Swift

Convert utf-8 Text File to Windows-1252

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

func chilkatTest() {
    var success: Bool = false

    // 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.

    let bd = CkoBinData()!

    // Load the utf-8 bytes.
    success = bd.loadFile(path: "qa_data/xml/utf8test.xml")
    if success == false {
        print("\(bd.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.
    var allOrNone: Bool = false
    var fromCharset: String? = "utf-8"
    var toCharset: String? = "windows-1252"
    success = bd.charsetConvert(fromCharset: fromCharset, toCharset: toCharset, allOrNone: allOrNone)

    // The return value will be false if any utf-8 chars were discarded because of non-convertability.
    if success == false {
        print("Some utf-8 chars could not be converted to windows-1252")
    }
    else {
        print("All utf-8 chars were converted to windows-1252")
    }

    success = bd.writeFile(path: "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>

}