Sending notifications

Tryton embeds a bus system allowing the system to send text messages to clients logged in the system.

It allows the server to warn quickly the client user about some events using the notify() function. Sending the notifications is done in a transactional way and will occur at then end of the transaction.

For example, we warn the user of low stock level when selecting a product:

from trytond.bus import notify

class SaleLine:
    __name__ = 'sale.line'

    def on_change_product(self):
        super().on_change_product()
        if compute_stock(self.product) < 0:
            notify('Not enough stock', priority=3)