Rails Responder

gistfile1.rb

class CreditCardController < ApplicationController
  def create
    creator = CreditCardCreator.call(params)
    # creator.respond_to?(:errors) => true
    # creator.errors => [] (by default)
    # when something goes wrong: creator.errors => ['Terrible Error']
    respond_with(creator)
  end
end

# Also sets the proper responses
# Success looks like { expiration_date: '2014-10-10', ... }
# Errors look like { errors: ['Terrible Error'] }

class Grouper::ServiceObject
  def errors
    @errors ||= []
  end
end

class CreditCardCreator < Grouper::ServiceObject
  def call(params)
    card = CreditCard.new(params)
    unless card.save
      @errors = card.errors
      return false
    end
    ...
    response = Stripe.create_card(data)
    
    unless response.success?
      self.errors << response.error_message
      return false
    end
    
    return true
  end
end

I was assuming CreditCardCreator.call(params) returned an instance of CreditCardCreator

all this really does is shift code around and introduce more indirection. It also requires/encourages service objects with mutable state.

not a fan of respond_with, either - it's yet more indirection that relies on opaque conventions about object state to magically produce the various HTTP responses.