Dart Requires Chilkat v11.0.0+

Convert utf-8 Text File to Windows-1252

Demonstrates how to convert a text file using the utf-8 byte representation to windows-1252. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Converts a file containing the following to windows-1252:

  // <greetings>
  //     <message>Hello, world!</message>
  //     <message>¡Hola, mundo!</message>
  //     <message>Bonjour, le monde!</message>
  //     <message>Hallo, Welt!</message>
  //     <message>Olá, mundo!</message>
  //     <message>Привет, мир!</message>
  //     <message>你好，世界！</message>
  //     <message>こんにちは、世界！</message>
  //     <message>안녕하세요, 세계!</message>
  //     <message>😊🌍</message>
  // </greetings>

  // --------------------------------------------------------------------------------------------------------------------------
  // Note:
  // Windows-1252 is an 8-bit single-byte encoding. It can only encode:
  // 
  //     The basic ASCII set (0x00–0x7F).
  //     Latin-1 Supplement (0xA0–0xFF), plus some extra printable characters (like curly quotes, €, etc.).
  //     In total: 256 possible code points, covering most Western European languages but nothing outside of Latin script.

  // --------------------------------------------------------------------------------------------------------------------------
  // Characters in your XML that are representable
  // 
  //     Hello, world! ✅ (ASCII only)
  //     ¡Hola, mundo! ✅ (inverted exclamation mark U+00A1 is in Windows-1252)
  //     Bonjour, le monde! ✅
  //     Hallo, Welt! ✅
  //     Olá, mundo! ✅ (U+00E1 á and U+00F3 ó are in Windows-1252)

  // --------------------------------------------------------------------------------------------------------------------------
  // Characters that break conversion
  // 
  //     Russian / Cyrillic: Привет, мир!
  //     → These are Cyrillic characters (U+041F … U+0440). Not representable in Windows-1252. Conversion would require replacement (e.g. with ? or XML character references).
  //     Chinese: 你好，世界！
  //     → CJK ideographs (U+4F60, U+597D, etc.). Not in Windows-1252.
  //     Japanese: こんにちは、世界！
  //     → Hiragana + CJK. Not in Windows-1252.
  //     Korean: 안녕하세요, 세계!
  //     → Hangul syllables. Not in Windows-1252.
  //     Emoji: 😊🌍
  //     → Unicode Supplementary Multilingual Plane (U+1F60A, U+1F30D). Windows-1252 cannot encode any emoji.

  final bd = CkBinData();

  // Load the utf-8 bytes.
  try {
    bd.loadFile('qa_data/xml/utf8test.xml');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // If allOrNone = true, then the conversion fails and the contents of the BinData
  // are left unchanged if any char is unconvertable.

  // If allOrNone = false, then non-convertable chars are discarded.
  final allOrNone = false;
  final fromCharset = 'utf-8';
  final toCharset = 'windows-1252';

  // The return value will be false if any utf-8 chars were discarded because of non-convertability.
  try {
    bd.charsetConvert(fromCharset, toCharset, allOrNone);
    print('All utf-8 chars were converted to windows-1252');
  } on ChilkatException {
    print('Some utf-8 chars could not be converted to windows-1252');
  }

  bd.writeFile('c:/temp/qa_output/out.xml');

  // The output file contains the following, where all non-convertable chars were discarded

  // <greetings>
  //     <message>Hello, world!</message>
  //     <message>¡Hola, mundo!</message>
  //     <message>Bonjour, le monde!</message>
  //     <message>Hallo, Welt!</message>
  //     <message>Olá, mundo!</message>
  //     <message>, !</message>
  //     <message></message>
  //     <message></message>
  //     <message>, !</message>
  //     <message></message>
  // </greetings>
}