display weight of products in invoice

Hi,

The PDF invoice plugin already supports this, through three hidden settings of the HikaShop configuration (they apply to the normal invoice too):
- show_invoice_unit_weight: adds a column with the weight of one unit of each product
- show_invoice_total_weight: adds a column with the weight of each line (unit weight x quantity)
- show_invoice_weight: adds the total weight of the order below the totals

There is no option for them in the configuration page, so you need to add them in your database, with phpMyAdmin for example. Replace xxx_ with the prefix of your tables and only keep the lines you want:

INSERT INTO xxx_hikashop_config (config_namekey, config_value, config_default) VALUES
('show_invoice_unit_weight', '1', '1'),
('show_invoice_total_weight', '1', '1'),
('show_invoice_weight', '1', '1')
ON DUPLICATE KEY UPDATE config_value = '1';