Add tasks to set to prevent garbage collection

Author: Archmonger

src/reactpy_django/hooks.py

@@ -126,6 +126,7 @@ def use_query(
     loading, set_loading = use_state(True)
     error, set_error = use_state(cast(Union[Exception, None], None))
     query_ref = use_ref(query)
+    async_task_refs = use_ref(set())
     kwargs = kwargs or {}
     postprocessor_kwargs = postprocessor_kwargs or {}
 
@@ -174,7 +175,11 @@ def schedule_query() -> None:
         set_should_execute(False)
 
         # Execute the query in the background
-        asyncio.create_task(execute_query())
+        task = asyncio.create_task(execute_query())
+
+        # Add the task to a set to prevent it from being garbage collected
+        async_task_refs.current.add(task)
+        task.add_done_callback(async_task_refs.current.remove)
 
     @use_callback
     def refetch() -> None:
@@ -229,6 +234,7 @@ def use_mutation(
 
     loading, set_loading = use_state(False)
     error, set_error = use_state(cast(Union[Exception, None], None))
+    async_task_refs = use_ref(set())
 
     # The main "running" function for `use_mutation`
     async def execute_mutation(exec_args, exec_kwargs) -> None:
@@ -268,7 +274,11 @@ def schedule_mutation(*exec_args: FuncParams.args, **exec_kwargs: FuncParams.kwa
         set_loading(True)
 
         # Execute the mutation in the background
-        asyncio.ensure_future(execute_mutation(exec_args=exec_args, exec_kwargs=exec_kwargs))
+        task = asyncio.ensure_future(execute_mutation(exec_args=exec_args, exec_kwargs=exec_kwargs))
+
+        # Add the task to a set to prevent it from being garbage collected
+        async_task_refs.current.add(task)
+        task.add_done_callback(async_task_refs.current.remove)
 
     # Used when the user has told us to reset this mutation
     @use_callback

src/reactpy_django/pyscript/layout_handler.py

@@ -20,6 +20,7 @@ class ReactPyLayoutHandler:
 
     def __init__(self, uuid):
         self.uuid = uuid
+        self.running_tasks = set()
 
     @staticmethod
     def update_model(update, root_model):
@@ -74,14 +75,17 @@ def build_element_tree(self, layout, parent, model):
             msg = f"Unknown model type: {type(model)}"
             raise TypeError(msg)
 
-    @staticmethod
-    def create_event_handler(layout, element, event_name, event_handler_model):
+    def create_event_handler(self, layout, element, event_name, event_handler_model):
         """Create an event handler for an element. This function is used as an
         adapter between ReactPy and browser events."""
         target = event_handler_model["target"]
 
         def event_handler(*args):
-            asyncio.create_task(layout.deliver({"type": "layout-event", "target": target, "data": args}))
+            task = asyncio.create_task(layout.deliver({"type": "layout-event", "target": target, "data": args}))
+
+            # Add the task to a set to prevent it from being garbage collected
+            self.running_tasks.add(task)
+            task.add_done_callback(self.running_tasks.remove)
 
         event_name = event_name.lstrip("on_").lower().replace("_", "")
         add_event_listener(element, event_name, event_handler)