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# the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

module Elasticsearch
  module DSL
    module Search
      module Filters

        # A filter which returns documents which have a non-`null` value in the specified field
        # (ie. the reverse of the `missing` filter)
        #
        # @example
        #
        #     search do
        #       query do
        #         filtered do
        #           filter do
        #             exists field: 'occupation'
        #           end
        #         end
        #       end
        #     end
        #
        # @see http://elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-exists-filter.html
        #
        class Exists
          include BaseComponent

          option_method :field
        end

      end
    end
  end
end
