Dart

Demonstrate the Global.AutoQBDecode property

The Global.AutoQBDecode property can be set to _TRUE_ to cause Q/B encoded string arguments passed to any Chilkat method to be automatically decoded before being used.

Note: This example requires Chilkat v10.0.0 or later.

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Turn on auto Q/B decoding for all strings passed to any Chilkat method in any Chilkat class.
  final glob = CkGlobal();
  glob.autoQBDecode = true;

  // ---------------------------------------------------------------------------------------------------------------------------------------------
  // "Q" Encoding

  // Quoted-Printable encoding is primarily used for text that is mostly ASCII with some non-ASCII characters. 
  // It encodes these characters in a way that remains mostly readable and compatible with ASCII-only systems.

  // How It Works with UTF-8:
  // - ASCII characters (except special characters like `=`) are encoded as themselves.
  // - Non-ASCII characters are represented by their UTF-8 byte values, each byte encoded as `=` followed by two hexadecimal digits. 
  //   For example, the UTF-8 character "é" (U+00E9) is encoded as `=C3=A9`.

  // For example, consider the text "Café" encoded in UTF-8. The UTF-8 bytes for "é" are `C3 A9`, so in Quoted-Printable, it looks like this:  Caf=C3=A9

  // The "Q" encoding has this syntax:  "=?charset?q?encoded_text?="
  // For example: "=?UTF-8?Q?Caf=C3=A9_announcement?="

  // ------
  // "B" Encoding

  // Base64 encoding is used to encode non-ASCII text, making it more suitable for text with a high density of non-ASCII characters, such as those found in non-Western European languages.

  // For example, consider the text "こんにちは" ("Hello" in Japanese).
  // The "B" encoded string would be "=?UTF-8?B?44GT44KT44Gr44Gh44Gv?="

  // ------
  // Q encoding is suitable for text that is mostly ASCII.
  // B Encoding is best for text that is densely packed with non-us-ascii chars, such as non-Latin (Asian) languages.
  // ---------------------------------------------------------------------------------------------------------------------------------------------

  // You can use Chilkat's online tool at Online Binary Encoder to pre-encode your literal strings before
  // inserting them into your source code.

  // When using the online tool, choose either "MIME header Q Encoding" or "MIME Header B Encoding".

  // For example:
  final sCafe = '=?utf-8?Q?Caf=C3=A9?=';
  final s1 = CkStringBuilder();
  s1.append(sCafe);
  print(s1.getAsString());
  // Output is Café

  final sHello = '=?UTF-8?B?44GT44KT44Gr44Gh44Gv?=';
  final s2 = CkStringBuilder();
  s2.append(sHello);
  print(s2.getAsString());
  // Output is こんにちは
}