allow QueryResult.refetch to receive keep_previous_data

Author: erwinkn

examples/query.py

@@ -12,6 +12,7 @@ class UserApi(ps.State):
 	# Keyed query with keep_previous_data default True
 	@ps.query(keep_previous_data=True)
 	async def user(self):
+		print("Running user query")
 		await asyncio.sleep(0.3)
 		# Simulate API; id 13 fails to demonstrate on_error
 		if self.user_id == 13:
@@ -81,7 +82,7 @@ async def optimistic_rename():
 		ps.div(
 			ps.h2("Keyed user()", className="text-xl font-semibold mb-2"),
 			ps.p(
-				"Loading..." if s.user.is_loading else f"Data: {s.user.data}",
+				"Loading..." if s.user.data is None else f"Data: {s.user.data}",
 				className="mb-2",
 			),
 			ps.p(
@@ -90,7 +91,9 @@ async def optimistic_rename():
 			),
 			ps.div(
 				ps.button(
-					"Refetch", onClick=s.user.refetch, className="btn-primary mr-2"
+					"Refetch",
+					onClick=lambda: s.user.refetch(keep_previous_data=False),
+					className="btn-primary mr-2",
 				),
 				ps.button(
 					"Optimistic rename",

packages/pulse/python/src/pulse/query.py

@@ -44,12 +44,21 @@ def __init__(
 		self._keep_previous_data = keep_previous_data
 
 	@override
-	def push_change(self):
+	def push_change(self, keep_previous_data: bool | None = None):
 		# Synchronously clear data before scheduling the effect to run.
 		# This ensures renders see the loading state immediately, not stale data.
-		self._result._set_loading(clear_data=not self._keep_previous_data)  # pyright: ignore[reportPrivateUsage]
+		if keep_previous_data is None:
+			keep_previous_data = self._keep_previous_data
+		self._result.set_loading(clear_data=not keep_previous_data)
 		super().push_change()
 
+	def refetch(self, keep_previous_data: bool | None = None):
+		if keep_previous_data is None:
+			keep_previous_data = self._keep_previous_data
+		self.cancel()
+		self._result.set_loading(clear_data=not keep_previous_data)
+		self.run()
+
 
 class QueryResult(Generic[T]):
 	def __init__(self, initial_data: T | None = None):
@@ -63,7 +72,7 @@ def __init__(self, initial_data: T | None = None):
 		# Tracks whether at least one load cycle completed (success or error)
 		self._has_loaded: Signal[bool] = Signal(False, name="query.has_loaded")
 		# Effect driving this query (attached by QueryProperty)
-		self._effect: AsyncEffect | None = None
+		self._effect: QueryAsyncEffect | None = None
 
 	@property
 	def is_loading(self) -> bool:
@@ -89,39 +98,38 @@ def data(self) -> T | None:
 	def has_loaded(self) -> bool:
 		return self._has_loaded.read()
 
-	def attach_effect(self, effect: AsyncEffect) -> None:
+	def attach_effect(self, effect: QueryAsyncEffect) -> None:
 		self._effect = effect
 
-	def refetch(self) -> None:
+	def refetch(self, keep_previous_data: bool | None = None) -> None:
 		if self._effect is None:
 			return
-		self._effect.cancel()
-		self._effect.run()
+		self._effect.refetch(keep_previous_data=keep_previous_data)
 
 	def dispose(self) -> None:
 		if self._effect is None:
 			return
 		self._effect.dispose()
 
 	# Internal setters used by the query machinery
-	def _set_loading(self, *, clear_data: bool = False):
+	def set_loading(self, *, clear_data: bool = False):
 		# print("[QueryResult] set loading=True")
 		self._is_loading.write(True)
 		self._is_error.write(False)
 		self._error.write(None)
 		if clear_data:
 			# If there was an explicit initial value, reset to it; otherwise clear
-			self._data.write(self._initial_data)
+			self._data.write(None)
 
-	def _set_success(self, data: T):
+	def set_success(self, data: T):
 		# print(f"[QueryResult] set success data={data!r}")
 		self._data.write(data)
 		self._is_loading.write(False)
 		self._is_error.write(False)
 		self._error.write(None)
 		self._has_loaded.write(True)
 
-	def _set_error(self, err: Exception):
+	def set_error(self, err: Exception):
 		# print(f"[QueryResult] set error err={err!r}")
 		self._error.write(err)
 		self._is_loading.write(False)
@@ -140,16 +148,6 @@ def set_initial_data(self, data: T):
 		self._initial_data = data
 		self._data.write(data)
 
-	# Public helpers mirroring internal transitions
-	def set_loading(self, *, clear_data: bool = False) -> None:
-		self._set_loading(clear_data=clear_data)
-
-	def set_success(self, data: T) -> None:
-		self._set_success(data)
-
-	def set_error(self, err: Exception) -> None:
-		self._set_error(err)
-
 
 OnSuccessFn = Callable[[TState], Any] | Callable[[TState, T], Any]
 OnErrorFn = Callable[[TState], Any] | Callable[[TState, Exception], Any]
@@ -300,9 +298,6 @@ async def run_effect():
 					return None
 				inflight_key = key
 
-			# Set loading immediately; optionally clear previous data
-			result.set_loading(clear_data=not self._keep_previous_data)
-
 			try:
 				data = await bound_fetch()
 			except asyncio.CancelledError:

packages/pulse/python/src/pulse/reactive.py

@@ -457,6 +457,11 @@ def _task_name(self) -> str:
 		base = self.name or "effect"
 		return f"effect:{base}"
 
+	@override
+	def push_change(self):
+		self.cancel()
+		super().push_change()
+
 	@override
 	def _copy_kwargs(self):
 		kwargs = super()._copy_kwargs()