The Force Multiples module allows you to require that certain products can only be purchased in certain increments. For instance, you may have a widget XYZ123 that is sold in packs of 4. Force Multiples can be used to require customers to purchase XYZ123 in multiples of 4 (4, 8, 12, etc). Any or all products in the store can be required to have multiples. Products not flagged as requiring multiples are not affected by the module.
Checks are performed when products are added to the basket, or when the quantity in the basket is changed. By default the error message, which tells the customer that they are attempting to add an invalid quantity, can appear on the product, category, basket, and search screens. The error message text and formatting is completely customizable.
OpenUI or a templating system is required for displaying error messages, but MMUI stores will follow the increment criteria imposed by the module.
Force Multiples is fully template-compatible, supporting templating systems such as OpenUI SuperMod, Dynamic Templates, Category and Product Page Templates, and OpenDesigner. Tokens are provided for the error message and for the multiple required for each product.
Screenshots
Module Administration - Global Settings
Module Administration - Product Settings
Error check shown on product screen
Error check shown on basket screen