Module: ActiveRecord::Acts::Constant::ClassMethods

Defined in:
lib/acts_as_constant.rb

Instance Method Summary collapse

Instance Method Details

#acts_as_constant(col = :name) ⇒ Object 



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# File 'lib/acts_as_constant.rb', line 10

def acts_as_constant(col = :name)
  begin
    #puts self.to_s
    
    # let's set up a variable to represent the name of the klass
    klass = self.to_s
    #puts "klass = #{klass}"
    const = klass.upcase.gsub("::", "_")
    #puts "const = #{const}"
    
    define_method("constantize") do
      self.send(col).constantize
    end
    
    class_eval %{
      def self.constant_class_name
        "#{const}"
      end
      
      def self.constant_column
        "#{col}"
      end
    }
    
    # create a constant array to hold the values
    # create a nice get method to pull from the constant array
    class_eval %{
      private
      #{self.constant_class_name}_CONSTANTS = []
      
      public
      def self.get(id)
        return nil if id.blank?
        #{self.constant_class_name}_CONSTANTS[id]
      end
      
      def self.CONSTANTS
        #{self.constant_class_name}_CONSTANTS
      end

    }
    
    class_eval do
      def self.reload_constants!
        begin
          self.CONSTANTS.clear
          
          rows = eval "#{self.to_s}.find(:all)"

          rows.each do |rec|
            #puts rec.inspect
            name = rec.send(self.constant_column)

            unless name.nil?

              # let's sanitize the name a bit.
              name = name.underscore.gsub("/", '_')

              self.instance_eval do

                define_method("constant_name") do
                  self.send(self.constant_column).downcase.gsub(' ', '_')
                end

              end                                                                        

              # let's create two methods an all downcase method for accessing the constant and an upper case one
              class_eval %{
                # by using .freeze we can prevent the object from being modified.
                #{self.constant_class_name}_CONSTANTS[#{rec.id}] = rec.freeze

                def self.#{name}
                  #{self.constant_class_name}_CONSTANTS[#{rec.id}]
                end

                def self.#{name.upcase}
                  #{self.constant_class_name}_CONSTANTS[#{rec.id}]
                end
              }
            end
          end
        rescue Exception => e
          
        end
        
      end
    end
    
    self.reload_constants!
    
  rescue => ex
    #puts "Error in acts_as_constant: #{ex.message}"
    #puts ex.backtrace
  end
  
end