Program custom condition
You should use hook “wdp_conditions” to append new condition + load new PHP class and html template.
You should use one plugin to add many custom conditions.
You need to install this plugin as usually through > Plugins > Add new.
Please, review sample addons.
For example, we have custom product field “area” (different for each product).
Sample addon embeds new condition to section “Cart Conditions”.
Template custom-template-area-size.php describes supported operations and input for comparable value.
The addon uses method check (class WDP_Custom_Condition_Area_Size) to get total area and compare with defined value.