Money Rails - Order Of Amount And Currency

Question

Does the money-rails gem require a specific order of price and currency when initializing an object? For example, take a look at the following:

Object.new(currency: 'JPY', price: 25)
=> #<Object id: nil, price_cents: 25, currency: "JPY">

If we specify the price first, we get an incorrect value (2500) for the price:

Object.new(price: 25, currency: 'JPY')
=> #<Object id: nil, price_cents: 2500, currency: "JPY">

Object contains the following: monetize :price_cents.

In the code above there is no one line where `RubyMoney` gem is involved. `Object#new` is not overwritten by `RubyMoney` afaik. — Aleksei Matiushkin, Jan 27 '16 at 12:15
You had to assume that we're using the gem. I editing the question to show that `Object` is monetizing `price_cents`. — Artem Kalinchuk, Jan 27 '16 at 12:18
I do not have to assume anything. You are talking about `money-rails` gem, that transparently makes use of `monetize` gem; you’ve never mentioned neither of them in the question. `RubyMoney` itself does not have `monetize` method. — Aleksei Matiushkin, Jan 27 '16 at 12:21
Have you passed [`:with_model_currency`](https://github.com/RubyMoney/money-rails#instance-currencies) to `monetize` DSL? — Aleksei Matiushkin, Jan 27 '16 at 12:41
If the currency is not a subject toi change from one model instance to another, it makes no sense to pass a currency to constructor. — Aleksei Matiushkin, Jan 27 '16 at 12:51
Than re-read the documentation I linked in my previous comment _carefully_. — Aleksei Matiushkin, Jan 27 '16 at 12:52
The side-effect you encountered is likely produced my implicit money convertion to JPY, that apparently has no cents, and since the gem is not aware of that the currency is a subject to change, it performs the rude conversion. On the other hand, when the currency is received as the first argument, no conversion is done, obviously. — Aleksei Matiushkin, Jan 27 '16 at 12:55
`with_model_currency: :currency` does not change anything. The order of `currency` and `price` needs to be specific in order for it to store the correct value. The issue is that I don't control over the order that is sent over an API, for example. — Artem Kalinchuk, Jan 27 '16 at 12:59
Try to set `price_cents` rather that `price` to avoid conversion. — Aleksei Matiushkin, Jan 27 '16 at 13:05
Ok, I think that'll work. I guess the order is specific for dollar amounts. — Artem Kalinchuk, Jan 27 '16 at 13:07
As I have already said, the order is specific for those currencies, having not 2 decimals. For dollars everything should work as expected. — Aleksei Matiushkin, Jan 27 '16 at 13:08

score 1 · Answer 1 · answered Jan 27 '16 at 13:57

It looks like the order matters for certain currencies (including JPY because it doesn't have cents). This may not be the best solution but if anyone is stuck, here is what I did.

I added the following to the self.monetize method in money-rails to override the initialize methods for classes that use it:

define_method "initialize" do |opts = {}|
  opts = opts.deep_symbolize_keys
  opts = {currency: opts[:currency]}.merge(opts)
  super(opts)
end

This way it will send the currency first.

Money Rails - Order Of Amount And Currency

1 Answers1