Callback triggered by timestamp of store component

Dash Python
1

Hi,
The store component in dash (dcc.Store) has attribute modified_timestamp but is there a way to know when store component is updated, even when data remains the same?
I tried to use the code below, which gets the timestamp in dcc-timekeeper. However, it seems that when updating the store component, other callbacks are not working. I expect that after selecting a value in dropdown, and then click the button, it should return ‘button is clicked’. But there’s no response.

import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
import time

app = dash.Dash()

app.layout = html.Div([
    html.Div(id='dcc-timekeeper', children='0', style={'display': 'none'}),
    dcc.Store(id='intermediate', modified_timestamp=0),
    dcc.Dropdown(id='dcc-item',
                 options=[
                     {'label': 'AAAAA', 'value': 'AAAAA'},
                     {'label': 'BBBBB', 'value': 'BBBBB'}
                 ],
                 value='AAAAA'
                 ),
    html.Button(id='button',
                children='button',
                n_clicks_timestamp='0'),
    html.Div(id='results')

])

@app.callback(
    Output('intermediate', 'data'),
    [Input('dcc-item', 'value')]
)
def update_in(value):
    time.sleep(10)
    return 'data'

@app.callback(Output('dcc-timekeeper', 'children'),
              [Input('intermediate', 'data')])
def update_timebase_nclick(value):
    return '{}'.format(int(time.time() * 1000))

@app.callback(Output('results', 'children'),
              [Input('button', 'n_clicks_timestamp'),
               Input('dcc-timekeeper', 'children')])
def slider_buttons(button, dcc):
    if int(button)>int(dcc):
        val = 'button is clicked'
    else:
        val = 'dcc.Store value updated'
    return val

if __name__ == '__main__':
    app.run_server(debug=True)

Would really appreciate any help!

2

@caiyij Actually the store component should fire up everytime you write to the data property. It doesn’t matter if the value is the same as it was before. I use the Store component as a trigger for other callbacks and write True to them everytime I want to execute a callback. I use memory as storage_type.