleware.png)
+
+_(Click on image to zoom it)_
+
+## Event pipeline
+
+As described below middleware an interact with event in many stages of pipeline.
+
+Simple workflow:
+
+1. Dispatcher receive an [Update](../../api/types/update.md)
+1. Call **pre-process** update middleware in all routers tree 
+1. Filter Update over handlers
+1. Call **process** update middleware in all routers tree
+1. Router detects event type (Message, Callback query, etc.)
+1. Router triggers **pre-process** <event> middleware of specific type
+1. Pass event over [filters](../filters/index.md) to detect specific handler
+1. Call **process** <event> middleware for specific type (only when handler for this event exists)
+1. *Do magick*. Call handler (Read more [Event observers](../router.md#event-observers))
+1. Call **post-process** <event> middleware
+1. Call **post-process** update middleware in all routers tree
+1. Emit response into webhook (when it needed)
+
+### Pipeline in pictures:
+
+#### Simple pipeline
+
+[![middlewares](../../assets/images/middleware_pipeline.png)](../../assets/images/middleware_pipeline.png)
+
+_(Click on image to zoom it)_
+
+#### Nested routers pipeline
+
+[![middlewares](../../assets/images/middleware_pipeline_nested.png)](../../assets/images/middleware_pipeline_nested.png)
+
+_(Click on image to zoom it)_
+
+## Read more
+
+- [Middleware Basics](basics.md)

docs/index.md

@@ -15,11 +15,11 @@ Documentation for version 3.0 [WIP] [^1]
 
 ## Features
 
-- Asynchronous
+- Asynchronous ([asyncio docs](https://docs.python.org/3/library/asyncio.html), [PEP-492](https://www.python.org/dev/peps/pep-0492/))
 - [Supports Telegram Bot API v{!_api_version.md!}](api/index.md)
 - [Updates router](dispatcher/index.md) (Blueprints)
 - Finite State Machine
-- Middlewares
+- [Middlewares](dispatcher/middlewares/index.md)
 - [Replies into Webhook](https://core.telegram.org/bots/faq#how-can-i-make-requests-in-response-to-updates)
 
 

docs/todo.md

@@ -23,8 +23,8 @@
             - [x] ContentTypes
             - [x] Text
             - [ ] ...
-    - [ ] Middlewares
-        - [ ] Engine
+    - [x] Middlewares
+        - [x] Engine
         - [ ] Builtin middlewares
             - [ ] ...
     - [ ] Webhook
@@ -41,6 +41,7 @@
         - [x] Dispatcher
         - [x] Router
         - [x] Observers
+        - [x] Middleware
         - [ ] Filters
     - [ ] Utils
         - [x] Helper

mkdocs.yml

@@ -17,7 +17,7 @@ theme:
   logo: 'assets/images/logo.png'
 
 extra:
-  version: 3.0.0a2
+  version: 3.0.0a3
 
 plugins:
   - search
@@ -249,6 +249,9 @@ nav:
           - dispatcher/class_based_handlers/poll.md
           - dispatcher/class_based_handlers/pre_checkout_query.md
           - dispatcher/class_based_handlers/shipping_query.md
+      - Middlewares:
+          - dispatcher/middlewares/index.md
+          - dispatcher/middlewares/basics.md
   - todo.md
   - Build reports:
       - reports.md

tests/test_api/test_types/test_message.py

@@ -7,6 +7,7 @@ from aiogram.api.methods import (
     SendAnimation,
     SendAudio,
     SendContact,
+    SendDice,
     SendDocument,
     SendGame,
     SendInvoice,
@@ -26,6 +27,7 @@ from aiogram.api.types import (
     Audio,
     Chat,
     Contact,
+    Dice,
     Document,
     EncryptedCredentials,
     Game,
@@ -391,6 +393,16 @@ class TestMessage:
                 ),
                 ContentType.POLL,
             ],
+            [
+                Message(
+                    message_id=42,
+                    date=datetime.datetime.now(),
+                    chat=Chat(id=42, type="private"),
+                    dice=Dice(value=6),
+                    from_user=User(id=42, is_bot=False, first_name="Test"),
+                ),
+                ContentType.DICE,
+            ],
             [
                 Message(
                     message_id=42,
@@ -431,6 +443,7 @@ class TestMessage:
             ["", dict(text="test"), SendMessage],
             ["photo", dict(photo="photo"), SendPhoto],
             ["poll", dict(question="Q?", options=[]), SendPoll],
+            ["dice", dict(), SendDice],
             ["sticker", dict(sticker="sticker"), SendSticker],
             ["sticker", dict(sticker="sticker"), SendSticker],
             [

tests/test_dispatcher/test_middlewares/test_base.py

@@ -0,0 +1,241 @@
+import datetime
+from typing import Any, Dict, Type
+
+import pytest
+
+from aiogram.api.types import (
+    CallbackQuery,
+    Chat,
+    ChosenInlineResult,
+    InlineQuery,
+    Message,
+    Poll,
+    PollAnswer,
+    PreCheckoutQuery,
+    ShippingQuery,
+    Update,
+    User,
+)
+from aiogram.dispatcher.middlewares.base import BaseMiddleware
+from aiogram.dispatcher.middlewares.types import MiddlewareStep, UpdateType
+
+try:
+    from asynctest import CoroutineMock, patch
+except ImportError:
+    from unittest.mock import AsyncMock as CoroutineMock, patch  # type: ignore
+
+
+class MyMiddleware(BaseMiddleware):
+    async def on_pre_process_update(self, update: Update, data: Dict[str, Any]) -> Any:
+        return "update"
+
+    async def on_pre_process_message(self, message: Message, data: Dict[str, Any]) -> Any:
+        return "message"
+
+    async def on_pre_process_edited_message(
+        self, edited_message: Message, data: Dict[str, Any]
+    ) -> Any:
+        return "edited_message"
+
+    async def on_pre_process_channel_post(
+        self, channel_post: Message, data: Dict[str, Any]
+    ) -> Any:
+        return "channel_post"
+
+    async def on_pre_process_edited_channel_post(
+        self, edited_channel_post: Message, data: Dict[str, Any]
+    ) -> Any:
+        return "edited_channel_post"
+
+    async def on_pre_process_inline_query(
+        self, inline_query: InlineQuery, data: Dict[str, Any]
+    ) -> Any:
+        return "inline_query"
+
+    async def on_pre_process_chosen_inline_result(
+        self, chosen_inline_result: ChosenInlineResult, data: Dict[str, Any]
+    ) -> Any:
+        return "chosen_inline_result"
+
+    async def on_pre_process_callback_query(
+        self, callback_query: CallbackQuery, data: Dict[str, Any]
+    ) -> Any:
+        return "callback_query"
+
+    async def on_pre_process_shipping_query(
+        self, shipping_query: ShippingQuery, data: Dict[str, Any]
+    ) -> Any:
+        return "shipping_query"
+
+    async def on_pre_process_pre_checkout_query(
+        self, pre_checkout_query: PreCheckoutQuery, data: Dict[str, Any]
+    ) -> Any:
+        return "pre_checkout_query"
+
+    async def on_pre_process_poll(self, poll: Poll, data: Dict[str, Any]) -> Any:
+        return "poll"
+
+    async def on_pre_process_poll_answer(
+        self, poll_answer: PollAnswer, data: Dict[str, Any]
+    ) -> Any:
+        return "poll_answer"
+
+    async def on_process_update(self, update: Update, data: Dict[str, Any]) -> Any:
+        return "update"
+
+    async def on_process_message(self, message: Message, data: Dict[str, Any]) -> Any:
+        return "message"
+
+    async def on_process_edited_message(
+        self, edited_message: Message, data: Dict[str, Any]
+    ) -> Any:
+        return "edited_message"
+
+    async def on_process_channel_post(self, channel_post: Message, data: Dict[str, Any]) -> Any:
+        return "channel_post"
+
+    async def on_process_edited_channel_post(
+        self, edited_channel_post: Message, data: Dict[str, Any]
+    ) -> Any:
+        return "edited_channel_post"
+
+    async def on_process_inline_query(
+        self, inline_query: InlineQuery, data: Dict[str, Any]
+    ) -> Any:
+        return "inline_query"
+
+    async def on_process_chosen_inline_result(
+        self, chosen_inline_result: ChosenInlineResult, data: Dict[str, Any]
+    ) -> Any:
+        return "chosen_inline_result"
+
+    async def on_process_callback_query(
+        self, callback_query: CallbackQuery, data: Dict[str, Any]
+    ) -> Any:
+        return "callback_query"
+
+    async def on_process_shipping_query(
+        self, shipping_query: ShippingQuery, data: Dict[str, Any]
+    ) -> Any:
+        return "shipping_query"
+
+    async def on_process_pre_checkout_query(
+        self, pre_checkout_query: PreCheckoutQuery, data: Dict[str, Any]
+    ) -> Any:
+        return "pre_checkout_query"
+
+    async def on_process_poll(self, poll: Poll, data: Dict[str, Any]) -> Any:
+        return "poll"
+
+    async def on_process_poll_answer(self, poll_answer: PollAnswer, data: Dict[str, Any]) -> Any:
+        return "poll_answer"
+
+    async def on_post_process_update(
+        self, update: Update, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "update"
+
+    async def on_post_process_message(
+        self, message: Message, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "message"
+
+    async def on_post_process_edited_message(
+        self, edited_message: Message, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "edited_message"
+
+    async def on_post_process_channel_post(
+        self, channel_post: Message, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "channel_post"
+
+    async def on_post_process_edited_channel_post(
+        self, edited_channel_post: Message, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "edited_channel_post"
+
+    async def on_post_process_inline_query(
+        self, inline_query: InlineQuery, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "inline_query"
+
+    async def on_post_process_chosen_inline_result(
+        self, chosen_inline_result: ChosenInlineResult, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "chosen_inline_result"
+
+    async def on_post_process_callback_query(
+        self, callback_query: CallbackQuery, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "callback_query"
+
+    async def on_post_process_shipping_query(
+        self, shipping_query: ShippingQuery, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "shipping_query"
+
+    async def on_post_process_pre_checkout_query(
+        self, pre_checkout_query: PreCheckoutQuery, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "pre_checkout_query"
+
+    async def on_post_process_poll(self, poll: Poll, data: Dict[str, Any], result: Any) -> Any:
+        return "poll"
+
+    async def on_post_process_poll_answer(
+        self, poll_answer: PollAnswer, data: Dict[str, Any], result: Any
+    ) -> Any:
+        return "poll_answer"
+
+
+UPDATE = Update(update_id=42)
+MESSAGE = Message(message_id=42, date=datetime.datetime.now(), chat=Chat(id=42, type="private"))
+POLL_ANSWER = PollAnswer(
+    poll_id="poll", user=User(id=42, is_bot=False, first_name="Test"), option_ids=[0]
+)
+
+
+class TestBaseMiddleware:
+    @pytest.mark.asyncio
+    @pytest.mark.parametrize(
+        "middleware_cls,should_be_awaited", [[MyMiddleware, True], [BaseMiddleware, False]]
+    )
+    @pytest.mark.parametrize(
+        "step", [MiddlewareStep.PRE_PROCESS, MiddlewareStep.PROCESS, MiddlewareStep.POST_PROCESS]
+    )
+    @pytest.mark.parametrize(
+        "event_name,event",
+        [["update", UPDATE], ["message", MESSAGE], ["poll_answer", POLL_ANSWER],],
+    )
+    async def test_trigger(
+        self,
+        step: MiddlewareStep,
+        event_name: str,
+        event: UpdateType,
+        middleware_cls: Type[BaseMiddleware],
+        should_be_awaited: bool,
+    ):
+        middleware = middleware_cls()
+
+        with patch(
+            f"tests.test_dispatcher.test_middlewares.test_base."
+            f"MyMiddleware.on_{step.value}_{event_name}",
+            new_callable=CoroutineMock,
+        ) as mocked_call:
+            response = await middleware.trigger(
+                step=step, event_name=event_name, event=event, data={}
+            )
+            if should_be_awaited:
+                mocked_call.assert_awaited()
+                assert response is not None
+            else:
+                mocked_call.assert_not_awaited()
+                assert response is None
+
+    def test_not_configured(self):
+        middleware = BaseMiddleware()
+        assert not middleware.configured
+
+        with pytest.raises(RuntimeError):
+            manager = middleware.manager

tests/test_dispatcher/test_middlewares/test_manager.py

@@ -0,0 +1,82 @@
+import pytest
+
+from aiogram import Router
+from aiogram.api.types import Update
+from aiogram.dispatcher.middlewares.base import BaseMiddleware
+from aiogram.dispatcher.middlewares.manager import MiddlewareManager
+from aiogram.dispatcher.middlewares.types import MiddlewareStep
+
+try:
+    from asynctest import CoroutineMock, patch
+except ImportError:
+    from unittest.mock import AsyncMock as CoroutineMock, patch  # type: ignore
+
+
+@pytest.fixture("function")
+def router():
+    return Router()
+
+
+@pytest.fixture("function")
+def manager(router: Router):
+    return MiddlewareManager(router)
+
+
+class TestManager:
+    def test_setup(self, manager: MiddlewareManager):
+        middleware = BaseMiddleware()
+        returned = manager.setup(middleware)
+        assert returned is middleware
+        assert middleware.configured
+        assert middleware.manager is manager
+        assert middleware in manager
+
+    @pytest.mark.parametrize("obj", [object, object(), None, BaseMiddleware])
+    def test_setup_invalid_type(self, manager: MiddlewareManager, obj):
+        with pytest.raises(TypeError):
+            assert manager.setup(obj)
+
+    def test_configure_twice_different_managers(self, manager: MiddlewareManager, router: Router):
+        middleware = BaseMiddleware()
+        manager.setup(middleware)
+
+        assert middleware.configured
+
+        new_manager = MiddlewareManager(router)
+        with pytest.raises(ValueError):
+            new_manager.setup(middleware)
+        with pytest.raises(ValueError):
+            middleware.setup(new_manager)
+
+    def test_configure_twice(self, manager: MiddlewareManager):
+        middleware = BaseMiddleware()
+        manager.setup(middleware)
+
+        assert middleware.configured
+
+        with pytest.warns(RuntimeWarning, match="is already configured for this Router"):
+            manager.setup(middleware)
+
+        with pytest.warns(RuntimeWarning, match="is already configured for this Router"):
+            middleware.setup(manager)
+
+    @pytest.mark.asyncio
+    @pytest.mark.parametrize("count", range(5))
+    async def test_trigger(self, manager: MiddlewareManager, count: int):
+        for _ in range(count):
+            manager.setup(BaseMiddleware())
+
+        with patch(
+            "aiogram.dispatcher.middlewares.base.BaseMiddleware.trigger",
+            new_callable=CoroutineMock,
+        ) as mocked_call:
+            await manager.trigger(
+                step=MiddlewareStep.PROCESS,
+                event_name="update",
+                event=Update(update_id=42),
+                data={},
+                result=None,
+                reverse=True,
+            )
+
+            assert mocked_call.await_count == count

tests/test_dispatcher/test_router.py

@@ -18,6 +18,7 @@ from aiogram.api.types import (
     User,
 )
 from aiogram.dispatcher.event.observer import SkipHandler
+from aiogram.dispatcher.middlewares.base import BaseMiddleware
 from aiogram.dispatcher.router import Router
 from aiogram.utils.warnings import CodeHasNoEffect
 
@@ -407,3 +408,11 @@ class TestRouter:
 
         await router1.emit_shutdown()
         assert results == [2, 1, 2]
+
+    def test_use(self):
+        router = Router()
+
+        middleware = router.use(BaseMiddleware())
+        assert isinstance(middleware, BaseMiddleware)
+        assert middleware.configured
+        assert middleware.manager == router.middleware

tests/test_utils/test_markdown.py

@@ -2,37 +2,54 @@ from typing import Any, Callable, Optional, Tuple
 
 import pytest
 
-from aiogram.utils import markdown
+from aiogram.utils.markdown import (
+    bold,
+    code,
+    hbold,
+    hcode,
+    hide_link,
+    hitalic,
+    hlink,
+    hpre,
+    hstrikethrough,
+    hunderline,
+    italic,
+    link,
+    pre,
+    strikethrough,
+    text,
+    underline,
+)
 
 
 class TestMarkdown:
     @pytest.mark.parametrize(
         "func,args,sep,result",
         [
-            [markdown.text, ("test", "test"), " ", "test test"],
-            [markdown.text, ("test", "test"), "\n", "test\ntest"],
-            [markdown.text, ("test", "test"), None, "test test"],
-            [markdown.bold, ("test", "test"), " ", "*test test*"],
-            [markdown.hbold, ("test", "test"), " ", "<b>test test</b>"],
-            [markdown.italic, ("test", "test"), " ", "_test test_\r"],
-            [markdown.hitalic, ("test", "test"), " ", "<i>test test</i>"],
-            [markdown.code, ("test", "test"), " ", "`test test`"],
-            [markdown.hcode, ("test", "test"), " ", "<code>test test</code>"],
-            [markdown.pre, ("test", "test"), " ", "```test test```"],
-            [markdown.hpre, ("test", "test"), " ", "<pre>test test</pre>"],
-            [markdown.underline, ("test", "test"), " ", "__test test__"],
-            [markdown.hunderline, ("test", "test"), " ", "<u>test test</u>"],
-            [markdown.strikethrough, ("test", "test"), " ", "~test test~"],
-            [markdown.hstrikethrough, ("test", "test"), " ", "<s>test test</s>"],
-            [markdown.link, ("test", "https://aiogram.dev"), None, "[test](https://aiogram.dev)"],
+            [text, ("test", "test"), " ", "test test"],
+            [text, ("test", "test"), "\n", "test\ntest"],
+            [text, ("test", "test"), None, "test test"],
+            [bold, ("test", "test"), " ", "*test test*"],
+            [hbold, ("test", "test"), " ", "<b>test test</b>"],
+            [italic, ("test", "test"), " ", "_test test_\r"],
+            [hitalic, ("test", "test"), " ", "<i>test test</i>"],
+            [code, ("test", "test"), " ", "`test test`"],
+            [hcode, ("test", "test"), " ", "<code>test test</code>"],
+            [pre, ("test", "test"), " ", "```test test```"],
+            [hpre, ("test", "test"), " ", "<pre>test test</pre>"],
+            [underline, ("test", "test"), " ", "__test test__"],
+            [hunderline, ("test", "test"), " ", "<u>test test</u>"],
+            [strikethrough, ("test", "test"), " ", "~test test~"],
+            [hstrikethrough, ("test", "test"), " ", "<s>test test</s>"],
+            [link, ("test", "https://aiogram.dev"), None, "[test](https://aiogram.dev)"],
             [
-                markdown.hlink,
+                hlink,
                 ("test", "https://aiogram.dev"),
                 None,
                 '<a href="https://aiogram.dev">test</a>',
             ],
             [
-                markdown.hide_link,
+                hide_link,
                 ("https://aiogram.dev",),
                 None,
                 '<a href="https://aiogram.dev">&#8203;</a>',