Objective-C

Unicode Escape and Unescape Text in StringBuilder

Demonstrates options for unicode escaping non-us-ascii chars and emojis. Objective-C

#import <CkoStringBuilder.h>
#import <NSString.h>

BOOL success = NO;

CkoStringBuilder *sbOriginal = [[CkoStringBuilder alloc] init];
success = [sbOriginal LoadFile: @"qa_data/txt/utf16_emojis_accented_jap.txt" charset: @"utf-16"];
if (success == NO) {
    NSLog(@"%@",sbOriginal.LastErrorText);
    return;
}

//  The above file contains the following text, which includes some emoji's,
//  Japanese chars, and accented chars.

CkoStringBuilder *sb = [[CkoStringBuilder alloc] init];
[sb AppendSb: sbOriginal];

//  Charset is not used for unicode escaping.  Set it to "utf-8", but it means nothing.
NSString *charsetNotUsed = @"utf-8";

//  Indicate the desired format/style of Unicode escaping.
//  Choose JSON-style (JavaScript-style) Unicode escape sequences by using "unicodeescape"
NSString *encoding = @"unicodeescape";

[sb Encode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  Output:
//  \ud83e\udde0
//  \ud83d\udd10
//  \u2705
//  \u26a0\ufe0f
//  \u274c
//  \u2713
//  \u4e2d
//  \u00e9 xyz \u00e0
//  abc \u79c1 \u306f \u3093 ghi

//  Revert back to the unescaped chars:
[sb Decode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  -----------------------------------------------------------------------------------------
//  Do the same, but use uppercase letters (A-F) in the hex values.
encoding = @"unicodeescape-upper";
[sb Encode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  Output:
//  \uD83E\uDDE0
//  \uD83D\uDD10
//  \u2705
//  \u26A0\uFE0F
//  \u274C
//  \u2713
//  \u4E2D
//  \u00E9 xyz \u00E0
//  abc \u79C1 \u306F \u3093 ghi

//  Revert back to the unescaped chars:
[sb Decode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  -----------------------------------------------------------------------------------------
//   ECMAScript (JavaScript) �code point escape� syntax

encoding = @"unicodeescape-curly";
[sb Encode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  Output:
//  \u{d83e}\u{dde0}
//  \u{d83d}\u{dd10}
//  \u{2705}
//  \u{26a0}\u{fe0f}
//  \u{274c}
//  \u{2713}
//  \u{4e2d}
//  \u{00e9} xyz \u{00e0}
//  abc \u{79c1} \u{306f} \u{3093} ghi

//  Revert back to the unescaped chars:
[sb Decode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  -----------------------------------------------------------------------------------------
//  Do the same, but use uppercase letters (A-F) in the hex values.
encoding = @"unicodeescape-curly-upper";
[sb Encode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  Output:
//  \u{D83E}\u{DDE0}
//  \u{D83D}\u{DD10}
//  \u{2705}
//  \u{26A0}\u{FE0F}
//  \u{274C}
//  \u{2713}
//  \u{4E2D}
//  \u{00E9} xyz \u{00E0}
//  abc \u{79C1} \u{306F} \u{3093} ghi

//  Revert back to the unescaped chars:
[sb Decode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  -----------------------------------------------------------------------------------------
//  HTML hexadecimal character reference

encoding = @"unicodeescape-htmlhex";
[sb Encode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  Output:
//  &#x1f9e0;
//  &#x1f510;
//  &#x2705;
//  &#x26a0;&#xfe0f;
//  &#x274c;
//  &#x2713;
//  &#x4e2d;
//  &#xe9; xyz &#xe0;
//  abc &#x79c1; &#x306f; &#x3093; ghi

//  Revert back to the unescaped chars:
[sb Decode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  -----------------------------------------------------------------------------------------
//  HTML decimal character reference

encoding = @"unicodeescape-htmldec";
[sb Encode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  Output:
//  &#129504;
//  &#128272;
//  &#9989;
//  &#9888;&#65039;
//  &#10060;
//  &#10003;
//  &#20013;
//  &#233; xyz &#224;
//  abc &#31169; &#12399; &#12435; ghi

//  Revert back to the unescaped chars:
[sb Decode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  -----------------------------------------------------------------------------------------
//  Unicode code point notation or U+ notation

encoding = @"unicodeescape-plus";
[sb Encode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  Output:
//  u+1f9e0
//  u+1f510
//  u+2705
//  u+26a0u+fe0f
//  u+274c
//  u+2713
//  u+4e2d
//  u+00e9 xyz u+00e0
//  abc u+79c1 u+306f u+3093 ghi

//  Chilkat cannot unescape the Unicode code point notation or U+ notation.
//  For this style, Chilkat only goes in one direction, which is to escape.

//  To emit uppercase hex, specify unicodeescape-plus-upper
encoding = @"unicodeescape-plus-upper";
//  ...
//  ...

[sb Clear];
[sb AppendSb: sbOriginal];

//  -----------------------------------------------------------------------------------------
//  Hex in Angle Brackets

encoding = @"unicodeescape-angle";
[sb Encode: encoding charset: charsetNotUsed];
NSLog(@"%@",[sb GetAsString]);

//  Output:
//  <1f9e0>
//  <1f510>
//  <2705>
//  <26a0><fe0f>
//  <274c>
//  <2713>
//  <4e2d>
//  <e9> xyz <e0>
//  abc <79c1> <306f> <3093> ghi

//  Chilkat cannot unescape the angle bracket notation.
//  For this style, Chilkat only goes in one direction, which is to escape.

[sb Clear];
[sb AppendSb: sbOriginal];