What is the best way to assign a resource to an attribute? about latinum HOT 5 OPEN

I found that I was able to do this with write_attribute(). But I would still like to know the canonical or expected usage.

from latinum.

I'm still using this gem and I suppose you could call it maintained, it's just been stable enough that no changes were required.

The following code was implemented for support of serialize:

A bank object is only needed for formatting and converting resources, it should not be needed for basic interactions with "I have X units of Y."

For actual values, you need to write:

entry.line_items.create!(amount: '40145.00 USD')

If you want rich input, you do need to use the bank configured with the currencies you want. Otherwise, how can you tell $5 is USD, NZD, AUD, etc.

In order to use the bank object, you should configure it in the controller to map the user input before creating the model with attribute values.

e.g.

params['amount'] = bank.parse(params['amount'])

I can write updated documentation with working examples if that helps.

from latinum.

I wonder if we should make Resource.load also check for Resource instances and return it directly to support the above use case if it isn't already handled by AR.

from latinum.

Okay, so with a few minor changes, we can make this work a bit more nicely:

Loading development environment (Rails 7.1.1)
irb(main):001> t = T.new
=> #<T:0x00007f2fb8b88ff0 id: nil, data: nil, amount: nil, created_at: nil, updated_at: nil>
irb(main):002> t.amount = "$5 USD"
=> "$5 USD"
irb(main):003> t.amount
=> #<Latinum::Resource "5.0 USD">

The code is:

require 'latinum/currencies/global'

class T < ApplicationRecord
  BANK = Latinum::Bank.new.tap do |bank|
    bank.import(Latinum::Currencies::Global)
  end
  
  serialize :amount, coder: BANK
end

This uses the bank as a coder, which accepts a wider range of inputs. However, if there is ambiguity, it is resolved according to the bank's internal priority, e.g. $ is used by several currencies.

from latinum.

I've released v1.8.0 with the required changes and added documentation: https://ioquatix.github.io/latinum/guides/activerecord-integration/index.html

from latinum.