Question

theres an excerpt of my code:

module Configuracao
  extend self

  class Key
    include ActiveModel::Validations
    attr_accessor :name, :type, :default, :validations, :group, :available_values

    def initialize(params)
      params.symbolize_keys!.assert_valid_keys(:name, :type, :default, :validations, :group, :available_values)
      @group = params[:group]
      @name = params[:name]
      @type = params[:type]
      @available_values = params[:available_values]
      @default = params[:default]
      @validations = params[:validations]

      #in this way each validation is being added for all keys
      Configuracao::Key.class_eval do
        validates :value, params[:validations]
      end
    end
  end
end

so for every instance key i will have a diferent validation passed in a hash, example:

Key.new( validations: { presence: true, numericality: true } )
Key.new( validations: { length: { maximum: 30 } } )

There’s a way to do it?

Answer 1

well i found a solution, maybe not so elegant or best way to do, but it works

def initialize(params)
  params.symbolize_keys!.assert_valid_keys(:name, :type, :default, :validations, :group, :available_values)
  @group = params[:group]
  @name = params[:name]
  @type = params[:type]
  @available_values = params[:available_values]
  @default = params[:default]
  @@current_validations = nil
  @@current_validations = @validations = params[:validations]

  class << self
    validates :value, @@current_validations unless @@current_validations.blank?
  end
end

now each time i instantiate a Key, the class will be modified only for that instance