What is the best way to implement a forced page refresh using Flask?

Question

Background
I have a large number of fields that will be updating real time from an external process. I would like to update the Flask hosted pages periodic

Answer 1

One way to achieve this is in Flask through WebSockets using flask-socketio. I use APScheduler for the background process in the example, but any background process will do. this updates a price on the webpage every 4 seconds:

from flask import Flask, render_template
from apscheduler.schedulers.background import BackgroundScheduler
from flask_socketio import SocketIO, emit

app = Flask(__name__)
socketio = SocketIO(app)

#defines the job
def job():
    new_price = get_new_price();
    #job emits on websocket
    socketio.emit('price update',new_price, broadcast=True)

#schedule job
scheduler = BackgroundScheduler()
running_job = scheduler.add_job(job, 'interval', seconds=4, max_instances=1)
scheduler.start()

@app.route('/')
def index():
    return render_template('index.html')

if __name__ == '__main__':
    socketio.run(app, host='0.0.0.0')

Then the index.html template is: