Module: EasyRailsMoney::ActiveRecord::MoneyDsl::ClassMethods

Defined in:
lib/easy_rails_money/active_record/money_dsl.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#single_currency ⇒ Object

Returns the value of attribute single_currency.



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# File 'lib/easy_rails_money/active_record/money_dsl.rb', line 10

def single_currency
  @single_currency
end

Instance Method Details

#money(column_name) ⇒ Object 



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# File 'lib/easy_rails_money/active_record/money_dsl.rb', line 48

def money column_name
  money_column = "#{column_name}_money"
  currency_column = "#{column_name}_currency"
  single_currency_column = "currency"
  
  if single_currency?
    define_method column_name do |*args|
      money = send(money_column)
      currency = send(single_currency_column)
      
      if money
        Money.new(money, currency)
      else
        nil
      end
    end

    define_method "#{column_name}=" do |value|
      raise ::ArgumentError.new("only Integer or nil accepted") unless (value.kind_of?(Integer) || value.is_a?(NilClass))
      
      send("#{money_column}=", value)
      # currency is stored in a seperate common column
      return Money.new(value, self.currency)
    end # define_method setter
  else
    # TODO: test if Memoization will make any difference
    define_method column_name do |*args|
      money = send(money_column)
      currency = send(currency_column) || EasyRailsMoney.default_currency
      
      if money
        Money.new(money, currency)
      else
        nil
      end
    end
    
    define_method "#{column_name}=" do |value|
      raise ::ArgumentError.new("only Money or nil accepted") unless (value.kind_of?(Money) || value.is_a?(NilClass))
      
      if value
        send("#{money_column}=", value.fractional)
        # it is stored in the database as a string but the Money
        # object exposes it as a Symbol. so we store it as a
        # String for consistency
        send("#{currency_column}=", value.currency.id.to_s)
        return value
      else
        send("#{money_column}=", nil)
        send("#{currency_column}=", nil)
        return nil
      end
    end # define_method setter
  end
end

#new(attributes = nil, options = {}) ⇒ Object 



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# File 'lib/easy_rails_money/active_record/money_dsl.rb', line 35

def new(attributes = nil, options = {})
  instance = super
  # single currency is defined
  if single_currency?
    if attributes && attributes[:currency]
      instance.currency = EasyRailsMoney::MoneyDslHelper.to_currency(attributes[:currency]).id.to_s
    else
      instance.currency = instance.class.single_currency
    end
  end
  instance
end

#single_currency? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/easy_rails_money/active_record/money_dsl.rb', line 12

def single_currency?
  # if we define a ActiveRecord object with a money column
  # "before" the table is defined. Then it will throw an error
  # and we will assume that a single currency is defined
  # So always restart the app after the migrations are run
  self.columns_hash.has_key? "currency"
rescue Object => err
  # leaky abstaction. database adapter is leaking through
  # postgres with activerecord throws an error of type PG::Error and sqlite of ActiveRecord::StatementInvalid
  # so we depend on the message, not the class. still need to test on other
  # database adapters because the message is not exactly the same
  if err.message =~ /Could not find table/ || err.message =~ /relation (.+) does not exist/
    return true
  else
    raise
  end
end

#with_currency(currency, &block) ⇒ Object 



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# File 'lib/easy_rails_money/active_record/money_dsl.rb', line 30

def with_currency currency, &block
  self.single_currency = EasyRailsMoney::MoneyDslHelper.to_currency(currency).id.to_s
  instance_eval &block
end