Pydoc observer

aiogram/dispatcher/event/observer.py

@@ -1,7 +1,17 @@
 from __future__ import annotations
 
 import copy
-from typing import TYPE_CHECKING, Any, Dict, List, Type
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    AsyncGenerator,
+    Callable,
+    Dict,
+    Generator,
+    List,
+    Optional,
+    Type,
+)
 
 from pydantic import ValidationError
 
@@ -21,16 +31,12 @@ class EventObserver:
     Base events observer
     """
 
-    def __init__(self):
+    def __init__(self) -> None:
         self.handlers: List[HandlerObject] = []
 
-    def register(self, callback: HandlerType, *filters: FilterType):
+    def register(self, callback: HandlerType, *filters: FilterType) -> HandlerType:
         """
         Register callback with filters
-
-        :param callback:
-        :param filters:
-        :return:
         """
         self.handlers.append(
             HandlerObject(
@@ -39,7 +45,11 @@ class EventObserver:
         )
         return callback
 
-    async def trigger(self, *args, **kwargs):
+    async def trigger(self, *args: Any, **kwargs: Any) -> AsyncGenerator[Any, None]:
+        """
+        Propagate event to handlers.
+        Handler will be called when all its filters is pass.
+        """
         for handler in self.handlers:
             kwargs_copy = copy.copy(kwargs)
             result, data = await handler.check(*args, **kwargs)
@@ -50,8 +60,12 @@ class EventObserver:
                 except SkipHandler:
                     continue
 
-    def __call__(self, *args: FilterType):
-        def wrapper(callback: CallbackType):
+    def __call__(self, *args: FilterType) -> Callable[[CallbackType], CallbackType]:
+        """
+        Decorator for registering event handlers
+        """
+
+        def wrapper(callback: CallbackType) -> CallbackType:
             self.register(callback, *args)
             return callback
 
@@ -63,7 +77,7 @@ class TelegramEventObserver(EventObserver):
     Event observer for Telegram events
     """
 
-    def __init__(self, router: Router, event_name: str):
+    def __init__(self, router: Router, event_name: str) -> None:
         super().__init__()
 
         self.router: Router = router
@@ -71,16 +85,25 @@ class TelegramEventObserver(EventObserver):
         self.filters: List[Type[BaseFilter]] = []
 
     def bind_filter(self, bound_filter: Type[BaseFilter]) -> None:
+        """
+        Register filter class in factory
+
+        :param bound_filter:
+        """
         if not issubclass(bound_filter, BaseFilter):
             raise TypeError(
                 "bound_filter() argument 'bound_filter' must be subclass of BaseFilter"
             )
         self.filters.append(bound_filter)
 
-    def _resolve_filters_chain(self):
-        registry: List[FilterType] = []
+    def _resolve_filters_chain(self) -> Generator[Type[BaseFilter], None, None]:
+        """
+        Get all bounded filters from current observer and from the parents
+        with the same event type without duplicates
+        """
+        registry: List[Type[BaseFilter]] = []
 
-        router = self.router
+        router: Optional[Router] = self.router
         while router:
             observer = router.observers[self.event_name]
             router = router.parent_router
@@ -91,16 +114,10 @@ class TelegramEventObserver(EventObserver):
                 yield filter_
                 registry.append(filter_)
 
-    def register(self, callback: HandlerType, *filters: FilterType, **bound_filters: Any):
-        resolved_filters = self.resolve_filters(bound_filters)
-        return super().register(callback, *filters, *resolved_filters)
-
-    async def trigger(self, *args, **kwargs):
-        async for result in super(TelegramEventObserver, self).trigger(*args, **kwargs):
-            yield result
-            break
-
     def resolve_filters(self, full_config: Dict[str, Any]) -> List[BaseFilter]:
+        """
+        Resolve keyword filters via filters factory
+        """
         filters: List[BaseFilter] = []
         if not full_config:
             return filters
@@ -112,19 +129,44 @@ class TelegramEventObserver(EventObserver):
             except ValidationError:
                 continue
 
-            # Clean full config to prevent to re-initialize another filter with the same configuration
+            # Clean full config to prevent to re-initialize another filter
+            # with the same configuration
             for key in f.__fields__:
                 full_config.pop(key, None)
 
             filters.append(f)
 
         if full_config:
-            raise ValueError(f"Unknown filters: {set(full_config.keys())}")
+            raise ValueError(f"Unknown keyword filters: {set(full_config.keys())}")
 
         return filters
 
-    def __call__(self, *args: FilterType, **bound_filters):
-        def wrapper(callback: CallbackType):
+    def register(
+        self, callback: HandlerType, *filters: FilterType, **bound_filters: Any
+    ) -> HandlerType:
+        """
+        Register event handler
+        """
+        resolved_filters = self.resolve_filters(bound_filters)
+        return super().register(callback, *filters, *resolved_filters)
+
+    async def trigger(self, *args: Any, **kwargs: Any) -> AsyncGenerator[Any, None]:
+        """
+        Propagate event to handlers and stops propagation on first match.
+        Handler will be called when all its filters is pass.
+        """
+        async for result in super(TelegramEventObserver, self).trigger(*args, **kwargs):
+            yield result
+            break
+
+    def __call__(
+        self, *args: FilterType, **bound_filters: BaseFilter
+    ) -> Callable[[CallbackType], CallbackType]:
+        """
+        Decorator for registering event handlers
+        """
+
+        def wrapper(callback: CallbackType) -> CallbackType:
             self.register(callback, *args, **bound_filters)
             return callback
 

tests/test_dispatcher/test_event/test_observer.py

@@ -177,15 +177,15 @@ class TestTelegramEventObserver:
         assert any(isinstance(item, MyFilter1) for item in resolved)
 
         # Unknown filter
-        with pytest.raises(ValueError, match="Unknown filters: {'@bad'}"):
+        with pytest.raises(ValueError, match="Unknown keyword filters: {'@bad'}"):
             assert observer.resolve_filters({"@bad": "very"})
 
         # Unknown filter
-        with pytest.raises(ValueError, match="Unknown filters: {'@bad'}"):
+        with pytest.raises(ValueError, match="Unknown keyword filters: {'@bad'}"):
             assert observer.resolve_filters({"test": "ok", "@bad": "very"})
 
         # Bad argument type
-        with pytest.raises(ValueError, match="Unknown filters: {'test'}"):
+        with pytest.raises(ValueError, match="Unknown keyword filters: {'test'}"):
             assert observer.resolve_filters({"test": ...})
 
     def test_register(self):