Setting currency with form select with Money gem

Question

I have been working quite a few hours on this one but I can't figure out this one.

I am willing to have the user select a corresponding currency for the price he is filling in the form.

I am using the Money Gem (https://github.com/RubyMoney/money ). All values are set correctly BUT not the currency that only sets to its default value (USD) whatever is sent through the form. I suppose this is my lack of experience with the Money gem.

In My Model:

 require 'money'
  composed_of :price_per_unit,
    :class_name => "Money",
    :mapping => [%w(cents_per_unit cents), %w(currency currency_as_string)],
    :constructor => Proc.new { |cents_per_unit, currency| Money.new(cents_per_unit || 0, currency || Money.default_currency) },
    :converter => Proc.new { |value| value.respond_to?(:to_money) ? value.to_money :  raise(ArgumentError, "Can't convert #{value.class} to Money") }

  composed_of :total_price,
    :class_name => "Money",
    :mapping => [%w(cents cents), %w(currency currency_as_string)],
    :constructor => Proc.new { |cents, currency| Money.new(cents || 0, currency ||  Money.default_currency) },
    :converter => Proc.new { |value| value.respond_to?(:to_money) ? value.to_money : raise(ArgumentError, "Can't convert #{value.class} to Money") }

:price_per_unit and :total_price share in common the :currency attribute.

:price_per_unit working with cents_per_unit and currency :total_price working with cents and currency

In my controller:

  def new
     @power_plant_substrate = PowerPlantSubstrate.new

     # preparing the form select for the currencies
     @currencies = [] 
     major_currencies(Money::Currency::TABLE).each do |currency|  
       name = Money::Currency::TABLE[currency][:name]
       iso_code = Money::Currency::TABLE[currency][:iso_code]
       @currencies << [name, iso_code]
     end
  end

In my new form view:

      <p>
        <%= f.select(:currency, @currencies) %>
      </p>
      <p>
        <%= f.label :price_per_unit %>
        <%= f.number_field :price_per_unit, :size => 5, :value => 0, :step => 0.01, :min => 0 %> 
      </p>
      <p>
        <%= f.label :total_price %>
        <%= f.number_field :total_price, { :step => 1, :size => 10, :value => 0 } %> 
      </p>

I did try changing the default currency to AUD, then all my records get set to AUD whatever my pick in my select.

In my log:

Started POST "/power_plant_substrates" for 127.0.0.1 at 2011-11-03 00:40:38 +0100
  Processing by PowerPlantSubstratesController#create as JS
  Parameters: {"utf8"=>"✓", "feedstock"=>"", "power_plant_substrate"=>{"power_plant_id"=>"59", "substrate_id"=>"159", "quantity"=>"1", "trade"=>"selling", "currency"=>"JPY", "price_per_unit"=>"1.00", "total_price"=>"1", "address"=>"Pélussin, France", "transport"=>"pickup_only", "latitude"=>"", "longitude"=>"", "description"="sadf"}, "commit"=>"Save"}
  User Load (0.3ms)  SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1  [["id", 21]]
  PowerPlant Load (0.3ms)  SELECT "power_plants".* FROM "power_plants" WHERE "power_plants"."user_id" = 21 AND "power_plants"."name" = 'My Tradings' LIMIT 1
  SQL (0.7ms)  INSERT INTO "power_plant_substrates" ("address", "cents", "cents_per_unit", "created_at", "currency", "description", "gmaps", "latitude", "locale", "longitude", "period","power_plant_id", "quantity", "state", "substrate_id", "trade", "transport","unit_of_measure", "updated_at") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,?, ?, ?, ?, ?)  [["address", "Pélussin, France"], ["cents", 100], ["cents_per_unit", 100], ["created_at", Wed, 02 Nov 2011 23:40:39 UTC +00:00], ["currency", "CAD"], ["description", "sadf"], ["gmaps", true], ["latitude", 45.417608], ["locale", "us"], ["longitude", 4.676041], ["period", "year"], ["power_plant_id", 59], ["quantity", 1], ["state", "open"], ["substrate_id", 159], ["trade", "selling"], ["transport", "pickup_only"], ["unit_of_measure", "mass"], ["updated_at", Wed, 02 Nov 2011 23:40:39 UTC +00:00]]
Completed 200 OK in 1107ms (Views: 4.3ms | ActiveRecord: 2.5ms)

Any ideas?

Cheers,

Joël

Answer 1

SOLVED!!

Solved by adding one line in create method :

def create
    @power_plant_substrate = PowerPlantSubstrate.new(params[:power_plant_substrate])

    # here I am setting the currency with what was sent in params
    @power_plant_substrate.currency = params[:power_plant_substrate][:currency] <=== this line

...

end