Base class type for entity classes in ruby

base_type.rb

# frozen_string_literal: true

require "json"
require "nokogiri"

module Types
  class BaseType
    def to_hash
      hash = {}

      instance_variables_hash.each do |key, value|
        parameter = key.to_s.delete('@')
        hash[parameter.to_sym] = value
      end

      hash
    end

    def from_hash(hash)
      obj = self.class.new

      hash.each do |key, value|
        parameter = "@#{key}"
        obj.instance_variable_set(parameter, value)
      end

      obj
    end

    def to_json
      instance_variables_hash.to_json
    end

    def from_json(json_string)
      data = JSON.parse(json_string)
      obj = self.class.new

      data.each do |key, value|
        obj.instance_variable_set("@#{key}", value)
      end

      obj
    end

    def to_xml
      builder = Nokogiri::XML::Builder.new do |xml|
        xml.send(self.class.name.downcase) {
          instance_variables_hash.each do |key, value|
            parameter = key.to_s.delete('@')

            xml.send(parameter) {
              xml.text(value)
            }
          end
        }
      end

      builder.to_xml
    end

    def from_xml(xml_string)
      data = Nokogiri::XML.parse(xml_string)
      obj = self.class.new

      data.root.children.each do |node|
        next unless node.element?

        parameter = "@#{node.name}"
        value = node.text
        obj.instance_variable_set(parameter, value)
      end

      obj
    end

    def to_html
      html = "<div><ul>"

      instance_variables_hash.each do |key, value|
        parameter = key.to_s.delete('@').capitalize
        html << "<li>#{parameter}: #{value}</li>"
      end

      html << "</ul></div>"

      html
    end

    def to_html_form
      html = "<form>"

      instance_variables_hash.each do |key, value|
        parameter = key.to_s.delete('@')
        html << "<label for='#{parameter}'>#{parameter.capitalize}:</label>"
        html << "<input type='text' id='#{parameter}' name='#{parameter}' value='#{value}'><br>"
      end

      html << "</form>"

      html
    end

    private

    def instance_variables_hash
      hash = {}

      instance_variables.each { |var| hash[var] = instance_variable_get(var) }

      hash
    end
  end
end