How to use progress bar

[JaniKallankari]

I have tried to make progress bar for invoke_long_callback function. Here is my code that updates the progress variable calculus_progess. Unfortunatelly the UI dosen't get updated. I have added manual refresh, broadcast and add_shared_variable with no luck.
Any ideas how to get this work? Here is my current code

from taipy.gui import Gui
import taipy.gui.builder as tgb
from taipy.gui import Gui, State, get_state_id, invoke_callback, invoke_long_callback
import time

calculus_progess = 1

def do_progress(state_id):
    global gui
    for i in range(10):
        invoke_callback(gui, state_id, update_progress, (10*i,))
        time.sleep(1)
    return

def start_progress(state):
    invoke_long_callback(
        state=state,
        user_function=do_progress,
        user_function_args=[get_state_id(state)]
    )

def update_progress(state: State, val):
    state.calculus_progess = val
    state.refresh("calculus_progess")
    state.get_gui().broadcast_change("calculus_progess", val)

if __name__ == "__main__":
    with tgb.Page() as page:
        tgb.progress(calculus_progess)
        tgb.button('Start',on_action='start_progress')
    pages = {
        "/":page,
    }
    gui = Gui(pages=pages)
    gui.add_shared_variable("calculus_progess")
    gui.run(title="Progress",use_reloader=False,debug=True)

[arcanaxion]

Hello! This is a great opportunity to try out the new "asynx" syntax for long callbacks which was made available in Taipy 4.1:

import time

import taipy.gui.builder as tgb
from taipy.gui import Gui, State

calculus_progress = 0


async def start_progress(state: State):
    for i in range(11):
        state.calculus_progress = 10 * i
        time.sleep(1)


with tgb.Page() as page:
    tgb.progress("{calculus_progress}", show_value=True, title="Calculus Progress")
    tgb.button("Start", on_action=start_progress)

if __name__ == "__main__":
    pages = {"/": page}
    gui = Gui(pages=pages)

    # This will make the "calculus_progress" value be shared with all connected sessions/browsers
    # gui.add_shared_variable("calculus_progress")

    gui.run(title="Progress")

You just need the declare the callback function as a coroutine (with async def), and Taipy will run it in a separate thread.

If you are on an older version or just specifically need to use the invoke_long_callback approach, do let me know and I'll write an example of that for you.

Thanks for raising this discussion -- we need to document this feature. Feel free to close this discussion if it answers your question.