Routing

Use on and handle_on to simplify query handling by routing queries to designated functions.

from h2o_wave import main, app, Q, ui, on, handle_on
# This function is called when q.args['empty_cart'] is True.
@on(arg='empty_cart')
async def clear_cart(q: Q):
q.page['cart'].items[0].text.content = 'Your cart was emptied!'
await q.page.save()
# If the name of the function is the same as that of the q.arg, simply use on().
# This function is called when q.args['buy_now'] is True.
@on()
async def buy_now(q: Q):
q.page['cart'].items[0].text.content = 'Nothing to buy!'
await q.page.save()
# This function is called when q.args['#'] is 'about'.
@on(arg='#about')
async def handle_about(q: Q):
q.page['blurb'].content = 'Everything here is gluten-free!'
await q.page.save()
# This function is called when q.args['#'] is 'menu/spam', 'menu/ham', 'menu/eggs', etc.
# The 'product' placeholder's value is passed as an argument to the function.
@on(arg='#menu/{product}')
async def handle_menu(q: Q, product: str):
q.page['blurb'].content = f"Sorry, we're out of {product}!"
await q.page.save()
@app('/demo')
async def serve(q: Q):
if not q.client.initialized:
q.client.initialized = True
q.page['nav'] = ui.markdown_card(
box='1 1 4 2',
title='Menu',
content='[Spam](#menu/spam) / [Ham](#menu/ham) / [Eggs](#menu/eggs) / [About](#about)',
)
q.page['blurb'] = ui.markdown_card(
box='1 3 4 2',
title='Description',
content='Welcome to our store!',
)
q.page['cart'] = ui.form_card(
box='1 5 4 2',
title='Cart',
items=[
ui.text('Your cart is empty!'),
ui.buttons([
ui.button(name=buy_now.__name__, label='Buy Now!', primary=True),
ui.button(name='empty_cart', label='Clear cart'),
])
],
)
await q.page.save()
else:
await handle_on(q)

Tags: โ€‚routing