Module: EnumField::ClassMethods

Defined in:
lib/enum_field.rb

Instance Method Summary collapse

Instance Method Details

#enum_field(field, possible_values, options = {}) ⇒ Object

enum_field encapsulates a validates_inclusion_of and automatically gives you a few more goodies automatically.

class Computer < ActiveRecord:Base
  enum_field :status, ['on', 'off', 'standby', 'sleep', 'out of this world']

  # Optionally with a message to replace the default one
  # enum_field :status, ['on', 'off', 'standby', 'sleep'], :message => "incorrect status"

  #...
end

This will give you a few things:

  • add a validates_inclusion_of with a simple error message (“invalid #field”) or your custom message

  • define the following query methods, in the name of expressive code:

    • on?

    • off?

    • standby?

    • sleep?

    • out_of_this_world?

  • define the STATUSES constant, which contains the acceptable values



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# File 'lib/enum_field.rb', line 29

def enum_field(field, possible_values, options={})
  message = options[:message] || I18n.translate('activerecord.errors.messages.invalid')
  const_set field.to_s.pluralize.upcase, possible_values unless const_defined?(field.to_s.pluralize.upcase)
  
  possible_values.each do |current_value|
    method_name = current_value.downcase.gsub(/[-\s]/, '_')
    define_method("#{method_name}?") do
      self.send(field) == current_value
    end
  end
  
  validates_inclusion_of field, :in => possible_values, :message => message
end