fix: correct user_id access logic (langflow-ai#4595)

fix: correct user_id access logic.

src/backend/base/langflow/custom/custom_component/custom_component.py

@@ -185,7 +185,7 @@ def graph(self):
 
     @property
     def user_id(self):
-        if hasattr(self, "_user_id"):
+        if hasattr(self, "_user_id") and self._user_id:
             return self._user_id
         return self.graph.user_id
 
@@ -477,7 +477,7 @@ async def load_flow(self, flow_id: str, tweaks: dict | None = None) -> Graph:
         if not self.user_id:
             msg = "Session is invalid"
             raise ValueError(msg)
-        return await load_flow(user_id=str(self._user_id), flow_id=flow_id, tweaks=tweaks)
+        return await load_flow(user_id=str(self.user_id), flow_id=flow_id, tweaks=tweaks)
 
     async def run_flow(
         self,
@@ -493,7 +493,7 @@ async def run_flow(
             flow_id=flow_id,
             flow_name=flow_name,
             tweaks=tweaks,
-            user_id=str(self._user_id),
+            user_id=str(self.user_id),
             run_id=self.graph.run_id,
         )
 
@@ -502,7 +502,7 @@ def list_flows(self) -> list[Data]:
             msg = "Session is invalid"
             raise ValueError(msg)
         try:
-            return list_flows(user_id=str(self._user_id))
+            return list_flows(user_id=str(self.user_id))
         except Exception as e:
             msg = f"Error listing flows: {e}"
             raise ValueError(msg) from e