add type hinting to events

reflex/components/core/clipboard.py

@@ -2,11 +2,11 @@
 
 from __future__ import annotations
 
-from typing import Dict, List, Union
+from typing import Dict, List, Tuple, Union
 
 from reflex.components.base.fragment import Fragment
 from reflex.components.tags.tag import Tag
-from reflex.event import EventChain, EventHandler
+from reflex.event import EventChain, EventHandler, identity_event
 from reflex.utils.format import format_prop, wrap
 from reflex.utils.imports import ImportVar
 from reflex.vars import get_unique_variable_name
@@ -20,7 +20,7 @@ class Clipboard(Fragment):
     targets: Var[List[str]]
 
     # Called when the user pastes data into the document. Data is a list of tuples of (mime_type, data). Binary types will be base64 encoded as a data uri.
-    on_paste: EventHandler[lambda data: [data]]
+    on_paste: EventHandler[identity_event(List[Tuple[str, str]])]
 
     # Save the original event actions for the on_paste event.
     on_paste_event_actions: Var[Dict[str, Union[bool, int]]]

reflex/components/core/debounce.py

@@ -6,7 +6,6 @@ from typing import Any, Type, Union
 
 from reflex.components.component import Component
 from reflex.constants import EventTriggers
-from reflex.event import EventHandler
 from reflex.vars import VarData
 from reflex.vars.base import Var
 
@@ -45,9 +44,6 @@ class DebounceInput(Component):
     # The element to wrap
     element: Var[Type[Component]]
 
-    # Fired when the input value changes
-    on_change: EventHandler[lambda e0: [e0.value]]
-
     @classmethod
     def create(cls, *children: Component, **props: Any) -> Component:
         """Create a DebounceInput component.
@@ -123,6 +119,8 @@ class DebounceInput(Component):
             ),
         )
 
+        print(f"{props=}")
+
         component = super().create(**props)
         component._get_style = child._get_style
         component.event_triggers.update(child.event_triggers)

reflex/components/datadisplay/dataeditor.py

@@ -3,12 +3,12 @@
 from __future__ import annotations
 
 from enum import Enum
-from typing import Any, Dict, List, Literal, Optional, Union
+from typing import Any, Dict, List, Literal, Optional, Tuple, Union
 
 from reflex.base import Base
 from reflex.components.component import Component, NoSSRComponent
 from reflex.components.literals import LiteralRowMarker
-from reflex.event import EventHandler, empty_event
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.utils import console, format, types
 from reflex.utils.imports import ImportDict, ImportVar
 from reflex.utils.serializers import serializer
@@ -223,13 +223,13 @@ class DataEditor(NoSSRComponent):
     theme: Var[Union[DataEditorTheme, Dict]]
 
     # Fired when a cell is activated.
-    on_cell_activated: EventHandler[lambda pos: [pos]]
+    on_cell_activated: EventHandler[identity_event(Tuple[int, int])]
 
     # Fired when a cell is clicked.
-    on_cell_clicked: EventHandler[lambda pos: [pos]]
+    on_cell_clicked: EventHandler[identity_event(Tuple[int, int])]
 
     # Fired when a cell is right-clicked.
-    on_cell_context_menu: EventHandler[lambda pos: [pos]]
+    on_cell_context_menu: EventHandler[identity_event(Tuple[int, int])]
 
     # Fired when a cell is edited.
     on_cell_edited: EventHandler[on_edit_spec]
@@ -244,16 +244,16 @@ class DataEditor(NoSSRComponent):
     on_group_header_renamed: EventHandler[lambda idx, val: [idx, val]]
 
     # Fired when a header is clicked.
-    on_header_clicked: EventHandler[lambda pos: [pos]]
+    on_header_clicked: EventHandler[identity_event(Tuple[int, int])]
 
     # Fired when a header is right-clicked.
-    on_header_context_menu: EventHandler[lambda pos: [pos]]
+    on_header_context_menu: EventHandler[identity_event(Tuple[int, int])]
 
     # Fired when a header menu item is clicked.
     on_header_menu_click: EventHandler[lambda col, pos: [col, pos]]
 
     # Fired when an item is hovered.
-    on_item_hovered: EventHandler[lambda pos: [pos]]
+    on_item_hovered: EventHandler[identity_event(Tuple[int, int])]
 
     # Fired when a selection is deleted.
     on_delete: EventHandler[lambda selection: [selection]]

reflex/components/el/elements/forms.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from hashlib import md5
-from typing import Any, Dict, Iterator, Set, Union
+from typing import Any, Dict, Iterator, Set, Tuple, Union
 
 from jinja2 import Environment
 
@@ -102,6 +102,15 @@ class Fieldset(Element):
     name: Var[Union[str, int, bool]]
 
 
+def on_submit_event_spec() -> Tuple[Var[Dict[str, Any]]]:
+    """Event handler spec for the on_submit event.
+
+    Returns:
+        The event handler spec.
+    """
+    return (FORM_DATA,)
+
+
 class Form(BaseHTML):
     """Display the form element."""
 
@@ -141,7 +150,7 @@ class Form(BaseHTML):
     handle_submit_unique_name: Var[str]
 
     # Fired when the form is submitted
-    on_submit: EventHandler[lambda e0: [FORM_DATA]]
+    on_submit: EventHandler[on_submit_event_spec]
 
     @classmethod
     def create(cls, *children, **props):

reflex/components/moment/moment.py

@@ -4,7 +4,7 @@ import dataclasses
 from typing import List, Optional
 
 from reflex.components.component import Component, NoSSRComponent
-from reflex.event import EventHandler
+from reflex.event import EventHandler, identity_event
 from reflex.utils.imports import ImportDict
 from reflex.vars.base import Var
 
@@ -93,7 +93,7 @@ class Moment(NoSSRComponent):
     tz: Var[str]
 
     # Fires when the date changes.
-    on_change: EventHandler[lambda date: [date]]
+    on_change: EventHandler[identity_event(str)]
 
     def add_imports(self) -> ImportDict:
         """Add the imports for the Moment component.

reflex/components/radix/primitives/accordion.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from typing import Any, List, Literal, Optional, Union
+from typing import Any, List, Literal, Optional, Tuple, Union
 
 from reflex.components.component import Component, ComponentNamespace
 from reflex.components.core.colors import color
@@ -71,6 +71,18 @@ class AccordionComponent(RadixPrimitiveComponent):
         return ["color_scheme", "variant"]
 
 
+def on_value_change(value: Var[str | List[str]]) -> Tuple[Var[str | List[str]]]:
+    """Handle the on_value_change event.
+
+    Args:
+        value: The value of the event.
+
+    Returns:
+        The value of the event.
+    """
+    return (value,)
+
+
 class AccordionRoot(AccordionComponent):
     """An accordion component."""
 
@@ -114,7 +126,7 @@ class AccordionRoot(AccordionComponent):
     _valid_children: List[str] = ["AccordionItem"]
 
     # Fired when the opened the accordions changes.
-    on_value_change: EventHandler[lambda e0: [e0]]
+    on_value_change: EventHandler[on_value_change]
 
     def _exclude_props(self) -> list[str]:
         return super()._exclude_props() + [

reflex/components/radix/primitives/drawer.py

@@ -10,7 +10,7 @@ from reflex.components.component import Component, ComponentNamespace
 from reflex.components.radix.primitives.base import RadixPrimitiveComponent
 from reflex.components.radix.themes.base import Theme
 from reflex.components.radix.themes.layout.flex import Flex
-from reflex.event import EventHandler
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.utils import console
 from reflex.vars.base import Var
 
@@ -61,7 +61,7 @@ class DrawerRoot(DrawerComponent):
     preventScrollRestoration: Var[bool]
 
     # Fires when the drawer is opened.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
 
 class DrawerTrigger(DrawerComponent):
@@ -129,19 +129,19 @@ class DrawerContent(DrawerComponent):
         return {"css": base_style}
 
     # Fired when the drawer content is opened. Deprecated.
-    on_open_auto_focus: EventHandler[lambda e0: []]
+    on_open_auto_focus: EventHandler[empty_event]
 
     # Fired when the drawer content is closed. Deprecated.
-    on_close_auto_focus: EventHandler[lambda e0: []]
+    on_close_auto_focus: EventHandler[empty_event]
 
     # Fired when the escape key is pressed. Deprecated.
-    on_escape_key_down: EventHandler[lambda e0: []]
+    on_escape_key_down: EventHandler[empty_event]
 
     # Fired when the pointer is down outside the drawer content. Deprecated.
-    on_pointer_down_outside: EventHandler[lambda e0: []]
+    on_pointer_down_outside: EventHandler[empty_event]
 
     # Fired when interacting outside the drawer content. Deprecated.
-    on_interact_outside: EventHandler[lambda e0: []]
+    on_interact_outside: EventHandler[empty_event]
 
     @classmethod
     def create(cls, *children, **props):

reflex/components/radix/primitives/slider.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from typing import Any, List, Literal
+from typing import Any, List, Literal, Tuple
 
 from reflex.components.component import Component, ComponentNamespace
 from reflex.components.radix.primitives.base import RadixPrimitiveComponentWithClassName
@@ -19,6 +19,20 @@ class SliderComponent(RadixPrimitiveComponentWithClassName):
     library = "@radix-ui/react-slider@^1.1.2"
 
 
+def on_value_event_spec(
+    value: Var[List[int]],
+) -> Tuple[Var[List[int]]]:
+    """Event handler spec for the value event.
+
+    Args:
+        value: The value of the event.
+
+    Returns:
+        The event handler spec.
+    """
+    return (value,)  # type: ignore
+
+
 class SliderRoot(SliderComponent):
     """The Slider component comtaining all slider parts."""
 
@@ -48,10 +62,10 @@ class SliderRoot(SliderComponent):
     min_steps_between_thumbs: Var[int]
 
     # Fired when the value of a thumb changes.
-    on_value_change: EventHandler[lambda e0: [e0]]
+    on_value_change: EventHandler[on_value_event_spec]
 
     # Fired when a thumb is released.
-    on_value_commit: EventHandler[lambda e0: [e0]]
+    on_value_commit: EventHandler[on_value_event_spec]
 
     def add_style(self) -> dict[str, Any] | None:
         """Add style to the component.

reflex/components/radix/themes/components/alert_dialog.py

@@ -5,7 +5,7 @@ from typing import Literal
 from reflex.components.component import ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
 from reflex.components.el import elements
-from reflex.event import EventHandler
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.vars.base import Var
 
 from ..base import RadixThemesComponent, RadixThemesTriggerComponent
@@ -22,7 +22,7 @@ class AlertDialogRoot(RadixThemesComponent):
     open: Var[bool]
 
     # Fired when the open state changes.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
 
 class AlertDialogTrigger(RadixThemesTriggerComponent):
@@ -43,13 +43,13 @@ class AlertDialogContent(elements.Div, RadixThemesComponent):
     force_mount: Var[bool]
 
     # Fired when the dialog is opened.
-    on_open_auto_focus: EventHandler[lambda e0: [e0]]
+    on_open_auto_focus: EventHandler[empty_event]
 
     # Fired when the dialog is closed.
-    on_close_auto_focus: EventHandler[lambda e0: [e0]]
+    on_close_auto_focus: EventHandler[empty_event]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: EventHandler[lambda e0: [e0]]
+    on_escape_key_down: EventHandler[empty_event]
 
 
 class AlertDialogTitle(RadixThemesComponent):

reflex/components/radix/themes/components/checkbox.py

@@ -6,7 +6,7 @@ from reflex.components.component import Component, ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
 from reflex.components.radix.themes.layout.flex import Flex
 from reflex.components.radix.themes.typography.text import Text
-from reflex.event import EventHandler
+from reflex.event import EventHandler, identity_event
 from reflex.vars.base import LiteralVar, Var
 
 from ..base import (
@@ -61,7 +61,7 @@ class Checkbox(RadixThemesComponent):
     _rename_props = {"onChange": "onCheckedChange"}
 
     # Fired when the checkbox is checked or unchecked.
-    on_change: EventHandler[lambda e0: [e0]]
+    on_change: EventHandler[identity_event(bool)]
 
 
 class HighLevelCheckbox(RadixThemesComponent):
@@ -112,7 +112,7 @@ class HighLevelCheckbox(RadixThemesComponent):
     _rename_props = {"onChange": "onCheckedChange"}
 
     # Fired when the checkbox is checked or unchecked.
-    on_change: EventHandler[lambda e0: [e0]]
+    on_change: EventHandler[identity_event(bool)]
 
     @classmethod
     def create(cls, text: Var[str] = LiteralVar.create(""), **props) -> Component:

reflex/components/radix/themes/components/context_menu.py

@@ -4,7 +4,7 @@ from typing import List, Literal
 
 from reflex.components.component import ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
-from reflex.event import EventHandler
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.vars.base import Var
 
 from ..base import (
@@ -24,7 +24,7 @@ class ContextMenuRoot(RadixThemesComponent):
     _invalid_children: List[str] = ["ContextMenuItem"]
 
     # Fired when the open state changes.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
 
 class ContextMenuTrigger(RadixThemesComponent):
@@ -64,19 +64,19 @@ class ContextMenuContent(RadixThemesComponent):
     avoid_collisions: Var[bool]
 
     # Fired when the context menu is closed.
-    on_close_auto_focus: EventHandler[lambda e0: [e0]]
+    on_close_auto_focus: EventHandler[empty_event]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: EventHandler[lambda e0: [e0]]
+    on_escape_key_down: EventHandler[empty_event]
 
     # Fired when a pointer down event happens outside the context menu.
-    on_pointer_down_outside: EventHandler[lambda e0: [e0]]
+    on_pointer_down_outside: EventHandler[empty_event]
 
     # Fired when focus moves outside the context menu.
-    on_focus_outside: EventHandler[lambda e0: [e0]]
+    on_focus_outside: EventHandler[empty_event]
 
     # Fired when interacting outside the context menu.
-    on_interact_outside: EventHandler[lambda e0: [e0]]
+    on_interact_outside: EventHandler[empty_event]
 
 
 class ContextMenuSub(RadixThemesComponent):
@@ -107,16 +107,16 @@ class ContextMenuSubContent(RadixThemesComponent):
     _valid_parents: List[str] = ["ContextMenuSub"]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: EventHandler[lambda e0: [e0]]
+    on_escape_key_down: EventHandler[empty_event]
 
     # Fired when a pointer down event happens outside the context menu.
-    on_pointer_down_outside: EventHandler[lambda e0: [e0]]
+    on_pointer_down_outside: EventHandler[empty_event]
 
     # Fired when focus moves outside the context menu.
-    on_focus_outside: EventHandler[lambda e0: [e0]]
+    on_focus_outside: EventHandler[empty_event]
 
     # Fired when interacting outside the context menu.
-    on_interact_outside: EventHandler[lambda e0: [e0]]
+    on_interact_outside: EventHandler[empty_event]
 
 
 class ContextMenuItem(RadixThemesComponent):

reflex/components/radix/themes/components/dialog.py

@@ -5,7 +5,7 @@ from typing import Literal
 from reflex.components.component import ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
 from reflex.components.el import elements
-from reflex.event import EventHandler
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.vars.base import Var
 
 from ..base import (
@@ -23,7 +23,7 @@ class DialogRoot(RadixThemesComponent):
     open: Var[bool]
 
     # Fired when the open state changes.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
 
 class DialogTrigger(RadixThemesTriggerComponent):
@@ -47,19 +47,19 @@ class DialogContent(elements.Div, RadixThemesComponent):
     size: Var[Responsive[Literal["1", "2", "3", "4"]]]
 
     # Fired when the dialog is opened.
-    on_open_auto_focus: EventHandler[lambda e0: [e0]]
+    on_open_auto_focus: EventHandler[empty_event]
 
     # Fired when the dialog is closed.
-    on_close_auto_focus: EventHandler[lambda e0: [e0]]
+    on_close_auto_focus: EventHandler[empty_event]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: EventHandler[lambda e0: [e0]]
+    on_escape_key_down: EventHandler[empty_event]
 
     # Fired when the pointer is down outside the dialog.
-    on_pointer_down_outside: EventHandler[lambda e0: [e0]]
+    on_pointer_down_outside: EventHandler[empty_event]
 
     # Fired when the pointer interacts outside the dialog.
-    on_interact_outside: EventHandler[lambda e0: [e0]]
+    on_interact_outside: EventHandler[empty_event]
 
 
 class DialogDescription(RadixThemesComponent):

reflex/components/radix/themes/components/dropdown_menu.py

@@ -4,7 +4,7 @@ from typing import Dict, List, Literal, Union
 
 from reflex.components.component import ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
-from reflex.event import EventHandler
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.vars.base import Var
 
 from ..base import (
@@ -50,7 +50,7 @@ class DropdownMenuRoot(RadixThemesComponent):
     _invalid_children: List[str] = ["DropdownMenuItem"]
 
     # Fired when the open state changes.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
 
 class DropdownMenuTrigger(RadixThemesTriggerComponent):
@@ -120,19 +120,19 @@ class DropdownMenuContent(RadixThemesComponent):
     hide_when_detached: Var[bool]
 
     # Fired when the dialog is closed.
-    on_close_auto_focus: EventHandler[lambda e0: [e0]]
+    on_close_auto_focus: EventHandler[empty_event]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: EventHandler[lambda e0: [e0]]
+    on_escape_key_down: EventHandler[empty_event]
 
     # Fired when the pointer is down outside the dialog.
-    on_pointer_down_outside: EventHandler[lambda e0: [e0]]
+    on_pointer_down_outside: EventHandler[empty_event]
 
     # Fired when focus moves outside the dialog.
-    on_focus_outside: EventHandler[lambda e0: [e0]]
+    on_focus_outside: EventHandler[empty_event]
 
     # Fired when the pointer interacts outside the dialog.
-    on_interact_outside: EventHandler[lambda e0: [e0]]
+    on_interact_outside: EventHandler[empty_event]
 
 
 class DropdownMenuSubTrigger(RadixThemesTriggerComponent):
@@ -164,7 +164,7 @@ class DropdownMenuSub(RadixThemesComponent):
     default_open: Var[bool]
 
     # Fired when the open state changes.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
 
 class DropdownMenuSubContent(RadixThemesComponent):
@@ -205,16 +205,16 @@ class DropdownMenuSubContent(RadixThemesComponent):
     _valid_parents: List[str] = ["DropdownMenuSub"]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: EventHandler[lambda e0: [e0]]
+    on_escape_key_down: EventHandler[empty_event]
 
     # Fired when the pointer is down outside the dialog.
-    on_pointer_down_outside: EventHandler[lambda e0: [e0]]
+    on_pointer_down_outside: EventHandler[empty_event]
 
     # Fired when focus moves outside the dialog.
-    on_focus_outside: EventHandler[lambda e0: [e0]]
+    on_focus_outside: EventHandler[empty_event]
 
     # Fired when the pointer interacts outside the dialog.
-    on_interact_outside: EventHandler[lambda e0: [e0]]
+    on_interact_outside: EventHandler[empty_event]
 
 
 class DropdownMenuItem(RadixThemesComponent):
@@ -240,7 +240,7 @@ class DropdownMenuItem(RadixThemesComponent):
     _valid_parents: List[str] = ["DropdownMenuContent", "DropdownMenuSubContent"]
 
     # Fired when the item is selected.
-    on_select: EventHandler[lambda e0: []]
+    on_select: EventHandler[empty_event]
 
 
 class DropdownMenuSeparator(RadixThemesComponent):

reflex/components/radix/themes/components/hover_card.py

@@ -5,7 +5,7 @@ from typing import Literal
 from reflex.components.component import ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
 from reflex.components.el import elements
-from reflex.event import EventHandler
+from reflex.event import EventHandler, identity_event
 from reflex.vars.base import Var
 
 from ..base import (
@@ -32,7 +32,7 @@ class HoverCardRoot(RadixThemesComponent):
     close_delay: Var[int]
 
     # Fired when the open state changes.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
 
 class HoverCardTrigger(RadixThemesTriggerComponent):

reflex/components/radix/themes/components/popover.py

@@ -5,7 +5,7 @@ from typing import Literal
 from reflex.components.component import ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
 from reflex.components.el import elements
-from reflex.event import EventHandler
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.vars.base import Var
 
 from ..base import (
@@ -26,7 +26,7 @@ class PopoverRoot(RadixThemesComponent):
     modal: Var[bool]
 
     # Fired when the open state changes.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
 
 class PopoverTrigger(RadixThemesTriggerComponent):
@@ -59,22 +59,22 @@ class PopoverContent(elements.Div, RadixThemesComponent):
     avoid_collisions: Var[bool]
 
     # Fired when the dialog is opened.
-    on_open_auto_focus: EventHandler[lambda e0: [e0]]
+    on_open_auto_focus: EventHandler[empty_event]
 
     # Fired when the dialog is closed.
-    on_close_auto_focus: EventHandler[lambda e0: [e0]]
+    on_close_auto_focus: EventHandler[empty_event]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: EventHandler[lambda e0: [e0]]
+    on_escape_key_down: EventHandler[empty_event]
 
     # Fired when the pointer is down outside the dialog.
-    on_pointer_down_outside: EventHandler[lambda e0: [e0]]
+    on_pointer_down_outside: EventHandler[empty_event]
 
     # Fired when focus moves outside the dialog.
-    on_focus_outside: EventHandler[lambda e0: [e0]]
+    on_focus_outside: EventHandler[empty_event]
 
     # Fired when the pointer interacts outside the dialog.
-    on_interact_outside: EventHandler[lambda e0: [e0]]
+    on_interact_outside: EventHandler[empty_event]
 
 
 class PopoverClose(RadixThemesTriggerComponent):

reflex/components/radix/themes/components/radio_cards.py

@@ -4,7 +4,7 @@ from types import SimpleNamespace
 from typing import Literal, Union
 
 from reflex.components.core.breakpoints import Responsive
-from reflex.event import EventHandler
+from reflex.event import EventHandler, identity_event
 from reflex.vars.base import Var
 
 from ..base import LiteralAccentColor, RadixThemesComponent
@@ -65,7 +65,7 @@ class RadioCardsRoot(RadixThemesComponent):
     loop: Var[bool]
 
     # Event handler called when the value changes.
-    on_value_change: EventHandler[lambda e0: [e0]]
+    on_value_change: EventHandler[identity_event(str)]
 
 
 class RadioCardsItem(RadixThemesComponent):

reflex/components/radix/themes/components/radio_group.py

@@ -9,7 +9,7 @@ from reflex.components.component import Component, ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
 from reflex.components.radix.themes.layout.flex import Flex
 from reflex.components.radix.themes.typography.text import Text
-from reflex.event import EventHandler
+from reflex.event import EventHandler, identity_event
 from reflex.utils import types
 from reflex.vars.base import LiteralVar, Var
 from reflex.vars.sequence import StringVar
@@ -59,7 +59,7 @@ class RadioGroupRoot(RadixThemesComponent):
     _rename_props = {"onChange": "onValueChange"}
 
     # Fired when the value of the radio group changes.
-    on_change: EventHandler[lambda e0: [e0]]
+    on_change: EventHandler[identity_event(str)]
 
 
 class RadioGroupItem(RadixThemesComponent):

reflex/components/radix/themes/components/segmented_control.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from types import SimpleNamespace
-from typing import List, Literal, Union
+from typing import List, Literal, Tuple, Union
 
 from reflex.components.core.breakpoints import Responsive
 from reflex.event import EventHandler
@@ -12,6 +12,18 @@ from reflex.vars.base import Var
 from ..base import LiteralAccentColor, RadixThemesComponent
 
 
+def on_value_change(value: Var[str | List[str]]) -> Tuple[Var[str | List[str]]]:
+    """Handle the on_value_change event.
+
+    Args:
+        value: The value of the event.
+
+    Returns:
+        The value of the event.
+    """
+    return (value,)
+
+
 class SegmentedControlRoot(RadixThemesComponent):
     """Root element for a SegmentedControl component."""
 
@@ -39,7 +51,7 @@ class SegmentedControlRoot(RadixThemesComponent):
     value: Var[Union[str, List[str]]]
 
     # Handles the `onChange` event for the SegmentedControl component.
-    on_change: EventHandler[lambda e0: [e0]]
+    on_change: EventHandler[on_value_change]
 
     _rename_props = {"onChange": "onValueChange"}
 

reflex/components/radix/themes/components/select.py

@@ -5,6 +5,7 @@ from typing import List, Literal, Union
 import reflex as rx
 from reflex.components.component import Component, ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
+from reflex.event import empty_event, identity_event
 from reflex.vars.base import Var
 
 from ..base import (
@@ -47,10 +48,10 @@ class SelectRoot(RadixThemesComponent):
     _rename_props = {"onChange": "onValueChange"}
 
     # Fired when the value of the select changes.
-    on_change: rx.EventHandler[lambda e0: [e0]]
+    on_change: rx.EventHandler[identity_event(str)]
 
     # Fired when the select is opened or closed.
-    on_open_change: rx.EventHandler[lambda e0: [e0]]
+    on_open_change: rx.EventHandler[identity_event(bool)]
 
 
 class SelectTrigger(RadixThemesComponent):
@@ -103,13 +104,13 @@ class SelectContent(RadixThemesComponent):
     align_offset: Var[int]
 
     # Fired when the select content is closed.
-    on_close_auto_focus: rx.EventHandler[lambda e0: [e0]]
+    on_close_auto_focus: rx.EventHandler[empty_event]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: rx.EventHandler[lambda e0: [e0]]
+    on_escape_key_down: rx.EventHandler[empty_event]
 
     # Fired when a pointer down event happens outside the select content.
-    on_pointer_down_outside: rx.EventHandler[lambda e0: [e0]]
+    on_pointer_down_outside: rx.EventHandler[empty_event]
 
 
 class SelectGroup(RadixThemesComponent):

reflex/components/radix/themes/components/slider.py

@@ -1,6 +1,6 @@
 """Interactive components provided by @radix-ui/themes."""
 
-from typing import List, Literal, Optional, Union
+from typing import List, Literal, Optional, Tuple, Union
 
 from reflex.components.component import Component
 from reflex.components.core.breakpoints import Responsive
@@ -13,6 +13,20 @@ from ..base import (
 )
 
 
+def on_value_event_spec(
+    value: Var[List[int | float]],
+) -> Tuple[Var[List[int | float]]]:
+    """Event handler spec for the value event.
+
+    Args:
+        value: The value of the event.
+
+    Returns:
+        The event handler spec.
+    """
+    return (value,)  # type: ignore
+
+
 class Slider(RadixThemesComponent):
     """Provides user selection from a range of values."""
 
@@ -64,10 +78,10 @@ class Slider(RadixThemesComponent):
     _rename_props = {"onChange": "onValueChange"}
 
     # Fired when the value of the slider changes.
-    on_change: EventHandler[lambda e0: [e0]]
+    on_change: EventHandler[on_value_event_spec]
 
     # Fired when a thumb is released after being dragged.
-    on_value_commit: EventHandler[lambda e0: [e0]]
+    on_value_commit: EventHandler[on_value_event_spec]
 
     @classmethod
     def create(

reflex/components/radix/themes/components/switch.py

@@ -3,7 +3,7 @@
 from typing import Literal
 
 from reflex.components.core.breakpoints import Responsive
-from reflex.event import EventHandler
+from reflex.event import EventHandler, identity_event
 from reflex.vars.base import Var
 
 from ..base import (
@@ -59,7 +59,7 @@ class Switch(RadixThemesComponent):
     _rename_props = {"onChange": "onCheckedChange"}
 
     # Fired when the value of the switch changes
-    on_change: EventHandler[lambda checked: [checked]]
+    on_change: EventHandler[identity_event(bool)]
 
 
 switch = Switch.create

reflex/components/radix/themes/components/tabs.py

@@ -7,7 +7,7 @@ from typing import Any, Dict, List, Literal
 from reflex.components.component import Component, ComponentNamespace
 from reflex.components.core.breakpoints import Responsive
 from reflex.components.core.colors import color
-from reflex.event import EventHandler
+from reflex.event import EventHandler, identity_event
 from reflex.vars.base import Var
 
 from ..base import (
@@ -42,7 +42,7 @@ class TabsRoot(RadixThemesComponent):
     _rename_props = {"onChange": "onValueChange"}
 
     # Fired when the value of the tabs changes.
-    on_change: EventHandler[lambda e0: [e0]]
+    on_change: EventHandler[identity_event(str)]
 
     def add_style(self) -> Dict[str, Any] | None:
         """Add style for the component.

reflex/components/radix/themes/components/tooltip.py

@@ -3,7 +3,7 @@
 from typing import Dict, Literal, Union
 
 from reflex.components.component import Component
-from reflex.event import EventHandler
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.utils import format
 from reflex.vars.base import Var
 
@@ -85,13 +85,13 @@ class Tooltip(RadixThemesComponent):
     aria_label: Var[str]
 
     # Fired when the open state changes.
-    on_open_change: EventHandler[lambda e0: [e0]]
+    on_open_change: EventHandler[identity_event(bool)]
 
     # Fired when the escape key is pressed.
-    on_escape_key_down: EventHandler[lambda e0: []]
+    on_escape_key_down: EventHandler[empty_event]
 
     # Fired when the pointer is down outside the tooltip.
-    on_pointer_down_outside: EventHandler[lambda e0: []]
+    on_pointer_down_outside: EventHandler[empty_event]
 
     @classmethod
     def create(cls, *children, **props) -> Component:

reflex/components/react_player/react_player.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from reflex.components.component import NoSSRComponent
-from reflex.event import EventHandler, empty_event
+from reflex.event import EventHandler, empty_event, identity_event
 from reflex.vars.base import Var
 
 
@@ -58,7 +58,7 @@ class ReactPlayer(NoSSRComponent):
     on_progress: EventHandler[lambda progress: [progress]]
 
     # Callback containing duration of the media, in seconds.
-    on_duration: EventHandler[lambda seconds: [seconds]]
+    on_duration: EventHandler[identity_event(float)]
 
     # Called when media is paused.
     on_pause: EventHandler[empty_event]
@@ -70,13 +70,13 @@ class ReactPlayer(NoSSRComponent):
     on_buffer_end: EventHandler[empty_event]
 
     # Called when media seeks with seconds parameter.
-    on_seek: EventHandler[lambda seconds: [seconds]]
+    on_seek: EventHandler[identity_event(float)]
 
     # Called when playback rate of the player changed. Only supported by YouTube, Vimeo (if enabled), Wistia, and file paths.
-    on_playback_rate_change: EventHandler[lambda e0: []]
+    on_playback_rate_change: EventHandler[empty_event]
 
     # Called when playback quality of the player changed. Only supported by YouTube (if enabled).
-    on_playback_quality_change: EventHandler[lambda e0: []]
+    on_playback_quality_change: EventHandler[empty_event]
 
     # Called when media finishes playing. Does not fire when loop is set to true.
     on_ended: EventHandler[empty_event]

reflex/event.py

@@ -17,6 +17,7 @@ from typing import (
     Optional,
     Tuple,
     Type,
+    TypeVar,
     Union,
     get_type_hints,
 )
@@ -458,6 +459,31 @@ def empty_event() -> Tuple[()]:
     return tuple()  # type: ignore
 
 
+T = TypeVar("T")
+
+
+def identity_event(event_type: Type[T]) -> Callable[[Var[T]], Tuple[Var[T]]]:
+    """A helper function that returns the input event as output."""
+
+    def inner(ev: Var[T]) -> Tuple[Var[T]]:
+        return (ev,)
+
+    inner.__signature__ = inspect.signature(inner).replace(  # type: ignore
+        parameters=[
+            inspect.Parameter(
+                "ev",
+                kind=inspect.Parameter.POSITIONAL_OR_KEYWORD,
+                annotation=Var[event_type],
+            )
+        ],
+        return_annotation=Tuple[Var[event_type]],
+    )
+    inner.__annotations__["ev"] = Var[event_type]
+    inner.__annotations__["return"] = Tuple[Var[event_type]]
+
+    return inner
+
+
 @dataclasses.dataclass(
     init=True,
     frozen=True,

reflex/utils/types.py

@@ -18,6 +18,7 @@ from typing import (
     List,
     Literal,
     Optional,
+    Sequence,
     Tuple,
     Type,
     Union,
@@ -102,14 +103,14 @@ if TYPE_CHECKING:
 
     # ArgsSpec = Callable[[Var], list[Var]]
     ArgsSpec = (
-        Callable[[], List[Var]]
+        Callable[[], Sequence[Var]]
-        | Callable[[Var], List[Var]]
+        | Callable[[Var], Sequence[Var]]
-        | Callable[[Var, Var], List[Var]]
+        | Callable[[Var, Var], Sequence[Var]]
-        | Callable[[Var, Var, Var], List[Var]]
+        | Callable[[Var, Var, Var], Sequence[Var]]
-        | Callable[[Var, Var, Var, Var], List[Var]]
+        | Callable[[Var, Var, Var, Var], Sequence[Var]]
-        | Callable[[Var, Var, Var, Var, Var], List[Var]]
+        | Callable[[Var, Var, Var, Var, Var], Sequence[Var]]
-        | Callable[[Var, Var, Var, Var, Var, Var], List[Var]]
+        | Callable[[Var, Var, Var, Var, Var, Var], Sequence[Var]]
-        | Callable[[Var, Var, Var, Var, Var, Var, Var], List[Var]]
+        | Callable[[Var, Var, Var, Var, Var, Var, Var], Sequence[Var]]
     )
 else:
     ArgsSpec = Callable[..., List[Any]]

tests/units/components/test_component.py

@@ -1794,7 +1794,7 @@ def test_custom_component_declare_event_handlers_in_fields():
     class TestComponent(Component):
         on_a: EventHandler[lambda e0: [e0]]
         on_b: EventHandler[input_event]
-        on_c: EventHandler[lambda e0: []]
+        on_c: EventHandler[empty_event]
         on_d: EventHandler[empty_event]
         on_e: EventHandler
         on_f: EventHandler[lambda a, b, c: [c, b, a]]

tests/units/components/test_component_future_annotations.py

@@ -26,7 +26,7 @@ def test_custom_component_declare_event_handlers_in_fields():
     class TestComponent(Component):
         on_a: EventHandler[lambda e0: [e0]]
         on_b: EventHandler[input_event]
-        on_c: EventHandler[lambda e0: []]
+        on_c: EventHandler[empty_event]
         on_d: EventHandler[empty_event]
 
     custom_component = ReferenceComponent.create()