How to update dash by another script?

hamedk · December 31, 2020, 3:35pm

I have a script that produces CSV files every 5 minutes and dash script reads these CSV files. I want to update the dash script when another script runs. What’s the solution? without using the Interval method.

Emil · December 31, 2020, 3:45pm

You can use the Interval component to update the web page regularly (e.g. once per minute), or you could use the WebSocket component from dash-extensions to push the changes, when they are ready.

hamedk · December 31, 2020, 4:43pm

Thanks. I don’t want to use the Interval. Can I send a command from another script to dash script for updating? could you please explain more?

Emil · December 31, 2020, 5:51pm

Here is some inspiration,

github.com

thedirtyfew/dash-extensions/blob/master/examples/websocket_push.py

import dash_html_components as html

from dash import Dash
from dash.dependencies import Input, Output
from dash_extensions.websockets import SocketPool, run_server
from dash_extensions import WebSocket

# Create example app.
app = Dash(prevent_initial_callbacks=True)
socket_pool = SocketPool(app)
app.layout = html.Div([html.Div(id="msg"), WebSocket(id="ws")])
# Update div using websocket.
app.clientside_callback("function(msg){return \"Response from websocket: \" + msg.data;}",
                        Output("msg", "children"), [Input("ws", "message")])


# End point to send message to current session.
@app.server.route("/send/<message>")
def send_message(message):
    socket_pool.send(message)

This file has been truncated. show original

For your use case, i guess you would run the code to collect the data, and then broadcast a message whenever new data arrives.

DavidBoja · July 26, 2023, 11:03am

@Emil The original code you shared is not available anymore - could you share it again?

Topic		Replies	Views
Dash content update from external websocket client Dash Python	0	752	January 11, 2022
Instead of Interval component running function every few seconds, have live function update Dash itself arbitrarily? Dash Python	4	997	February 14, 2019
Server Side Update Dash Python	5	2431	April 18, 2019
Update on both interval and Button? (or just make callback do nothing) Dash Python	3	1059	April 23, 2020
Updating DataTable data using WebSocket Dash Python	4	2368	February 26, 2022

How to update dash by another script?

Related topics