Perforated Serializer

perforated_serializer.rb

require 'readthis/expanders'
require 'perforated'

class PerforatedSerializer
  attr_reader :relation, :scope, :serializer, :options

  def initialize(relation, options = {})
    @relation   = relation
    @scope      = options.fetch(:scope)
    @serializer = options.fetch(:each_serializer)
    @options    = options
  end

  def to_json(opts = {})
    cached(opts).to_json(opts) do |model|
      serializer.new(model, options)
    end
  end

  def cached(opts = {})
    if relation.any?
      Perforated.new(relation, KeyStrategy.new(scope, opts))
    else
      opts[:rooted] ? {} : []
    end
  end

  private

  class KeyStrategy
    attr_reader   :scope
    attr_accessor :rooted

    def initialize(scope, rooted: false)
      @scope  = scope
      @rooted = rooted
    end

    def expand_cache_key(object)
      args = [scope.role]
      args << 'rooted' if rooted

      if object.respond_to?(:object) && !object.respond_to?(:cache_key)
        args.unshift(object.object)
      else
        args.unshift(object)
      end

      Readthis::Expanders.expand_key(args)
    end
  end
end

submissions_controller.rb

class V3::SubmissionsSerializer < Api::ApiController
  def index
    render json: PerforatedSerializer.new(
      submission_query.submissions.paginate(paginatation_params),
      scope: current_user,
      root: 'submissions',
      each_serializer: serializer
    ).to_json(rooted: true)
  end
end