gistfile1.rb

module LiquidPresenters
  class Plan < SimpleDelegator
    def to_liquid
      @to_liquid ||= HashWithIndifferentAccess.new({
        id: self.id,
        name: self.name,
        description: self.description,
        status: self.status,
        class_id: self.plan_class_id
      })
    end
  end
end

Liquid::Template.parse(template).render({
  'plan' => LiquidPresenters::Plan.new(Plan.last)
})