pivot_table_testing_daru.rb

require 'pivot_table'
require 'daru'

class Order
	attr_reader :city, :quarter, :top_sales
	def initialize args
		args.each do |k,v|
		  instance_variable_set("@#{k}", v) unless v.nil?
		end
	end
end

obj_1 = Order.new(city: 'London',   quarter: 'Q1', top_sales: 'Ed')
obj_2 = Order.new(city: 'London',   quarter: 'Q2', top_sales: 'Jim')
obj_3 = Order.new(city: 'London',   quarter: 'Q3', top_sales: 'Sam')
obj_4 = Order.new(city: 'London',   quarter: 'Q4', top_sales: 'Ed')
obj_5 = Order.new(city: 'New York', quarter: 'Q1', top_sales: 'Tom')
obj_6 = Order.new(city: 'New York', quarter: 'Q2', top_sales: 'Sandy')
obj_7 = Order.new(city: 'New York', quarter: 'Q3', top_sales: 'Phil')
obj_8 = Order.new(city: 'New York', quarter: 'Q4', top_sales: 'Jim')

data = [ obj_1, obj_2, obj_3, obj_4, obj_5, obj_6, obj_7, obj_8 ]

g = PivotTable::Grid.new do |g|
  g.source_data  = data
  g.column_name  = :quarter
  g.row_name     = :city
  g.value_name   = :sales
  g.field_name   = :top_sales
end

p g.build.data_grid == [['Ed' ,'Jim','Sam','Ed' ], ['Tom' ,'Sandy' ,'Phil','Jim' ]]

row_headers = g.row_headers
# p row_headers
data = g.rows.map {|gg| gg.data}
# p data
# p ""

headers = g.column_headers
# p headers
# p g.columns.map {|gg| gg.data}
# p ""

p Daru::Formatters::Table.format(data, headers: headers, row_headers: row_headers)
# output:
# => "                Q1       Q2       Q3       Q4\n   London       Ed      Jim      Sam       Ed\n New York      Tom    Sandy     Phil      Jim"