Isolated control error

[MasterA5]

Question

When trying to migrate this widget to the new logic of version 0.80.0, I get the error shown below.

Code sample

from dataclasses import field
from typing import List, Union
from flet import *
import asyncio

class AnimatedTextBubble(Container):
    def __init__(
        self, 
        texts: Union[str, List[str]] = field(default_factory=Union),
        speed: Union[int, float] = 10,
        pause: Union[int, float] = 0.0,
        bgcolor: ColorValue = Colors.GREY_900,
        border_radius: Union[int, BorderRadius] = 20,
        markdown_code_theme: MarkdownCodeTheme = MarkdownCodeTheme.ATOM_ONE_DARK,
        markdown_extension_set: MarkdownExtensionSet = MarkdownExtensionSet.GITHUB_WEB,
        border: Border | None = None
    ):
        super().__init__()
        self._running = False
        self.adaptive = True
        self.expand = True
        self.expand_loose = True
        self.padding = 10
        self.ink = True
        self.clipboard = Clipboard()
        self.border = border
        self.markdown_code_theme = markdown_code_theme
        self.markdown_extension_set = markdown_extension_set
        self.border_radius = border_radius
        self.bgcolor = bgcolor
        self.pause = pause
        self.speed = speed
        self.texts = texts

        self.on_long_press = self._copy_to_clipboard

        self.message_column = Column(spacing=2, tight=False)
        self.content = self.message_column

    def is_isolated(self):
        return True

    async def _copy_to_clipboard(self, e):
        full_text = "\n".join(self.texts)

        clean_text = (
            full_text.replace("#", "")
            .replace("*", "")
            .replace("`", "")
            .strip()
        )

        await self.clipboard.set(clean_text)

        sb = SnackBar(
            content=Text("✅ Copied to clipboard", color=Colors.WHITE),
            bgcolor=self.bgcolor,
        )

        self.page.show_dialog(sb)
        self.page.update()

    def did_mount(self):
        self._running = True
        self.page.run_task(self._type_loop)
        return super().did_mount()

    def will_unmount(self):
        self._running = False
        return super().will_unmount()

    async def _type_text(self, full_text: str):
        partial_text = ""
        md = Markdown(
            value="",
            selectable=True,
            extension_set=self.markdown_extension_set,
            code_theme=self.markdown_code_theme,
            on_tap_link=lambda e: self.page.launch_url(e.data),
        )
        self.message_column.controls.append(md)

        for ch in full_text:
            partial_text += ch
            md.value = partial_text
            self.update()
            await asyncio.sleep(1 / self.speed)
        self.update()

        if self.pause > 0:
            await asyncio.sleep(self.pause)

    async def _type_loop(self):
        for text in self.texts:
            if not self._running:
                break
            await self._type_text(text)

Error message

exception calling callback for <Future at 0x2474e9d0e10 state=finished raised RuntimeError>
Traceback (most recent call last):
  File "C:\Users\Aguss\AppData\Local\Programs\Python\Python313\Lib\concurrent\futures\_base.py", line 340, in _invoke_callbacks
    callback(self)
    ~~~~~~~~^^^^^^
  File "C:\Users\Aguss\Desktop\flet-app-test\venv\Lib\site-packages\flet\controls\page.py", line 500, in _on_completion        
    raise exception
  File "C:\Users\Aguss\Desktop\flet-app-test\src\tttttt.py", line 97, in _type_loop
    await self._type_text(text)
  File "C:\Users\Aguss\Desktop\flet-app-test\src\tttttt.py", line 86, in _type_text
    self.update()
    ~~~~~~~~~~~^^
  File "C:\Users\Aguss\Desktop\flet-app-test\venv\Lib\site-packages\flet\controls\base_control.py", line 253, in update        
    raise RuntimeError("Frozen control cannot be updated.")
RuntimeError: Frozen control cannot be updated.

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• I have searched for answers to my question both in the issues and in previous discussions.

[FeodorFitsner]

Can you provide a full runnable example please?

[MasterA5]

https://github.com/MasterA5/flet-widget-error-test

[MasterA5]

I'm leaving the test I was trying to run in this repository.

[FeodorFitsner]

Here you go: MasterA5/flet-widget-error-test#1
"Bubble" control should have been converted to a component to work in declarative app. In general, whatever has control property assignment, e.g. some_control.some_roperty = something won't work in declarative app. Declarative UI is basically a complete re-creation of control tree on state change.

Don't be confused though, you don't necessary need to convert your app to a "new", declarative API. Using familiar imperative style is and will be supported by Flet, always.

Btw, I converted your user control to a declarative component using Codex :) - worked like a charm. Give it a try.

[MasterA5]

Oh, I see, thank you very much for your reply!!

[MasterA5]

It really works wonderfully, thank you so much!!