class Postkode

Handles validation of UK-style postcodes

Constants

A1

Validating UK Postcodes Correct as at 2014-09-15 References below www.gov.uk/government/uploads/system/uploads/attachment_data/file/283357/ILRSpecification2013_14Appendix_C_Dec2012_v1.pdf en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom#Validation Areas with only single-digit districts: BR, FY, HA, HD, HG, HR, HS, HX, JE,

LD, SM, SR, WC, WN, ZE (although WC is always subdivided by a
further letter, e.g. WC1A).

Areas with only double-digit districts: AB, LL, SO. Areas with a district '0' (zero): BL, BS, CM, CR, FY, HA, PR, SL, SS (BS is

the only area to have both a district 0 and a district 10).

The following central London single-digit districts have been further

divided by inserting a letter after the digit and before the space:
EC1-EC4 (but not EC50), SW1, W1, WC1, WC2, and part of E1 (E1W),
N1 (N1C and N1P), NW1 (NW1W) and SE1 (SE1P).

The letters QVX are not used in the first position. The letters IJZ are not used in the second position. The only letters to appear in the third position are ABCDEFGHJKPSTUW when

the structure starts with A9A.

The only letters to appear in the fourth position are ABEHMNPRVWXY when

the structure starts with AA9A.

The final two letters do not use the letters CIKMOV, so as not to resemble

digits or each other when hand-written.

Post code sectors are one of ten digits: 0 to 9 with 0 only used once 9

has been used in a post town, save for Croydon and Newport (above).

A2

A3

A4

A5

AAN

AANA

AANN

AN

ANA

ANN

N

NORMAL_PART_POSTCODE_PATTERN

NORMAL_POSTCODE_PATTERN

NORMAL_POSTCODE_RE

NORMAL_POSTCODE_VALID

PART_ONE

PART_TWO

Public Class Methods

find_in_string(string) click to toggle source

# File lib/postkode.rb, line 73
def self.find_in_string(string)
  res = string.upcase.scan(NORMAL_POSTCODE_PATTERN)
  res.length > 0 ? res : nil
end

find_partial_in_string(string) click to toggle source

# File lib/postkode.rb, line 78
def self.find_partial_in_string(string)
  res = string.upcase.scan(NORMAL_PART_POSTCODE_PATTERN)
  res.length > 0 ? res : nil
end

get_first_section(string) click to toggle source

# File lib/postkode.rb, line 59
def self.get_first_section(string)
  get_outcode(string)
end

get_inward(string) click to toggle source

# File lib/postkode.rb, line 68
def self.get_inward(string)
  found = Postkode.validate(string, true)
  found ? found[1] : nil
end

get_outcode(string) click to toggle source

# File lib/postkode.rb, line 63
def self.get_outcode(string)
  found = Postkode.validate(string, true)
  found ? found[0] : nil
end

random() click to toggle source

# File lib/postkode.rb, line 91
def self.random()
  generator_pattern = "#{[AANN, AANA, ANA, ANN, AAN, AN].sample} #{PART_TWO}"
  StringRandom.random_regex(generator_pattern)
end

validate(string, return_parts = false) click to toggle source

# File lib/postkode.rb, line 51
def self.validate(string, return_parts = false)
  return false if string.nil? || string == '' || string == false
  result = string.match(NORMAL_POSTCODE_RE)
  return false if result.nil?

  return_parts ? result[1..2] : true
end

validate_and_normalize(string) click to toggle source

# File lib/postkode.rb, line 83
def self.validate_and_normalize(string)
  return nil unless validate(string)
  validate(string, true).
    map(&:to_s).
    map(&:upcase).
    join(" ")
end