Module: HasConstant::ClassMethods

Defined in:
lib/has_constant.rb

Overview

HasConstant takes a Proc containing an array of possible values for a field name The field name is inferred as the singular of the has constant name. For example has_constant :titles would use the database column “title”

USAGE:

class User < ActiveRecord::Base

include HasConstant
has_constant :titles, lambda { %w(Mr Mrs) }

end

User.titles #=> [‘Mr’, ‘Ms’]

@user.attributes #=> 0

@user.title_is?(‘Mr’) #=> true @user.title_is?(‘Ms’) #=> false

User.by_constant(‘title’, ‘Mr’) #=> [@user]

Instance Method Summary collapse

Instance Method Details

#has_constant(name, values = lambda { I18n.t(name) }, options = {}) ⇒ Object 



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# File 'lib/has_constant.rb', line 41

def has_constant(name, values = lambda { I18n.t(name) }, options = {})
  singular = (options[:accessor] || name.to_s.singularize).to_s

  (class << self; self; end).instance_eval do
    define_method(name.to_s, values) if values.respond_to?(:call)
    define_method(name.to_s, lambda { values }) unless values.respond_to?(:call)
  end

  define_method(singular) do
    values[instance_variable_get("@#{singular}")]
  end

  # Add the setter method. This takes the string representation and converts it to an integer to store in the DB
  define_method("#{singular}=") do |val|
    if val.instance_of?(String)
      if values.index(val)
        instance_variable_set("@#{singular}", values.index(val))
      else
        raise ArgumentError,
          "value for #{singular} must be in #{self.class.send(name.to_s).join(', ')}"
      end
    else
      instance_variable_set("@#{singular}", val)
    end
  end

  define_method("#{singular}_is?") do |value|
    truth = send(singular) == value.to_s
    if !truth && I18n.locale.to_s != 'en'
      truth = I18n.with_locale(:en) { send(singular) == value.to_s }
    end
    truth
  end

  define_method("#{singular}_is_not?") do |value|
    !send("#{singular}_is?", value)
  end

  define_method("#{singular}_in?") do |value_list|
    truth = value_list.include? send(singular)
    if !truth && I18n.locale.to_s != 'en'
      truth = I18n.with_locale(:en) { value_list.include?(send(singular)) }
    end
    truth
  end

  define_method("#{singular}_not_in?") do |value_list|
    !send("#{singular}_in?", value_list)
  end
end