total_entries ||= nil
current_page_entries ||= 0
collection ||= nil

# Looking for object with pagination if pages count not set
if total_entries.nil? and current_page_entries==0

  # looking for the right collection if not initiated via parameter
  if collection.nil?
    instance_variables.each do |vn|
      v = instance_variable_get(vn)
  
      # if a collection variable was specified, use it only
      next if collection && collection != v
      next if v.class.name.nil?

      collection = v if v.class.name.start_with?("MetaSearch::Searches", "ActiveRecord::Relation", "Mongoid::Criteria")
    end
  end

  # receiving correct current page entries count
  current_page_entries = collection.size if collection.respond_to?('size')

  # looking for the total entries count
  total_entries = collection.length if collection.class.name.start_with?("Mongoid::Criteria")
  total_entries = collection.total_entries if collection.respond_to?('total_entries')

  # fallback to 1 page if total entries count not found
  total_entries = current_page_entries if total_entries.nil?
end

json.iTotalRecords current_page_entries
json.iTotalDisplayRecords total_entries
json.sEcho params["sEcho"].to_i
json.aaData do
  json.ingest! yield
end