NSString find regular expression and replace it with image (NSMutableAttributeString)

Question

I know that something like this has already been asked but I found no solution for my issue.

So, I have a NSString, which sometimes includes in the text a image name, like:

Lorem ipsum....
image.png
... dolor sit elit lamet

I'd like to put in that space an image named 'image.png' in my NSMutableAttributedString.

This is my code to fetch matchings

NSString *regEx = @"([a-z])+(?:([0-9])+){0,1}.png";
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression
                              regularExpressionWithPattern:regEx
                              options:NSRegularExpressionCaseInsensitive error:&error];
if(error != nil){
    NSLog(@"Error: %@",error);
} else{
    [regex enumerateMatchesInString:myString options:0 range:NSMakeRange(0, [myString length]) usingBlock:^(NSTextCheckingResult *match, NSMatchingFlags flags, BOOL *stop){
        // your code to handle matches here

        NSLog(@"found!");
    }];
}

How can I add an image in a NSMutableAttributedString, calling imageNamed function for each found sub-string?

Answer 1

Apparently I resolved it. Inside the for there is the code to replace a substring with an image in the NSMutableAttributedString. Also I decided to put a reversed for in inspiration to a previous answer in a question similar (but different) like this

NSMutableAttributedString *formattedText = myString.mutableAttributedString;

// Look for image
NSString *regEx = @"([a-z])+(?:([0-9])+){0,1}.png";
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression
                              regularExpressionWithPattern:regEx
                              options:NSRegularExpressionCaseInsensitive error:&error];
if(error != nil){
    NSLog(@"Error: %@",error);
} else{
    NSArray *matches = [regex matchesInString:myString
                                      options:kNilOptions
                                        range:NSMakeRange(0, myString.length)];
    for (NSTextCheckingResult *result in [matches reverseObjectEnumerator])
    {
        NSString *insideString = [myString substringWithRange:[result rangeAtIndex:0]];
        UIImage *image = [UIImage imageNamed:insideString];
        NSTextAttachment *imageAttachment = [NSTextAttachment new];
        imageAttachment.image = image;
        NSAttributedString *replacementForTemplate = [NSAttributedString attributedStringWithAttachment:imageAttachment];
        [formattedText replaceCharactersInRange:result.range
                           withAttributedString:replacementForTemplate];

        NSLog(@"found! -> %@", insideString);

    }
}

Instead the mutableAttributedString property belongs to a NSString Category. This is the code of it

- (NSMutableAttributedString *)mutableAttributedString {
    return [[NSMutableAttributedString alloc] initWithString:self];
}