NSString check if the string contains composed characters.

NSString

+ (BOOL)stringContainsComposedCharacters:(NSString *)string
{
    __block BOOL contains = NO;
    [string enumerateSubstringsInRange:NSMakeRange(0, string.length)
                               options:NSStringEnumerationByComposedCharacterSequences
                            usingBlock:
     ^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop)
    {
        if (substringRange.length > 1)
        {
            contains = YES;
            *stop = YES;
        }
     }];
    
    return contains;
}