Well, I want to write an async app on Flet with Telethon. It;s my first time so do not judge strictly pls.

That’s my code

main.py

import flet as ft
import main_page


async def main(page: ft.Page):
    page.title = "Telegram resender 3000"
    page.horizontal_alignment = ft.CrossAxisAlignment.START
    await page.update_async()

    await page.add_async(main_page.MainPage(page))


if __name__ == "__main__":
    ft.app(target=main)

main_page.py

import flet as ft
import telethon
from .load_env import *
import asyncio
import os

import support_classes as sc


class MainPage(ft.UserControl):

    def __init__(self, page):
        super().__init__()
        self.page = page

    def build(self):
        self.idx = 0
        # create text
        self.add_account_text = ft.Text(value="Add your tg account here")

        # create input for writing phone number and ADD btn
        self.add_phone_number = ft.TextField(
            hint_text="Enter your phone number")
        self.add_phone_btn = ft.FloatingActionButton(
            icon=ft.icons.ADD, on_click=self.register_new_acc)

        self.accs_list = ft.Row(controls=[])  # create field for tg accs
        self.upload_tg_accs_btn = ft.IconButton(
            icon=ft.icons.DOWNLOAD,
            icon_color="blue400",
            icon_size=30,
            tooltip="Upload existing telegram accounts",
            on_click=self.get_tg_accs,
        )

        self.add_account_part = ft.Column(
            width=300,
            controls=[
                ft.Row(
                    controls=[
                        self.add_account_text,
                        self.add_phone_number,
                        self.add_phone_btn
                    ]
                ),
                ft.Row(controls=[
                    self.accs_list,
                    self.upload_tg_accs_btn,
                ]),
            ])

        return self.add_account_part

    async def register_new_acc(self, e):

        # add field for code
        self.code_recieve_input = ft.TextField(
            hint_text="Enter the code and wait...")

        self.add_account_part.controls.append(self.code_recieve_input)
        await self.add_account_part.update_async()

        # create a session and get request for a code
        client = telethon.TelegramClient(
            str(self.idx), api_id=api_id, api_hash=api_hash)

        # save the phone
        phone = self.add_phone_number.value

        # make input empty
        self.add_phone_number.value = ""

        await client.start(phone=phone, code_callback=lambda: self.code_receive(phone))

    async def code_receive(self, phone):
        # wait for user's answer
        await asyncio.sleep(30)

        # remove code input
        self.add_account_part.controls.remove(self.code_recieve_input)
        await self.add_account_part.update_async()

        # add a new acc to a list
        acc = sc.TGAcc(
            num=self.code_recieve_input.value,
            idx=self.idx,
            del_func=self.delete_acc
        )

        self.accs_list.controls.append(acc)
        await self.accs_list.update_async()

        # add number to a storage
        tg_accs = {}
        # if we already have nums
        if self.page.client_storage.contains_key_async("tg_accs"):
            tg_accs = self.page.client_storage.get("tg_accs")

        self.page.client_storage.set("tg_accs", tg_accs + {self.idx: phone})

        self.idx += 1  # increase the idx (of accounts)
        return self.code_recieve_input.value

    async def delete_acc(self, acc):
        # delete from list and update
        self.accs_list.controls.remove(acc)
        await self.accs_list.update_async()

        # remove session file
        os.remove(f'{acc.idx}.session')

    async def get_tg_accs(self, e):

        # create list of all connected accs
        if self.page.client_storage.contains_key('tg_accs'):
            accs_list = [sc.TGAcc(num=v, idx=k, del_func=self.delete_acc)
                         for k, v in self.page.client_storage.get("tg_accs").items()]

        # set our data
        self.accs_list.controls = accs_list

        await self.accs_list.update_async()

tg_acc.py

import flet as ft
import os

class TGAcc(ft.UserControl):
    
    def __init__(self, num, idx, del_func):
        super().__init__()
        self.num = num
        self.idx = idx
        self.del_func = del_func
        
    def build(self):
        # build the container
        self.container = ft.Column(
            controls=[
                ft.Row(
                    controls=[
                        ft.Text(f"{self.idx} = {self.num}"),
                        ft.IconButton(
                            icon=ft.icons.DELETE_FOREVER_ROUNDED,
                            icon_color="pink600",
                            icon_size=30,
                            tooltip="Delete account",
                            on_click=self.delete_acc
                        )
                    ]
                )
            ]
        )
        
        return self.container
    
    async def delete_acc(self, e):
        await self.del_func(self)

Also I have load_env.py file there I load all secret data.

And I "sorted" these file into folders so that’s the screen. I also added screen of UI.

**So, problem: **
I need to load data from client_storage in startup of a program and after write it into self.accs_list.controls. idk how do it on startup of all, so I created a download btn, by clicking on it data should load but all that loads is an exception raise NotImplementedError().

I tried to delete self.page = page in init of MainPage and just use self.page everywhere in code below but no result has appeared(

Here an error, that’s always the same

Task exception was never retrieved
future: <Task finished name='Task-15' coro=<__connect_internal_async.<locals>.on_event() done, defined at /home/felix/anaconda3/envs/telegram_bot/lib/python3.10/site-packages/flet_runtime/app.py:425> exception=NotImplementedError()>
Traceback (most recent call last):
  File "/home/felix/anaconda3/envs/telegram_bot/lib/python3.10/site-packages/flet_runtime/app.py", line 427, in on_event
    await conn.sessions[e.sessionID].on_event_async(
  File "/home/felix/anaconda3/envs/telegram_bot/lib/python3.10/site-packages/flet_core/page.py", line 482, in on_event_async
    await handler(ce)
  File "/home/felix/Documents/code/flet-telegram-repost/main_page/main_page.py", line 115, in get_tg_accs
    if self.page.client_storage.contains_key('tg_accs'):
  File "/home/felix/anaconda3/envs/telegram_bot/lib/python3.10/site-packages/flet_core/client_storage.py", line 46, in contains_key
    self.__page.invoke_method(
  File "/home/felix/anaconda3/envs/telegram_bot/lib/python3.10/site-packages/flet_core/page.py", line 859, in invoke_method
    result = self._send_command(
  File "/home/felix/anaconda3/envs/telegram_bot/lib/python3.10/site-packages/flet_core/page.py", line 700, in _send_command
    return self.__conn.send_command(
  File "/home/felix/anaconda3/envs/telegram_bot/lib/python3.10/site-packages/flet_core/connection.py", line 21, in send_command
    raise NotImplementedError()
NotImplementedError

idk how to fix my problem, in docs any examples with the client_storage + ft.UserControl I didnt find. That’s my first time so I can do veeeery stupid mistakes.

If anyone knows how to load data from client_storage on startup of Flet app write pls, I listen carefully)