Custom Ruby CSV converters for multiple fields

Question

I am importing a CSV file that contains fields that need to be converted as follows:

• "True" (string) -> true (boolean)
• "False" (string) -> false (boolean)
• "%m/%d/%Y" (string format) -> Date object
• "%m/%d/%Y %I:%M:%S %p" (string format) -> DateTime object

The default CSV converters don't match the Date and DateTime fields. This method below seems to work, but wonder if there is a better way, possibly by override the matching pattern used by the converters?

 require 'csv'
 require 'date'

 src = <<csv
 active,date_created,date_modified
 "True","03/12/2012","03/12/2012 2:14:23 PM"
 "False","01/25/2011","03/12/2013 3:14:27 AM"
 csv

 CSV::Converters[:my_converters] = lambda{|field| 
   begin 
     case field.to_s
       when "True"
         true
       when "False"
         false
       when /^\d{2}\/\d{2}\/\d{4}$/
         Date.strptime(field,"%m/%d/%Y")
       else
         DateTime.strptime(field,"%m/%d/%Y %I:%M:%S %p")
       end
   rescue ArgumentError
     field
   end
 }

 csv = CSV(src, :headers => true, :converters => [:my_converters])
 csv.each{|row| puts row}

true,2012-03-12,2012-03-12T14:14:23+00:00

false,2011-01-25,2013-03-12T03:14:27+00:00

Answer 1

Convert fields accordingly field's name (header's name)

custom_converter = lambda { |value, field_info|
  case field_info.header
  when 'OrderUuid', 'Exchange', 'Type', 'OrderType'
    value.to_s
  when 'Quantity', 'Limit', 'CommissionPaid', 'Price'
    value.to_f
  when 'Opened', 'Closed'
    Time.zone.parse(value)
  else
    fail("Unknown field name #{field_info.inspect}=#{value}")
  end
}

CSV.parse(content, headers: :first_row, converters: [custom_converter]).map(&:to_h)