Contents

require "active_support"

module Hexx

  # Module defines:
  #
  # * <tt>validate!</tt> public instance method
  # * +attr_coerced+ public class methods.
  #
  # Include the module into the Rails model:
  #
  #   require "hexx"
  #   require_relative "attributes/string"
  #
  #   class User < ActiveRecord::Base
  #     include Hexx::Models
  #
  #     # coerces attributes
  #     attr_coerced :name, login, type: Attributes::String
  #   end
  #
  module Models
    extend ActiveSupport::Concern

    # Runs validations and raises a RecordInvalid exceptions in case of
    # an invalid case.
    def validate!
      return true if valid?
      fail RecordInvalid.new self
    end

    # Model class helpers for attributes coercion.
    module ClassMethods

      def attr_coerced(*names, type:)
        names.each { |name| _attr_coerced(name, type) }
      end

      private

      def _attr_coerced(name, type)
        if ancestors.map(&:name).include? "ActiveRecord::Base"
          coerce_activerecord_reader name, type
          coerce_activerecord_writer name, type
        else
          coerce_simple_reader name, type
          coerce_simple_writer name, type
        end
      end

      def coerce_simple_reader(name, type)
        class_eval(
          "def #{ name };
            #{ type.name }.new(@#{ name });
          end"
        )
      end

      def coerce_simple_writer(name, type)
        class_eval(
          "def #{ name }=(value);
            @#{ name } = #{ type.name }.new(value);
          end"
        )
      end

      def coerce_activerecord_reader(name, type)
        class_eval(
          "def #{ name };
            #{ type.name }.new read_attribute(:#{ name });
          end"
        )
      end

      def coerce_activerecord_writer(name, type)
        class_eval(
          "def #{ name }=(value);
            write_attribute :#{ name }, #{ type.name }.new(value);
          end"
        )
      end
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
hexx-0.1.1	lib/hexx/models.rb
hexx-0.1.0	lib/hexx/models.rb