fix(api): Fix the issue that output is not saved ...

when using `Default Value` error handling strategy

refactor draft variable saving logic into a separate method.

api/core/app/apps/workflow_app_runner.py

@@ -35,6 +35,7 @@ from core.workflow.entities.node_entities import NodeRunMetadataKey
 from core.workflow.entities.variable_pool import VariablePool
 from core.workflow.graph_engine.entities.event import (
     AgentLogEvent,
+    BaseNodeEvent,
     GraphEngineEvent,
     GraphRunFailedEvent,
     GraphRunPartialSucceededEvent,
@@ -399,17 +400,7 @@ class WorkflowBasedAppRunner(AppRunner):
                     in_loop_id=event.in_loop_id,
                 )
             )
-            with Session(bind=db.engine) as session, session.begin():
-                draft_var_saver = DraftVariableSaver(
-                    session=session,
-                    app_id=self._get_app_id(),
-                    node_id=event.node_id,
-                    node_type=event.node_type,
-                    # FIXME(QuantumGhost): rely on private state of queue_manager is not ideal.
-                    invoke_from=self.queue_manager._invoke_from,
-                    enclosing_node_id=event.in_loop_id or event.in_iteration_id or None,
-                )
-                draft_var_saver.save(outputs)
+            self._save_draft_var_for_event(event)
 
         elif isinstance(event, NodeRunFailedEvent):
             self._publish_event(
@@ -473,6 +464,8 @@ class WorkflowBasedAppRunner(AppRunner):
                     in_loop_id=event.in_loop_id,
                 )
             )
+            self._save_draft_var_for_event(event)
+
         elif isinstance(event, NodeInIterationFailedEvent):
             self._publish_event(
                 QueueNodeInIterationFailedEvent(
@@ -726,6 +719,24 @@ class WorkflowBasedAppRunner(AppRunner):
     def _publish_event(self, event: AppQueueEvent) -> None:
         self.queue_manager.publish(event, PublishFrom.APPLICATION_MANAGER)
 
+    def _save_draft_var_for_event(self, event: BaseNodeEvent):
+        run_result = event.route_node_state.node_run_result
+        if run_result is None:
+            return
+        process_data = run_result.process_data
+        outputs = run_result.outputs
+        with Session(bind=db.engine) as session, session.begin():
+            draft_var_saver = DraftVariableSaver(
+                session=session,
+                app_id=self._get_app_id(),
+                node_id=event.node_id,
+                node_type=event.node_type,
+                # FIXME(QuantumGhost): rely on private state of queue_manager is not ideal.
+                invoke_from=self.queue_manager._invoke_from,
+                enclosing_node_id=event.in_loop_id or event.in_iteration_id or None,
+            )
+            draft_var_saver.save(process_data=process_data, output=outputs)
+
 
 def _remove_first_element_from_variable_string(key: str) -> str:
     """