Dismissible bug in v0.23.2

[BrentHuang]

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

Describe the bug

Task exception was never retrieved
future: <Task finished name='Task-104' coro=<__run_socket_server..on_event() done, defined at D:\workspace\code\account_center_h5.venv\Lib\site-packages\flet_runtime\app.py:217> exception=JSONDecodeError('Expecting value: line 1 column 1 (char 0)')>Traceback (most recent call last):
File "D:\workspace\code\account_center_h5.venv\Lib\site-packages\flet_runtime\app.py", line 219, in on_event
await conn.sessions[e.sessionID].on_event_async(
File "D:\workspace\code\account_center_h5.venv\Lib\site-packages\flet_core\page.py", line 905, in on_event_async
await handler(ce)
File "D:\workspace\code\account_center_h5.venv\Lib\site-packages\flet_core\event_handler.py", line 18, in fn
ce = self.__result_converter(e)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\workspace\code\account_center_h5.venv\Lib\site-packages\flet_core\dismissible.py", line 122, in
self._on_confirm_dismiss = EventHandler(lambda e: DismissibleDismissEvent(e))
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\workspace\code\account_center_h5.venv\Lib\site-packages\flet_core\dismissible.py", line 295, in init
d = json.loads(e.data)
^^^^^^^^^^^^^^^^^^
File "D:\program\python\Lib\json_init.py", line 346, in loads
return _default_decoder.decode(s)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\program\python\Lib\json\decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "D:\program\python\Lib\json\decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

Code sample

Logs

import flet as ft


def main(page):
    page.window_height, page.window_width = 500, 400

    def close_yes_dlg(e):
        page.close_dialog()
        dlg.data.confirm_dismiss(True)

    def close_no_dlg(e):
        page.close_dialog()
        dlg.data.confirm_dismiss(False)

    dlg = ft.AlertDialog(
        modal=True,
        title=ft.Text("Please confirm"),
        content=ft.Text("Do you really want to delete this item?"),
        actions=[
            ft.TextButton("Yes", on_click=close_yes_dlg),
            ft.TextButton("No", on_click=close_no_dlg),
        ],
        actions_alignment=ft.MainAxisAlignment.CENTER,
    )

    def handle_confirm_dismiss(e: ft.DismissibleDismissEvent):
        print('on_confirm_dismiss')
        if e.direction == ft.DismissDirection.END_TO_START:  # right-to-left slide
            # 二次确认后再 dismiss
            dlg.data = e.control  # save current dismissible to dialog's data
            page.show_dialog(dlg)
        else:  # left-to-right slide
            # 不用二次确认的做法
            e.control.confirm_dismiss(True)

    def handle_dismiss(e):
        print('on_dismiss')
        lv.controls.remove(e.control)
        page.update()

    def handle_update(e: ft.DismissibleUpdateEvent):
        print(
            f"Update - direction: {e.direction}, progress: {e.progress}, reached: {e.reached}, previous_reached: {e.previous_reached}"
        )

    page.add(lv := ft.ListView(
        controls=[
            ft.Dismissible(
                content=ft.ListTile(title=ft.Text(f"Item {i}")),
                dismiss_direction=ft.DismissDirection.HORIZONTAL,
                background=ft.Container(bgcolor=ft.colors.GREEN),
                secondary_background=ft.Container(bgcolor=ft.colors.RED),
                on_dismiss=handle_dismiss,
                on_update=handle_update,
                on_confirm_dismiss=handle_confirm_dismiss,
                dismiss_thresholds={
                    ft.DismissDirection.END_TO_START: 0.2,
                    ft.DismissDirection.START_TO_END: 0.2,
                },
            ) for i in range(10)
        ],
        expand=True,
    ))


ft.app(main)

To reproduce

This bug is inevitable

Expected behavior

No response

Screenshots / Videos

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Operating System

Windows

Operating system details

window10

Flet version

0.23.2

Regression

Yes, it used to work in a previous Flet version (please specify the version in additional details)

Suggestions

No response

Logs

Logs

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Additional details

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