Add docs for Dispatcher

aiogram/dispatcher/event/event.py

@@ -8,6 +8,19 @@ from .handler import CallbackType, HandlerObject, HandlerType
 class EventObserver:
     """
     Simple events observer
+
+    Is used for managing events is not related with Telegram (For example startup/shutdown processes)
+
+    Handlers can be registered via decorator or method
+
+    .. code-block:: python
+
+        <observer>.register(my_handler)
+
+    .. code-block:: python
+
+        @<observer>()
+        async def my_handler(*args, **kwargs): ...
     """
 
     def __init__(self) -> None:

aiogram/dispatcher/event/telegram.py

@@ -18,6 +18,9 @@ if TYPE_CHECKING:  # pragma: no cover
 class TelegramEventObserver:
     """
     Event observer for Telegram events
+
+    Here you can register handler with filters or bounded filters which can be used as keyword arguments instead of writing full references when you register new handlers.
+    This observer will stops event propagation when first handler is pass.
     """
 
     def __init__(self, router: Router, event_name: str) -> None:
@@ -153,10 +156,19 @@ class TelegramEventObserver:
         Decorator for registering inner middlewares
 
         Usage:
-        >>> @<event>.middleware()  # via decorator (variant 1)
-        >>> @<event>.middleware  # via decorator (variant 2)
-        >>> async def my_middleware(handler, event, data): ...
-        >>> <event>.middleware(middleware)  # via method
+
+        .. code-block:: python
+
+            @<event>.middleware()  # via decorator (variant 1)
+
+        .. code-block:: python
+
+            @<event>.middleware  # via decorator (variant 2)
+
+        .. code-block:: python
+
+            async def my_middleware(handler, event, data): ...
+            <event>.middleware(my_middleware)  # via method
         """
 
         def wrapper(m: MiddlewareType) -> MiddlewareType:
@@ -174,10 +186,19 @@ class TelegramEventObserver:
         Decorator for registering outer middlewares
 
         Usage:
-        >>> @<event>.outer_middleware()  # via decorator (variant 1)
-        >>> @<event>.outer_middleware  # via decorator (variant 2)
-        >>> async def my_middleware(handler, event, data): ...
-        >>> <event>.outer_middleware(my_middleware)  # via method
+
+        .. code-block:: python
+
+            @<event>.outer_middleware()  # via decorator (variant 1)
+
+        .. code-block:: python
+
+            @<event>.outer_middleware  # via decorator (variant 2)
+
+        .. code-block:: python
+
+            async def my_middleware(handler, event, data): ...
+            <event>.outer_middleware(my_middleware)  # via method
         """
 
         def wrapper(m: MiddlewareType) -> MiddlewareType:

aiogram/dispatcher/router.py

@@ -15,10 +15,22 @@ from .middlewares.error import ErrorsMiddleware
 
 class Router:
     """
-    Events router
+    Router can route update and it nested update types like messages, callback query, polls and all other event types.
+    Here is used event-observer pattern.
+
+    Event handlers can be registered in observer by two ways:
+
+    - By observer method - :obj:`router.<event_type>.register(handler, <filters, ...>)`
+    - By decorator - :obj:`@router.<event_type>(<filters, ...>)`
+
     """
 
     def __init__(self, use_builtin_filters: bool = True) -> None:
+        """
+
+        :param use_builtin_filters: `aiogram` has many builtin filters and you can controll automatic registration of this filters in factory
+        """
+
         self.use_builtin_filters = use_builtin_filters
 
         self._parent_router: Optional[Router] = None