bug: Changing `tooltip` in `before_update()` does not work immediately

[jnsh]

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• I have searched the opened issues and there are no duplicates

Describe the bug

Changing the tooltip value for a custom control in its before_update(), and calling update() for the control does not immediately change the tooltip in the UI. It is necessary to call update() for the tooltip to change in the UI.

Code sample

Code

import flet as ft

class CustomText(ft.Text):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

        self.number = 0
        self.size = 42
        self.text_align = ft.TextAlign.CENTER

    def before_update(self):
        super().before_update()
        self.number += 1
        self.value=str(self.number)
        self.tooltip=str(self.number)

def main(page: ft.Page) -> None:

    number = CustomText(width=float("inf"))
    page.add(number)
    page.add(ft.TextButton(
        text="Click to increase number",
        on_click=lambda e: number.update(),
        width=float("inf")
    ))
    page.add(ft.Text(
        value="The number and its tooltip are set as the same value, but the tooltip is always one behind :(",
        text_align=ft.TextAlign.CENTER,
        width=float("inf")
    ))

ft.app(main)

To reproduce

1. Create custom Flet control class
2. In the custom class, add before_update() function that changes self.tooltip
3. Call update() on the custom control
   -> Control's tooltip is not immediately updated, until you call update() the second time.

Expected behavior

Setting tooltip in before_update() should change it in UI immediately when update() is called, the same way it works for e.g. flet.Text.value

Screenshots / Videos

Captures

Screencast.From.2025-10-25.15-30-10.mp4

Operating System

Linux

Operating system details

Arch Linux

Flet version

0.28.3

Regression

I'm not sure / I don't know

Suggestions

No response

Logs

Additional details

No response

[ndonkoHenri]

I wont recommend to do such an operation in before_update().
You can do it this way:

class CustomText(ft.Text):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

        self.number = 0
        self.value = str(self.number)
        self.size = 42
        self.text_align = ft.TextAlign.CENTER

    def increment(self):
        self.number += 1
        self.value = str(self.number)
        self.tooltip = str(self.number)

# ---

page.add(
        ft.TextButton(
            on_click=lambda e: number.increment(),
        )
    )

[jnsh]

@ndonkoHenri Than you for the response.

I understand the example code is not practical, but it is merely intended for demonstrating the issue.

In the real world situation where this effects our project, the value displayed in the tooltip may have changed in the background, and the most practical approach to keep it up-to-date is updating it in every update().