Where the presence of an object is being validated and that object comes from an *association*, we should use `validates :object, presence: true` instead of `validates :object_id, presence: true`.
This does not apply in the same way to validations on uniqueness of certain attributes, such as `validates :object_id, uniqueness...`
This fixes the error UK's is experiencing:
```
PG::AmbiguousColumn: ERROR: column reference "state" is ambiguous LINE
1: SELECT DISTINCT spree_orders.*, CASE WHEN state IN ('cancele...
^ : SELECT DISTINCT spree_orders.*, CASE WHEN state IN ('canceled',
'returned') THEN payment_total WHEN state IS NOT NULL THEN payment_total
- total ELSE 0 END AS balance_value, spree_orders.* FROM "spree_orders"
INNER JOIN "spree_shipments"
```
See
https://app.bugsnag.com/yaycode/openfoodnetwork-uk/errors/6058c45989d37300079e8312?event_id=6058ccd30075af73bcb20000&i=sk&m=nw.
- Code is at a single place
- No need to import `localizeCurrencyFilter` into Controllers that required unit_prices
- Add `currencyconfig` into unit_prices_spec as it's now dependant to localizeCurrencyFilter
- Add method `processUnitPrice` which is responsible for computing the right unit price, that depends on `price`, `variant_unit_scale`, `variant_unit`, `unit_value` and `variant_unit_name`
- Watch the needed model to compute the unit price: `product.price` and `product.variant_unit_name`
- Add dependencies : UnitPrices and localizeCurrencyFilter
- Add currencyconfig to spec, as it's needed by localizeCurrencyFilter
- Put `'ng-controller' => 'unitsCtrl'` to the relevant node.
- Add new ng-model, as it's needed to watch it in order to compute unit price : `product.price`
- Finally display the needed information: `product.unit_price_value` and `product.unit_price_unit`
- Arguments were misordered and `scale` is needed to compute the denominator.
- Reorder "state machine" if-else as variant_unit_name is priority and "item" is too.
- @andrewpbrett I need your review here ;)
- Still need to test imperial system
- Test that the unit price wrapper is here
- Click on the question mark icon and display the tooltip
- Click outside the question mark icon and hide the toolip
This moves them to a more unit-like style where the mailer methods are
the subjects. However, I did so only for the methods that show order
balance and thus we want to be extra sure of their coverage.
