Laravel many-to-many polymorphic relationship - custom methods/relationships on pivot

Question

I have an issue with a many-to-many polymorphic relationship (diagram below). In a food shop some products have options/variants, e.g. pizza comes in variants of 7inch, 12inch, 16inch. When pizza is added to cart a variant must be selected.

When an order is saved - bought products (without variants) are saved in the orderables table - variants that are bought are saved in variant_orderables table

Btw, the pivot tables are called orderables and variant_orderables instead of what you might expect according to Laravel conventions, e.g. "customer_order_product", because in addition to customer_orders, the products and variants are also in a polymorphic relationship with stock_orders (where the shop buys those items from suppliers). I just didn't show all that on the diagram to keep it simple.

Anyway, bought items, be they products or variants, can have "extras" added to them in the order. E.g. A pizza can have extra cheese, or pepperoni as extras (info contained in the extras_groups_offers table).

ordered_extras is where we will list the product or variant id of the extras that have been ordered, along with the orderables or variant_orderables id that the extras are applied on.

So between variants and customer_orders, variant_orderables is the pivot, but then variant orderables has a relationship with extras_groups_offers with ordered_extras as the pivot.

I know I probably need to do something with newPivot, but as this involves a few polymorphic many-to-many relationships, I'm not exactly sure how to go about it. If anyone could give me a simple example solution, I'd be very grateful.

Basically, I am trying to reach a stage where I can eager load all the necessary information for an order, including products/variants ordered, and all the ordered extras for each product/variant that has been ordered. I just don't know how to go about it.

Thanks.

Answer 1

I've overcome the problem by making the orderables and variant_orderables tables as normal models. This means I do have more chaining to do in terms of relationships, but I can at least eager load multiple nested layers easily, e.g. order.orderProducts.extrasGroupsOffers (P.S. orderables has been renamed to order_product, if you're wondering where that came from)