How to use Onchange with date field in odoo?

Question

field declaration

    price=fields.Integer(string="Price")
    service_date=fields.Date(string="Last servicing date")
    service_charge=fields.Integer(string="Last Service Charge")
    total_charge=fields.Integer(string="Total Spent")

onchange Function in which servie_date is used as argument

    @api.onchange('service_date')
    def _onchange_total_charge(self):
        if self.total_charge > 0:
            self.total_charge+=self.service_charge
        else:
            self.total_charge=self.price+self.service_charge

Answer 1

@api.onchange('service_date')
@api.depends('service_date')
def _onchange_total_charge(self):
    if self.total_charge > 0:
        self.total_charge += self.service_charge
    else:
        self.total_charge = self.price + self.service_charge

Try to re-write the code like this