Fix cancel with manager from parameter.

Author: T4rk1n

dash/_callback.py

@@ -183,6 +183,7 @@ def callback(
         *_args,
         **_kwargs,
         long=long_spec,
+        manager=manager,
     )
 
 
@@ -220,6 +221,7 @@ def insert_callback(
     inputs_state_indices,
     prevent_initial_call,
     long=None,
+    manager=None,
 ):
     if prevent_initial_call is None:
         prevent_initial_call = config_prevent_initial_callbacks
@@ -251,6 +253,7 @@ def insert_callback(
         "long": long,
         "output": output,
         "raw_inputs": inputs,
+        "manager": manager,
     }
     callback_list.append(callback_spec)
 
@@ -278,6 +281,7 @@ def register_callback(  # pylint: disable=R0914
         multi = True
 
     long = _kwargs.get("long")
+    manager = _kwargs.get("manager")
 
     output_indices = make_grouping_by_index(output, list(range(grouping_len(output))))
     callback_id = insert_callback(
@@ -291,6 +295,7 @@ def register_callback(  # pylint: disable=R0914
         inputs_state_indices,
         prevent_initial_call,
         long=long,
+        manager=manager,
     )
 
     # pylint: disable=too-many-locals

dash/dash.py

@@ -1194,9 +1194,6 @@ def dispatch(self):
             input_values
         ) = inputs_to_dict(inputs)
         g.state_values = inputs_to_dict(state)  # pylint: disable=assigning-non-slot
-        g.background_callback_manager = (
-            self._background_manager
-        )  # pylint: disable=E0237
         changed_props = body.get("changedPropIds", [])
         g.triggered_inputs = [  # pylint: disable=assigning-non-slot
             {"prop_id": x, "value": input_values.get(x)} for x in changed_props
@@ -1211,7 +1208,9 @@ def dispatch(self):
         try:
             cb = self.callback_map[output]
             func = cb["callback"]
-
+            g.background_callback_manager = (
+                cb.get("manager") or self._background_manager
+            )
             g.ignore_register_page = cb.get("long", False)
 
             # Add args_grouping
@@ -1316,21 +1315,26 @@ def _setup_server(self):
 
         _validate.validate_long_callbacks(self.callback_map)
 
-        cancels = set()
+        cancels = {}
 
         for callback in self.callback_map.values():
-            cancel = callback.get("long", {}).pop("cancel_inputs")
+            long = callback.get("long")
+            if not long:
+                continue
+            cancel = long.pop("cancel_inputs")
             if cancel:
-                cancels.update(cancel)
+                for c in cancel:
+                    cancels[c] = long.get("manager")
 
         if cancels:
-            for cancel_input in cancels:
+            for cancel_input, manager in cancels.items():
 
                 # pylint: disable=cell-var-from-loop
                 @self.callback(
                     Output(cancel_input.component_id, "id"),
                     cancel_input,
                     prevent_initial_call=True,
+                    manager=manager,
                 )
                 def cancel_call(*_):
                     job_ids = flask.request.args.getlist("cancelJob")