Please add option for variations (New feature)
Some other shopping cart modules, in other systems (opencart, shopify, etc), have an option for variations.
For example, you have for a product(shirt) an option with colors (blue, black, white), but additionally you have some sizes for each color (s,m,l), so a variation can be shirt blue in small, with his own price and ref code, other shirt can be red in large, etc.
This is a new feature, but is the only feature i think opencart needs to be the most complete shopping cart solution.
This already exists as "options".
But in options you can’t merge options with different codes and prices
No, you need to use models for that.
Prices go onto model, however you can add additions cost onto options. So depending what you need you can do it with models and options.
However codes must go on model.
I assume you want options linked to models. Which does sound a good idea. but, I'm unsure it's needed and the amount of work to make that fit the current structure is big and I'm not sure it will be backward compatible.
However. A reference "code" on options is a good idea. I'll put this change on the list, but just to add a reference "code" filed to the options.