gistfile1.rb

class ProjectSerializer < ActiveModel::Serializer
  attributes :id, :title, :status, :owner, :description, :created_at, :updated_at, :cover_image_url, :cover_image_thumb_url, :cover_image_show_url

  def cover_image_thumb_url
    object.cover_image.url(:thumb)
  end

  def cover_image_show_url
    object.cover_image.url(:show)
  end

  def cover_image_url
    object.cover_image.url()
  end
end