Hello

I am trying to add a button which would cancel calculation but while the calculation function is running the cancel button is not working (the `cancel_calculation_button_callback`

is not triggering).

```
def calculate_timesteps():
for element in elements:
if cancel_calculation_button.disabled==False:
//data manipulation to get dictionary elements
return data
calculate_data_button = Button(label="Calculate data", width=200)
cancel_calculation_button = Button(label="Cancel calculation", width=200, disabled=False, button_type="danger")
data = calculate_timesteps()
cancel_calculation_button.disabled=True
source = ColumnDataSource(data=data)
def calculate_data_button_callback():
cancel_calculation_button.disabled=False
calculate_data_button.label = "Loading..."
calculate_data_button.button_type = "primary"
calculate_data_button.disabled=True
def do_calculation():
data = calculate_timesteps()
source.data = data
calculate_data_button.label = "Calculate data"
calculate_data_button.button_type = "default"
calculate_data_button.disabled=False
cancel_calculation_button.disabled=True
curdoc().add_next_tick_callback(do_calculation)
def cancel_calculation_button_callback():
cancel_calculation_button.disabled=True
calculate_data_button.on_click(cancel_calculation_button_callback)
calculate_data_button.on_click(calculate_data_button_callback)
layout = column(
calculate_data_button,
cancel_calculation_button,
)
curdoc().add_root(layout)
```

How could I make it work?

I guess, I should somehow use `add_periodic_callback`

but I am not really sure how to implement it in the for loop.

Thanks.