Odoo 8 Allow Negative Invoice Line Item

Question

I have a product called "Coupon" with negative amount which is used to offset the product price. However, it seems like Odoo 8 does not allow computation of negative amount to price_subtotal (it becomes 0.00):

Coupon ... ... 1 Each -40.0000 0.0000

When I remove the negative sign, it computes

Coupon ... ... 1 Each  40.0000 40.0000

From an accounting perspective, the total invoice should not be negative. That stays true. However, I do need to allow negative computation of invoice line item(s). Where and what do I need to change? I tried looking into account/account.py but to no avail so far - it's all just "tax" related.

Thanks in advance!

Details of the amount column for the line total

class account_invoice(models.Model)
    ....

    @api.one
    @api.depends('invoice_line.price_subtotal', 'tax_line.amount')
    def _compute_amount(self):
        self.amount_untaxed = sum(line.price_subtotal for line in self.invoice_line)
        self.amount_tax = sum(line.amount for line in self.tax_line)
        self.amount_total = self.amount_untaxed + self.amount_tax

    ....

class account_invoice_line(models.Model):
    _name = "account.invoice.line"
    _description = "Invoice Line"
    _order = "invoice_id,sequence,id"

    @api.one
    @api.depends('price_unit', 'discount', 'invoice_line_tax_id', 'quantity',
        'product_id', 'invoice_id.partner_id', 'invoice_id.currency_id')
    def _compute_price(self):
        price = self.price_unit * (1 - (self.discount or 0.0) / 100.0)
        taxes = self.invoice_line_tax_id.compute_all(price, self.quantity, product=self.product_id, partner=self.invoice_id.partner_id)
        self.price_subtotal = taxes['total']
        if self.invoice_id:
            self.price_subtotal = self.invoice_id.currency_id.round(self.price_subtotal)

    @api.model
    def _default_price_unit(self):
        if not self._context.get('check_total'):
            return 0
        total = self._context['check_total']
        for l in self._context.get('invoice_line', []):
            if isinstance(l, (list, tuple)) and len(l) >= 3 and l[2]:
                vals = l[2]
                price = vals.get('price_unit', 0) * (1 - vals.get('discount', 0) / 100.0)
                total = total - (price * vals.get('quantity'))
                taxes = vals.get('invoice_line_tax_id')
                if taxes and len(taxes[0]) >= 3 and taxes[0][2]:
                    taxes = self.env['account.tax'].browse(taxes[0][2])
                    tax_res = taxes.compute_all(price, vals.get('quantity'),
                        product=vals.get('product_id'), partner=self._context.get('partner_id'))
                    for tax in tax_res['taxes']:
                        total = total - tax['amount']
        return total

Thanks @SDBot trying to trace but can't seem to find anything that restricts the amount to 0 if price_unit is of negative value yet.... help? — jeszy
Activate developer mode (top right, click on about odoo), find out which model that field belong to, it's most likely is a computed field, look into the computed field's method if you can't find anything there, try post the method here. — SDBot
@CZoellner runbot.odoo.com helped a great deal! I didn't realize that it was a piece of the custom code that was doing the restriction - kept thinking it was from Odoo 8 itself. — jeszy
@CZoellner It was done by my predecessor :) That said, what I did was to add a level of condition prior to the customized conditions to ensure that it is not of the specific product and that the value is not negative. Worked like a charm. Thank you for pointing out runbot.odoo.com! — jeszy

CZoellner CZoellner · Accepted Answer · 2016-05-05T19:41:26

Odoo's default behaviour is handling it as expected. The problem is custom code. (For more information read the questions comments)

Odoo 8 Allow Negative Invoice Line Item

1 Answers