Fragment Caching

fragment_caching.rb

def key_for(namespace, *objects)
    object_collection = []

    objects.each do |object|
      if object.respond_to? :pluck
        object_ids = object.pluck(:id).join '-'
        max_updated_at = object.pluck(:updated_at).max.to_s
      elsif object.respond_to? :id
        object_ids = object.id
        max_updated_at = object.respond_to?(:updated) ? object.updated : object.updated_at
      elsif object.respond_to? :map
        object_ids = object.map(&:id).join '-'
        max_updated_at = object.map(&:updated).max
      elsif object.is_a? String
        object_ids = object
        max_updated_at = 'not found'
      elsif object.nil?
        fail 'error caching because the object is nil.'
      else
        fail 'error caching.'
      end

      object_collection << "#{object_ids}-#{max_updated_at}"
    end

    result = namespace
    result << '/' + object_collection.join('/') unless object_collection.empty?

    result.to_s.gsub(/(?:\+|:| )/, '-')
  end