Module: Plutonium::Models::HasCents::ClassMethods

Defined in:
lib/plutonium/models/has_cents.rb

Instance Method Summary collapse

Instance Method Details

#has_cents(cents_name, name: nil, rate: 100, suffix: "amount", unit: nil) ⇒ Object

super(*args, options, &block) end Defines getter and setter methods for a monetary value stored as cents, and ensures validations are applied to both cents and decimal attributes.

Examples:

Standard currency (dollars and cents)

has_cents :price_cents

Static currency symbol

has_cents :price_cents, unit: "£"

Per-row currency symbol read off the record

has_cents :price_cents, unit: :currency_symbol

Custom rate for a different currency division

has_cents :amount_cents, name: :cost, rate: 1000

Whole number storage without decimal places

has_cents :quantity_cents, name: :quantity, rate: 1

Using custom suffix

has_cents :total_cents, suffix: "value"

Parameters:

  • cents_name (Symbol) —

    The name of the attribute storing the cents value.

  • name (Symbol, nil) (defaults to: nil) —

    The name for the generated methods. If nil, it's derived from cents_name.

  • rate (Integer) (defaults to: 100) —

    The conversion rate from the decimal value to cents (default: 100). This represents how many cents are in one unit of the decimal value. For example:

    • rate: 100 for dollars/cents (1 dollar = 100 cents)
    • rate: 1000 for dollars/mils (1 dollar = 1000 mils)
    • rate: 1 for a whole number representation
  • suffix (String) (defaults to: "amount") —

    The suffix to append to the cents_name if name is not provided (default: "amount").

  • unit (String, Symbol, nil) (defaults to: nil) —

    The currency unit used when the value is rendered as currency. A String is used verbatim as the symbol ("£"); a Symbol names a method read off the record for per-row currencies (unit: :currency_symbol); nil (default) renders with no symbol. Consumers (the Currency display component, grid/kanban cards) read this via Plutonium::Models::HasCents#has_cents_unit_for.



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# File 'lib/plutonium/models/has_cents.rb', line 152

def has_cents(cents_name, name: nil, rate: 100, suffix: "amount", unit: nil)
  cents_name = cents_name.to_sym
  name ||= cents_name.to_s.gsub(/_cents$/, "")
  name = name.to_sym
  name = (name == cents_name) ? :"#{cents_name}_#{suffix}" : name

  self.has_cents_attributes = has_cents_attributes.merge(
    cents_name => {name: name, rate: rate, unit: unit}
  )

  class_eval <<-RUBY, __FILE__, __LINE__ + 1
    # Getter method for the decimal representation of the cents value.
    #
    # @return [BigDecimal, nil] The decimal value or nil if cents_name is not present.
    def #{name}
      #{cents_name}.to_d / #{rate} if #{cents_name}.present?
    end

    # Setter method for the decimal representation of the cents value.
    #
    # @param value [Numeric, nil] The decimal value to be set.
    def #{name}=(value)
      self.#{cents_name} = begin
        (BigDecimal(value.to_s) * #{rate}).to_i if value.present?
      rescue ArgumentError
        nil
      end
    end

    # Mark decimal field as invalid if cents field is not valid
    after_validation do
      next unless errors[#{cents_name.inspect}].present?

      errors.add(#{name.inspect}, :invalid)
    end
  RUBY
end

#has_cents_attribute?(attribute) ⇒ Boolean

Checks if a given attribute is defined with has_cents

Parameters:

  • attribute (Symbol) —

    The attribute to check

Returns:

  • (Boolean) —

    true if the attribute is defined with has_cents, false otherwise



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# File 'lib/plutonium/models/has_cents.rb', line 194

def has_cents_attribute?(attribute)
  has_cents_attributes.key?(attribute.to_sym)
end

#has_cents_decimal_attribute?(attribute) ⇒ Boolean

Checks if a given attribute is the decimal accessor of a has_cents pair (e.g. :amount for has_cents :amount_cents).

Parameters:

  • attribute (Symbol) —

    The attribute to check

Returns:

  • (Boolean) 


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# File 'lib/plutonium/models/has_cents.rb', line 203

def has_cents_decimal_attribute?(attribute)
  attribute = attribute.to_sym
  has_cents_attributes.any? { |_, opts| opts[:name] == attribute }
end