Error after upgrading to 0.24: ValueError: Circular reference detected

[mvwilpe]

This error occurs after page.add of several controls. E.g.
page.add(
ft.AppBar(
title=self.path_dir_data_text,
actions=[
ft.PopupMenuButton(
tooltip=cm.SHOW_MENU,
items=popup_items
)
]
)
)

When I remove this page.add the same error occurs after some other update().
Everything worked fine upto version 0.23.2.

Debug trace (The page.add of the code above happens at line 280):
Unhandled error processing page session : Traceback (most recent call last):
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_runtime/app.py", line 244, in on_session_created
await asyncio.get_running_loop().run_in_executor(
File "/usr/lib/python3.12/concurrent/futures/thread.py", line 58, in run
result = self.fn(*self.args, **self.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/GeneRoSa.py", line 388, in flet_target
GeneRosaApp(page).load()
File "/home/martin/PycharmProjects/GeneRoSa/GeneRoSa.py", line 167, in load
self.build_app()
File "/home/martin/PycharmProjects/GeneRoSa/GeneRoSa.py", line 280, in build_app
page.add(
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/page.py", line 735, in add
r = self.__update(self)
^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/page.py", line 833, in __update
commands, added_controls, removed_controls = self.__prepare_update(*controls)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/page.py", line 849, in __prepare_update
control.build_update_commands(
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 467, in build_update_commands
ctrl.build_update_commands(
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 467, in build_update_commands
ctrl.build_update_commands(
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 467, in build_update_commands
ctrl.build_update_commands(
[Previous line repeated 6 more times]
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 388, in build_update_commands
update_cmd = self._build_command(update=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 561, in _build_command
self.before_update()
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/container.py", line 236, in before_update
self._set_attr_json("image", self.__image)
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 178, in _set_attr_json
nv = self._convert_attr_json(value)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 184, in _convert_attr_json
json.dumps(value, cls=EmbedJsonEncoder, separators=(",", ":"))
File "/usr/lib/python3.12/json/init.py", line 238, in dumps
**kw).encode(obj)
^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/embed_json_encoder.py", line 44, in encode
return super().encode(self._convert_enums(o))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/json/encoder.py", line 200, in encode
chunks = self.iterencode(o, _one_shot=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/json/encoder.py", line 258, in iterencode
return _iterencode(o, 0)
^^^^^^^^^^^^^^^^^
ValueError: Circular reference detected

Future exception was never retrieved
future: <Future finished exception=ValueError('Circular reference detected')>
Traceback (most recent call last):
File "/usr/lib/python3.12/concurrent/futures/thread.py", line 58, in run
result = self.fn(*self.args, **self.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/page.py", line 944, in wrapper
handler(*args)
File "/home/martin/PycharmProjects/GeneRoSa/GeneRoSa.py", line 311, in handle_window_close
self.page.window.destroy()
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/page.py", line 480, in destroy
self.page.update()
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/page.py", line 719, in update
r = self.__update(self)
^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/page.py", line 833, in __update
commands, added_controls, removed_controls = self.__prepare_update(*controls)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/page.py", line 849, in __prepare_update
control.build_update_commands(
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 467, in build_update_commands
ctrl.build_update_commands(
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 467, in build_update_commands
ctrl.build_update_commands(
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 467, in build_update_commands
ctrl.build_update_commands(
[Previous line repeated 6 more times]
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 388, in build_update_commands
update_cmd = self._build_command(update=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 561, in _build_command
self.before_update()
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/container.py", line 236, in before_update
self._set_attr_json("image", self.__image)
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 178, in _set_attr_json
nv = self._convert_attr_json(value)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/control.py", line 184, in _convert_attr_json
json.dumps(value, cls=EmbedJsonEncoder, separators=(",", ":"))
File "/usr/lib/python3.12/json/init.py", line 238, in dumps
**kw).encode(obj)
^^^^^^^^^^^
File "/home/martin/PycharmProjects/GeneRoSa/.venv/lib/python3.12/site-packages/flet_core/embed_json_encoder.py", line 44, in encode
return super().encode(self._convert_enums(o))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/json/encoder.py", line 200, in encode
chunks = self.iterencode(o, _one_shot=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/json/encoder.py", line 258, in iterencode
return _iterencode(o, 0)
^^^^^^^^^^^^^^^^^
ValueError: Circular reference detected

Process finished with exit code 0

[mvwilpe]

Additional information. The error is originating in the encode method of the EmbedJsonEncoder in module embed_json_encoder.py.
I've put a try-except around the call to super().encode like:

def encode(self, o):
    try:
        return super().encode(self._convert_enums(o))
    except Exception as e:
        print(f'super().encode(self._convert_enums({o}))')

The following lines are printed:
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': False, 'height': 200, 'fit': 'contain', 'n': 'content'}))
super().encode(self._convert_enums(image {'expand': 1, 'visible': True, 'height': 200, 'fit': 'contain', 'n': 'content', 'src': 'Data/Afbeeldingen/i000000366.jpg'}))

Furtermode: the app seems to run ok when this try-except is in place.
The error seems to occur everytime the src parameter of an Image is changed.

[mvwilpe]

Further investigation shows that the circular reference occurs due to item[1] being equal to ('bgcolor', ('primarycontainer', False))

[mvwilpe]

The quick fix for now is catching the value error due to circular reference which for my app seems to have no further negative consequences:

def encode(self, o):
try:
return super().encode(self._convert_enums(o))
except ValueError:
pass

[ndonkoHenri]

Please share some runnable code to test the issue.

[mvwilpe]

I was trying to find a minimal example to share as runnable coude when I found out what was wrong.
I initalized a class follows:

class ImageFileField(ft.Container):

def __init__(self) -> None:
    super().__init__()

    self.label = "some label"
    self.file_name: ft.Text = ft.Text()
    self.image: ft.Image = ft.Image()
    self.content = ft.Container(
        content=self.image
    )

As it turns out the error occurs because I named the instance of Image self.image. As it happens image is an existing property of Container. So the solution was simply to rename it and everything works fine...

So its my bad and not a Flet error ;)