fix: correct user_id access logic

[dhlidongming]

This pull request addresses an issue with the user_id access logic within the CustomComponent class. Previously, there were inconsistencies in how the user_id attribute was accessed, leading to potential errors when the attribute was not set or incorrectly retrieved.
In the BaseComponent, the default setting of self._user_id to None led to inaccurate user_id retrieval:

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

Line 31 in 2f96dbb

_user_id: str | UUID | None = None

The use of hasattr(self, '_user_id') always returned True, causing _user_id to be returned even when it was None.

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

Lines 186 to 190 in 2f96dbb

	@property
	def user_id(self):
	if hasattr(self, "_user_id"):
	return self._user_id
	return self.graph.user_id

This behavior resulted in a SQL error when using the SubFlow component's run_flow method, as user_id was unexpectedly None. The fix ensures user_id is correctly handled and prevents unintended None values from causing SQL execution errors.

[ogabrielluiz]

Nice, @dhlidongming

Thank you.

LGTM

[codspeed-hq]

CodSpeed Performance Report

Merging #4595 will degrade performances by 30.94%

_{Comparing dhlidongming:fix/user-id-access-logic (c49bc14) with main (2cf3881)}

Summary

❌ 2 regressions
✅ 13 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	dhlidongming:fix/user-id-access-logic	Change
❌	test_invalid_run_with_input_type_chat	13.7 ms	16.7 ms	-17.51%
❌	test_successful_run_with_output_type_debug	161.2 ms	233.4 ms	-30.94%