How to validate in a model, data from a controller

Question

So I have some data that gets pulled from another rails app in a controller lets call it ExampleController and I want to validate it as being there in my model before allowi

Answer 1

The only way to share controller level data with model is through external accessor. Using metaprogramming you can trick the way to pass it to a model instance.

controller

def valid_data?            
  data = #data could be nil or not
  result = data.blank? ? false : true
  instance_eval <<-EOV
    def AWizard.new(*args)
      super(*args).tap {|aw| aw.external_valid = #{result}}
    end
  EOV
  result
end

model

class AWizard
  attr_accessor :external_valid

  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end

  validate :first_step_data, :if => lambda { |o| o.current_step == "step1" };

  def first_step_data
    # :external_valid would be true or false according to a valid_data?. Nil would be if valid_data? has not been called
    if external_valid == false
      errors.add ...
    end
  end
end