CODEWITHSUNDEEP
ruby-on-railsruby
g_es
g_es

Reputation: 95

Country code validation with ISO

I have in my model country code field. How can I validate if it is correct with ISO standards ?

Upvotes: 3

Views: 10119

Answers (3)

Eric Duminil
Eric Duminil

Reputation: 54243

CountryCode validation

# Does code belong to the 249 ones defined in
#   "ISO 3166-1 alpha-2" or
#   "ISO 3166-1 alpha-3" ?
class CountryCode
  ISO_3166_ALPHA_2 = /^A[^ABCHJKNPVY]|B[^CKPUX]|C
  [^BEJPQST]|D[EJKMOZ]|E[CEGHRST]|F[IJKMOR]|G[^CJ
  KOVXZ]|H[KMNRTU]|I[DEL-OQ-T]|J[EMOP]|K[EGHIMNPR
  WYZ]|L[ABCIKR-VY]|M[^BIJ]|N[ACEFGILOPRUZ]|OM|P[
  AE-HK-NRSTWY]|QA|R[EOSUW]|S[^FPQUW]|T[^ABEIPQSU
  XY]|U[AGMSYZ]|V[ACEGINU]|WF|WS|YE|YT|Z[AMW]$/ix

  ISO_3166_ALPHA_3 = /^A(BW|FG|GO|IA|L[AB]|ND|R[EGM]|SM|T[A
  FG]|U[ST]|ZE)|B(DI|E[LNS]|FA|G[DR]|H[RS]|IH|L[MRZ]|MU|OL|
  R[ABN]|TN|VT|WA)|C(A[FN]|CK|H[ELN]|IV|MR|O[DGKLM]|PV|RI|U
  [BW]|XR|Y[MP]|ZE)|D(EU|JI|MA|NK|OM|ZA)|E(CU|GY|RI|S[HPT]|
  TH)|F(IN|JI|LK|R[AO]|SM)|G(AB|BR|EO|GY|HA|I[BN]|LP|MB|N[B
  Q]|R[CDL]|TM|U[FMY])|H(KG|MD|ND|RV|TI|UN)|I(DN|MN|ND|OT|R
  [LNQ]|S[LR]|TA)|J(AM|EY|OR|PN)|K(AZ|EN|GZ|HM|IR|NA|OR|WT)
  |L(AO|B[NRY]|CA|IE|KA|SO|TU|UX|VA)|M(A[CFR]|CO|D[AGV]|EX|
  HL|KD|L[IT]|MR|N[EGP]|OZ|RT|SR|TQ|US|WI|Y[ST])|N(AM|CL|ER
  |FK|GA|I[CU]|LD|OR|PL|RU|ZL)|OMN|P(A[KN]|CN|ER|HL|LW|NG|O
  L|R[IKTY]|SE|YF)|QAT|R(EU|OU|US|WA)|S(AU|DN|EN|G[PS]|HN|J
  M|L[BEV]|MR|OM|PM|RB|SD|TP|UR|V[KN]|W[EZ]|XM|Y[CR])|T(C[A
  D]|GO|HA|JK|K[LM]|LS|ON|TO|U[NRV]|WN|ZA)|U(GA|KR|MI|RY|SA
  |ZB)|V(AT|CT|EN|GB|IR|NM|UT)|W(LF|SM)|YEM|Z(AF|MB|WE)$/ix

  def self.valid_iso_alpha2?(code)
    !(code =~ /\A[A-Z]{2}\Z/i && code =~ ISO_3166_ALPHA_2).nil?
  end

  def self.valid_iso_alpha3?(code)
    !(code =~ /\A[A-Z]{3}\Z/i && code =~ ISO_3166_ALPHA_3).nil?
  end

  def self.valid_iso?(code)
    valid_iso_alpha2?(code) || valid_iso_alpha3?(code)
  end
end

CountryCode.valid_iso?('Fra')       #=> true
CountryCode.valid_iso?('USA')       #=> true
CountryCode.valid_iso_alpha3?('US') #=> false
CountryCode.valid_iso?('USX')       #=> false

Explanation

Regex for ISO 3166-1 alpha-2

Just for fun, I tried to find a shortish Regex to validate Alpha-2 ISO code :

# wget http://data.okfn.org/data/core/country-list/r/data.json

require 'json'

codes = JSON.parse(File.read('data.json')).map { |country| country['Code'] }.sort

regex = codes.group_by { |code| code[0] }.map do |first_letter, codes|
  second_letters = codes.map { |code| code[1] }
  regex_1 = codes.join('|')
  regex_2 = first_letter + '[' + second_letters.join + ']'
  regex_3 = first_letter + '[^' + (('A'..'Z').to_a - second_letters).join + ']'

  [regex_1, regex_2, regex_3].min_by(&:size)
end.join('|')

regex = Regexp.new('^' + regex + '$')

p regex
# => /^A[^ABCHJKNPVY]|B[^CKPUX]|C[^BEJPQST]|D[EJKMOZ]|E[CEGHRST]|F[IJKMOR]|G[^CJKOVXZ]|H[KMNRTU]|I[DELMNOQRST]|J[EMOP]|K[EGHIMNPRWYZ]|L[ABCIKRSTUVY]|M[^BIJ]|N[ACEFGILOPRUZ]|OM|P[^BCDIJOPQUVXZ]|QA|R[EOSUW]|S[^FPQUW]|T[^ABEIPQSUXY]|U[AGMSYZ]|V[ACEGINU]|WF|WS|YE|YT|Z[AMW]$/
p ('AA'..'ZZ').select { |two_letters| two_letters =~ regex } == codes
#=> true

The script groups all the codes by first letter, and looks for the shortest way to list the second letters.

So for 2-letter country code, you can validate with :

iso_3166_alpha_2 = /^A[^ABCHJKNPVY]|B[^CKPUX]|C
[^BEJPQST]|D[EJKMOZ]|E[CEGHRST]|F[IJKMOR]|G[^CJ
KOVXZ]|H[KMNRTU]|I[DEL-OQ-T]|J[EMOP]|K[EGHIMNPR
WYZ]|L[ABCIKR-VY]|M[^BIJ]|N[ACEFGILOPRUZ]|OM|P[
AE-HK-NRSTWY]|QA|R[EOSUW]|S[^FPQUW]|T[^ABEIPQSU
XY]|U[AGMSYZ]|V[ACEGINU]|WF|WS|YE|YT|Z[AMW]$/ix

NOTE: You should first check that the code is with letters only. "B%" matches otherwise.

Regex for ISO 3166-1 alpha-3

There's obviously less repetition for 3 letter codes, so the regex is harder to compress. I used a Trie to get this regex :

iso_3166_alpha_3 = /^A(BW|FG|GO|IA|L[AB]|ND|R[EGM]|SM|T[A
FG]|U[ST]|ZE)|B(DI|E[LNS]|FA|G[DR]|H[RS]|IH|L[MRZ]|MU|OL|
R[ABN]|TN|VT|WA)|C(A[FN]|CK|H[ELN]|IV|MR|O[DGKLM]|PV|RI|U
[BW]|XR|Y[MP]|ZE)|D(EU|JI|MA|NK|OM|ZA)|E(CU|GY|RI|S[HPT]|
TH)|F(IN|JI|LK|R[AO]|SM)|G(AB|BR|EO|GY|HA|I[BN]|LP|MB|N[B
Q]|R[CDL]|TM|U[FMY])|H(KG|MD|ND|RV|TI|UN)|I(DN|MN|ND|OT|R
[LNQ]|S[LR]|TA)|J(AM|EY|OR|PN)|K(AZ|EN|GZ|HM|IR|NA|OR|WT)
|L(AO|B[NRY]|CA|IE|KA|SO|TU|UX|VA)|M(A[CFR]|CO|D[AGV]|EX|
HL|KD|L[IT]|MR|N[EGP]|OZ|RT|SR|TQ|US|WI|Y[ST])|N(AM|CL|ER
|FK|GA|I[CU]|LD|OR|PL|RU|ZL)|OMN|P(A[KN]|CN|ER|HL|LW|NG|O
L|R[IKTY]|SE|YF)|QAT|R(EU|OU|US|WA)|S(AU|DN|EN|G[PS]|HN|J
M|L[BEV]|MR|OM|PM|RB|SD|TP|UR|V[KN]|W[EZ]|XM|Y[CR])|T(C[A
D]|GO|HA|JK|K[LM]|LS|ON|TO|U[NRV]|WN|ZA)|U(GA|KR|MI|RY|SA
|ZB)|V(AT|CT|EN|GB|IR|NM|UT)|W(LF|SM)|YEM|Z(AF|MB|WE)$/ix

Upvotes: 7

JackBites
JackBites

Reputation: 146

I made you a gem, https://github.com/jackbit/validiso, please let me know if i am correct. Thanks.

Usage

Search by code

Validiso::Countries.find_code('971')

Search by alpha2

Validiso::Countries.find_alpha2('AE')

Search by alpha3:

Validiso::Countries.find_alpha3('ARE')

It will return nil if not exist, but if success it will return the following object

{
    "country_code": "971",
    "alpha2": "AE",
    "alpha3": "ARE",
    "name": "United Arab Emirates",
    "continent": "Asia"
}

Upvotes: 1

Mahabub Islam Prio
Mahabub Islam Prio

Reputation: 1085

Hi you always can use this GEM Gem Github Link... hope this will solve your problem .

Upvotes: 1

Related Questions