Contents

# frozen_string_literal: true

#
# Copyright (c) 2020-present, Blue Marble Payroll, LLC
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
#

module Burner
  module Library
    module Collection
      # Take an array of objects and un-pivot groups of keys into rows.
      # Under the hood it uses HashMath's Unpivot class:
      # https://github.com/bluemarblepayroll/hash_math
      #
      # Expected Payload[register] input: array of objects.
      # Payload[register] output: An array of objects.
      class Unpivot < JobWithRegister
        attr_reader :unpivot

        def initialize(
          name: '',
          pivot_set: HashMath::Unpivot::PivotSet.new,
          register: DEFAULT_REGISTER
        )
          super(name: name, register: register)

          @unpivot = HashMath::Unpivot.new(pivot_set)

          freeze
        end

        def perform(output, payload)
          payload[register] = array(payload[register])
          object_count      = payload[register].length || 0

          message = "#{pivot_count} Pivots, Key(s): #{key_count} key(s), #{object_count} objects(s)"

          output.detail(message)

          payload[register] = payload[register].flat_map { |object| unpivot.expand(object) }
        end

        private

        def pivot_count
          unpivot.pivot_set.pivots.length
        end

        def key_count
          unpivot.pivot_set.pivots.map { |p| p.keys.length }.sum
        end
      end
    end
  end
end

Version data entries

8 entries across 8 versions & 1 rubygems

Version	Path
burner-1.12.0	lib/burner/library/collection/unpivot.rb
burner-1.11.0	lib/burner/library/collection/unpivot.rb
burner-1.10.0	lib/burner/library/collection/unpivot.rb
burner-1.9.0	lib/burner/library/collection/unpivot.rb
burner-1.9.0.pre.alpha	lib/burner/library/collection/unpivot.rb
burner-1.8.0	lib/burner/library/collection/unpivot.rb
burner-1.7.0	lib/burner/library/collection/unpivot.rb
burner-1.7.0.pre.alpha	lib/burner/library/collection/unpivot.rb