ui.refreshable updating the wrong element

[falkoschindler]

Description

This observation originates from a StackOverflow question: https://stackoverflow.com/questions/76763206/is-it-possible-to-use-widgets-in-nicegui-python

The following code creates two refreshable buttons, each of which refreshes itself and notifies the user about it. But independent of which button is clicked, it always refreshes button B.

class Test:

    def __init__(self, name):
        self.name = name
        self.ui()

    @ui.refreshable
    def ui(self):
        ui.notify(f'Refreshing {self.name}')
        ui.button(self.name, on_click=self.ui.refresh)

Test('A')
Test('B')

The problem can be avoided by replacing

on_click=self.ui.refresh

with

on_click=lambda: self.ui.refresh()

But what is the reason for this mixup, and how to fix it?

[falkoschindler]

I think I understand:

self.ui is static. By overriding the __get__ method, we keep track of the instance that is supposed to be used for the refresh() call.

But if we set the click handler directly like on_click=self.ui.refresh, the __get__ method isn't called when clicking the button and the last instance is used.

If we wrap the click handler in a lambda function like on_click=lambda: self.ui.refresh(), the __get__ method is called as part of the lambda function and correct instance is set before executing the refresh function.

I just don't know how to fix this bug.

[falkoschindler]

I found something:

    def __getattribute__(self, __name: str) -> Any:
        if __name == 'refresh':
            def refresh(instance=self.instance, *args: Any, **kwargs: Any) -> None:
                self.instance = instance
                object.__getattribute__(self, __name)(*args, **kwargs)
            return refresh
        return object.__getattribute__(self, __name)

This fixes the bug, but is still work in progress.