Apply Quantity Discounts across all products in a category
Prestashop 1.2 – 1.3 Source: http://www.prestashop.com/forums/topic/75558-mod-quantity-discounts-for-all-the-products-in-the-same-default-category/
Prestashop 1.4 – 1.6 Source: http://www.prestashop.com/forums/topic/140803-free-module-category-quantity-discount-apply-quantity-discounts-across-all-products-in-a-category/
Quantity discount is calculated based on the price of product. For promotion mechanics below, if we use the built-in sale price function for 1 product, the quantity discount will be calculated based on the discounted price of 1 product.
Purchase 1 items 10% off
Purchase 2 items 15% off
Purchase 3 items 20 % off
Purchase 4 items 25 % off
Purchase 5 items 30% off
Purchase 6 items 35% off
So we disable the admin check for minimum more than 1 quantity in order to allow creating quantity discount % for purchase of 1 product.
change: admin/tabs/AdminProducts.php
elseif (!($quantity_discount = intval(Tools::getValue(‘quantity_discount’))) OR $quantity_discount <= 1) $this->_errors[] = Tools::displayError(‘quantity is required and must be superior of 1’);
to
elseif (!($quantity_discount = intval(Tools::getValue(‘quantity_discount’))) OR $quantity_discount <= 0) $this->_errors[] = Tools::displayError(‘quantity is required and must be superior of 0’);