import panel as pn
import numpy as np
pn.extension()
This example creates a random number generator that periodically updates every two seconds, or with a click of a button.
This demonstrates how to add a periodic callback, how to link a button and a toggle to a couple callbacks--the former to manually generate a random number and the latter to toggle periodic generation of a random number.
def generate_random_number(event=None):
static_text.value = np.random.randint(low=100000, high=200000)
def toggle_periodic_callback(event):
if event.new is True:
periodic_cb.start()
else:
periodic_cb.stop()
static_text = pn.widgets.StaticText(name='Periodic Random Number Generator',
value='000000')
generate_button = pn.widgets.Button(name='Generate New Number')
generate_button.on_click(generate_random_number)
periodic_toggle = pn.widgets.Toggle(name='Periodically Generate',
value=True, button_type='primary')
periodic_toggle.param.watch(toggle_periodic_callback, 'value')
periodic_cb = static_text.add_periodic_callback(
generate_random_number, period=2000) # period in milliseconds
col = pn.Column(generate_button, periodic_toggle, static_text)
col.servable()