Simplify the variation UX when each product has a single variation

Bojanz - if there is no objection, I'd like to take a shot at this.

Go for it! : )

@Bojanz,

After a couple of hours, the validation seems straightforward enough. Let me know if you see an issue with my plan

• I added a validator to the product_id field when creating a new variation
• When we first create the product, and add variations, the product_id is empty. This is because the product is created in the form submit process. So I would call the same validation check from the form validate function.

I don't see that part of the issue as being too complex, but I'm digging into the Commerce 2.x code for the first time. Am I missing some subtle point?

Ah, total bad thinking on my part. I see what you are thinking. I was adding the constraint when the product variation was being created, when I can just put it on the product creation form. I don't see that as elegant, but from a code point of view, it is easier to accomplish.

If this is enforced, how would you handle a product that is, for example, a charitable donation - where the only varying attribute is a range of fixed amounts?

@bojanz i see the variations field is locked in product type entity. So as you said, can we add a number field in product type form at Drupal\commerce_product\Form\ProductTypeForm form method and in submit, i see

    if ($status == SAVED_NEW) {
      commerce_product_add_stores_field($this->entity);
      commerce_product_add_body_field($this->entity);
      commerce_product_add_variations_field($this->entity);
    }

so commerce_product_add_variations_field() function adds a cardinality of unlimited to variations field. Do we need to pass the cardinality, so that user can set it? also should we allow only once on initial creation for changing the cardinality?

Sprinting at DC Baltimore.