Update BLZ2 20241209

bin/build_german_iban_rules.rb

@@ -1,42 +1,44 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
+# Script for parsing the Bankleitzahl file (BLZ2.xml) from the Deutsche Bundesbank.
+require "yaml"
+require "sax-machine"
+
+class BLZRecord
+  include SAXMachine
+  element "BLZ", as: :bank_code
+  element "Merkmal", as: :primary_record
+  element "PruefZiffMeth", as: :check_digit_rule
+  element "IBANRegel", as: :iban_rule
+end
 
-# Script for parsing the Bankleitzahl file (BLZ2.txt) from the Deutsche
-# Bundesbank.
-require 'yaml'
-
-BLZ_FIELDS = {
-  bank_code:           { position: 0, length: 8 },
-  primary_record:      { position: 8, length: 1 },
-  check_digit_rule:    { position: 150, length: 2 },
-  iban_rule:           { position: 168, length: 6 }
-}.freeze
-
-def parse_line(line)
-  BLZ_FIELDS.each_with_object({}) do |(field, details), hash|
-    hash[field] = line.slice(details[:position], details[:length])
-  end
+class BLZFile
+  include SAXMachine
+  elements "BLZEintrag", as: :records, class: BLZRecord
 end
 
 def get_iban_rules(blz2_file)
-  blz2_file.each_with_object({}) do |line, hash|
-    bank_details = parse_line(line)
-
-    next if bank_details.delete(:primary_record) == '2'
+  BLZFile.parse(blz2_file).records.each_with_object({}) do |bank_details, hash|
+    next if bank_details.primary_record == "2"
 
-    hash[bank_details.delete(:bank_code)] = bank_details
+    hash[bank_details.bank_code] = {
+      check_digit_rule: bank_details.check_digit_rule,
+      iban_rule: bank_details.iban_rule,
+    }
   end
 end
 
 # Only parse the files if this file is run as an executable (not required in,
 # as it is in the specs)
 if __FILE__ == $PROGRAM_NAME
-  blz2_file = File.open(File.expand_path('../../data/raw/BLZ2.txt', __FILE__))
+  blz2_file = File.read(File.expand_path("../data/raw/BLZ2.xml", __dir__))
   iban_rules = get_iban_rules(blz2_file)
 
   output_file_path = File.expand_path(
-    '../../data/german_iban_rules.yml',
-    __FILE__
+    "../data/german_iban_rules.yml",
+    __dir__,
   )
 
-  File.open(output_file_path, 'w') { |f| f.write(iban_rules.to_yaml) }
+  File.open(output_file_path, "w") { |f| f.write(iban_rules.to_yaml) }
 end