Detect if string contains emoji (Using Objective-C and Swift)

ContainsEmoji.m

#import <UIKit/UIKit.h>
#import <CoreFoundation/CoreFoundation.h>
#import <CoreGraphics/CoreGraphics.h>
#import <CoreText/CoreText.h>

@interface EmojiUtilities : NSObject
+ (CFMutableCharacterSetRef)emojiCharacterSet;
+ (BOOL)containsEmoji:(NSString *)emoji;
@end

@implementation EmojiUtilities

+ (CFMutableCharacterSetRef)emojiCharacterSet {
    static CFMutableCharacterSetRef set = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        set = CFCharacterSetCreateMutableCopy(kCFAllocatorDefault, CTFontCopyCharacterSet(CTFontCreateWithName(CFSTR("AppleColorEmoji"), 0.0, NULL)));
        CFCharacterSetRemoveCharactersInString(set, CFSTR(" 0123456789#*"));
    });
    return set;
}

+ (BOOL)containsEmoji:(NSString *)emoji {
    return CFStringFindCharacterFromSet((CFStringRef)emoji, [self emojiCharacterSet], CFRangeMake(0, emoji.length), 0, NULL);
}

@end

ContainsEmoji.swift

import UIKit
import CoreFoundation
import CoreGraphics
import CoreText

class EmojiUtilities {
    
    static var emojiCharacterSet = EmojiUtilities.getCharacterSet()
    
    class func getCharacterSet() -> CFMutableCharacterSet? {
        let nullPtr: UnsafePointer<CGAffineTransform>? = nil
        let set = CFCharacterSetCreateMutableCopy(kCFAllocatorDefault, CTFontCopyCharacterSet(CTFontCreateWithName("AppleColorEmoji" as CFString, 0.0, nullPtr)))
        CFCharacterSetRemoveCharactersInString(set, " 0123456789#*" as CFString);
        return set
    }

    class func containsEmoji(emoji: String) -> Bool {
        let nullPtr: UnsafeMutablePointer<CFRange>? = nil
        return CFStringFindCharacterFromSet(emoji as CFString, emojiCharacterSet, CFRangeMake(0, CFStringGetLength(emoji as CFString)), CFStringCompareFlags(rawValue: 0), nullPtr);
    }
    
}

// Testing
EmojiUtilities.containsEmoji(emoji: "Hi 👩‍🌾")
EmojiUtilities.containsEmoji(emoji: "👩🏻‍💻")

Elegant. But, seems to identify a space as an emoji.

CFCharacterSetRef emojiSetWithSpace = CTFontCopyCharacterSet(CTFontCreateWithName(CFSTR("AppleColorEmoji"), 0.0, NULL));
CFMutableCharacterSetRef emojiCharacterSet = CFCharacterSetCreateMutableCopy(NULL, emojiSetWithSpace); CFCharacterSetRemoveCharactersInString(emojiCharacterSet, (CFStringRef)@" "); // And whatever other characters you don't want to identified as emoji

Elegant. But, seems to identify a space as an emoji.

CFCharacterSetRef emojiSetWithSpace = CTFontCopyCharacterSet(CTFontCreateWithName(CFSTR("AppleColorEmoji"), 0.0, NULL));
CFMutableCharacterSetRef emojiCharacterSet = CFCharacterSetCreateMutableCopy(NULL, emojiSetWithSpace); CFCharacterSetRemoveCharactersInString(emojiCharacterSet, (CFStringRef)@" "); // And whatever other characters you don't want to identified as emoji

If you hadn’t written, I wouldn’t have noticed, thanks!
Best to add more characters:
CFCharacterSetRemoveCharactersInString(emojiCharacterSet, (CFStringRef)@" 0123456789#*");