array_serializer.rb

class ArraySerializer
  def initialize(objects, *args)
    @objects = objects
  end

  def to_json
    serializable_array.to_json.html_safe
  end

  def serializable_array
    @objects.map do |o|
      serializer.new(o).serializable_hash
    end
  end

  def serializer
    @serializer ||= "#{@objects.first.class}Serializer".constantize
  end
end

example.rb

location = Location.first
location_json = LocationSerializer.new(location).to_json

locations = Locations.first(25)
locations_json = ArraySerializer.new(locations).to_json

location_serializer.rb

class LocationSerializer < BaseSerializer
  def initialize(object)
    @object = object
  end

  def to_json
    serializable_hash.to_json.html_safe
  end

  def serializable_hash
    Hash.new.tap do |data|
      data[:id]        = @object.id.to_i
      data[:name]      = @object.handle
      data[:parent_id] = @object.parent_id unless @object.parent_id.blank?

      data[:descendant_ids]  = @object.descendants.published.map(&:id)

      data[:addresses] = @object.addresses.map do |address|
        AddressSerializer.new(address).serializable_hash
      end

      data[:url]         = @object.public_path
      data[:thumbnail]   = "//www.scripps.org/#{@object.image.portrait_thumbnail_url}" if @object.image
    end
  end
end