Fix type hints for render and on (#8429)

* type hint

* add changeset

* Use union

* type check

* lint

* add changeset

---------

Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>

.changeset/breezy-bottles-hide.md

@@ -0,0 +1,5 @@
+---
+"gradio": patch
+---
+
+feat:Fix type hints for render and on

gradio/events.py

@@ -5,7 +5,17 @@ from __future__ import annotations
 
 import dataclasses
 from functools import partial, wraps
-from typing import TYPE_CHECKING, Any, Callable, Literal, Sequence
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Callable,
+    Dict,
+    List,
+    Literal,
+    Sequence,
+    Union,
+    cast,
+)
 
 from gradio_client.documentation import document
 from jinja2 import Template
@@ -145,6 +155,32 @@ class EventListenerMethod:
     event_name: str
 
 
+if TYPE_CHECKING:
+    EventListenerCallable = Callable[
+        [
+            Union[Callable, None],
+            Union[Component, Sequence[Component], None],
+            Union[Block, Sequence[Block], Sequence[Component], Component, None],
+            Union[str, None, Literal[False]],
+            bool,
+            Literal["full", "minimal", "hidden"],
+            Union[bool, None],
+            bool,
+            int,
+            bool,
+            bool,
+            Union[Dict[str, Any], List[Dict[str, Any]], None],
+            Union[float, None],
+            Union[Literal["once", "multiple", "always_last"], None],
+            Union[str, None],
+            Union[int, None, Literal["default"]],
+            Union[str, None],
+            bool,
+        ],
+        Dependency,
+    ]
+
+
 class EventListener(str):
     def __new__(cls, event_name, *_args, **_kwargs):
         return super().__new__(cls, event_name)
@@ -331,7 +367,7 @@ class EventListener(str):
 
 
 def on(
-    triggers: Sequence[Any] | Any | None = None,
+    triggers: Sequence[EventListenerCallable] | EventListenerCallable | None = None,
     fn: Callable | None | Literal["decorator"] = "decorator",
     inputs: Component | list[Component] | set[Component] | None = None,
     outputs: Block | list[Block] | list[Component] | None = None,
@@ -376,8 +412,10 @@ def on(
     """
     from gradio.components.base import Component
 
-    if isinstance(triggers, EventListener):
-        triggers = [triggers]
+    triggers_typed = cast(EventListener, triggers)
+
+    if isinstance(triggers_typed, EventListener):
+        triggers_typed = [triggers_typed]
     if isinstance(inputs, Component):
         inputs = [inputs]
 
@@ -418,18 +456,18 @@ def on(
     if root_block is None:
         raise Exception("Cannot call on() outside of a gradio.Blocks context.")
     if triggers is None:
-        triggers = (
+        methods = (
             [EventListenerMethod(input, "change") for input in inputs]
             if inputs is not None
             else []
         )  # type: ignore
     else:
-        triggers = [
-            EventListenerMethod(t.__self__ if t.has_trigger else None, t.event_name)
-            for t in triggers
-        ]  # type: ignore
+        methods = [
+            EventListenerMethod(t.__self__ if t.has_trigger else None, t.event_name)  # type: ignore
+            for t in triggers_typed
+        ]
     dep, dep_index = root_block.set_event_trigger(
-        triggers,
+        methods,
         fn,
         inputs,
         outputs,
@@ -448,7 +486,7 @@ def on(
         show_api=show_api,
         trigger_mode=trigger_mode,
     )
-    set_cancel_events(triggers, cancels)
+    set_cancel_events(methods, cancels)
     return Dependency(None, dep.get_config(), dep_index, fn)
 
 

gradio/renderable.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Callable, Literal
+from typing import TYPE_CHECKING, Callable, List, Literal, Sequence, Union, cast
 
 from gradio_client.documentation import document
 
@@ -10,6 +10,9 @@ from gradio.context import Context, LocalContext
 from gradio.events import EventListener, EventListenerMethod
 from gradio.layouts import Column, Row
 
+if TYPE_CHECKING:
+    from gradio.events import EventListenerCallable
+
 
 class Renderable:
     def __init__(
@@ -76,8 +79,8 @@ class Renderable:
 
 @document()
 def render(
-    inputs: list[Component] | None = None,
-    triggers: list[EventListener] | EventListener | None = None,
+    inputs: list[Component] | Component | None = None,
+    triggers: Sequence[EventListenerCallable] | EventListenerCallable | None = None,
     *,
     queue: bool = True,
     trigger_mode: Literal["once", "multiple", "always_last"] | None = "always_last",
@@ -116,6 +119,8 @@ def render(
                             btn = gr.Button("Clear")
                             btn.click(lambda: gr.Textbox(value=""), None, text)
     """
+    new_triggers = cast(Union[List[EventListener], EventListener, None], triggers)
+
     if Context.root_block is None:
         raise ValueError("Reactive render must be inside a Blocks context.")
 
@@ -123,16 +128,18 @@ def render(
         [inputs] if isinstance(inputs, Component) else [] if inputs is None else inputs
     )
     _triggers: list[tuple[Block | None, str]] = []
-    if triggers is None:
+    if new_triggers is None:
         _triggers = [(Context.root_block, "load")]
         for input in inputs:
             if hasattr(input, "change"):
                 _triggers.append((input, "change"))
     else:
-        triggers = [triggers] if isinstance(triggers, EventListener) else triggers
+        new_triggers = (
+            [new_triggers] if isinstance(new_triggers, EventListener) else new_triggers
+        )
         _triggers = [
             (getattr(t, "__self__", None) if t.has_trigger else None, t.event_name)
-            for t in triggers
+            for t in new_triggers
         ]
 
     def wrapper_function(fn):