Simple Ruby on Rails 4 model with ElasticSearch query.

Crb.rb

require 'elasticsearch/model'

class Cbr
  include ActiveModel::Model
  include Elasticsearch::Model

  index_name    'cbr'
  document_type 'UC_CBR_003'

  # Digital Objects per day
  def self.do_per_day
    # begin ES query
    definition = Elasticsearch::DSL::Search.search do

      query do
        match_all do
        end
      end

      # minimal timestamp value
      aggregation :timestamp_min do
        min field: 'timestamp'
      end

      # maximal timestamp value
      aggregation :timestamp_max do
        max field: 'timestamp'
      end

      # sum DO per day
      aggregation :do_sum_per_day do
        date_histogram do
          field    'timestamp'
          interval 'day'
          format   'dd.MM. yyyy'

          aggregation :do_sum do
            sum field: 'pocet_do'
          end
        end
      end

    end
    # end ES query

    result = search definition.to_hash, search_type: 'count'
  end
end

do_controller.rb

class DoController < ApplicationController

  def report_1
    @data = {
      timestamp_min: 0,
      timestamp_max: 0,
      data: []
    }

    data = []
    Cbr.do_per_day.response['aggregations']['do_sum_per_day']['buckets'].each do |row|
      row = [
        row['key'],
        row['do_sum']['value']
      ]
      data.push(row)
    end

    @data['timestamp_min'] = Cbr.do_per_day.response['aggregations']['timestamp_min']['value']
    @data['timestamp_max'] = Cbr.do_per_day.response['aggregations']['timestamp_max']['value']
    @data['data'] = data

    @data = @data.to_json

    render 'reports/report'
  end
  
end