Change attributes of substrings in a NSAttributedString

Question

This question may be a duplicate of this one. But the answers don't work for me and I want to be more specific.

I have a NSString, but I need a NS(Mutable)AttributedString and some of the words in this string should be given a different color. I tried this:

NSString *text = @"This is the text and i want to replace something";

NSDictionary *attributes = @ {NSForegroundColorAttributeName : [UIColor redColor]};
NSMutableAttributedString *subString = [[NSMutableAttributedString alloc] initWithString:@"AND" attributes:attributes];

NSMutableAttributedString *newText = [[NSMutableAttributedString alloc] initWithString:text];

newText = [[newText mutableString] stringByReplacingOccurrencesOfString:@"and" withString:[subString mutableString]];

The "and" should be uppercase an red.

The documentation says that mutableString keeps the attribute mappings. But with my replacing-thing, I have no more attributedString on the right side of the assignment (in the last line of my code-snippet).

How can I get what I want? ;)

Answer 1

@Hyperlord's answer will work, but only if there is one occurence of the word "and" in the input string. Anyway, what I would do is use NSString's stringByReplacingOccurrencesOfString: initially to change every "and" to an "AND", then use a little regex to detect matches in attributed string, and apply NSForegroundColorAttributeName at that range. Here's an example:

NSString *initial = @"This is the text and i want to replace something and stuff and stuff";
NSString *text = [initial stringByReplacingOccurrencesOfString:@"and" withString:@"AND"];

NSMutableAttributedString *mutableAttributedString = [[NSMutableAttributedString alloc] initWithString:text];

NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(AND)" options:kNilOptions error:nil];


NSRange range = NSMakeRange(0,text.length);

[regex enumerateMatchesInString:text options:kNilOptions range:range usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {

    NSRange subStringRange = [result rangeAtIndex:1];
    [mutableAttributedString addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:subStringRange];
}];

And finally, just apply the attributed string to your label.

[myLabel setAttributedText:mutableAttributedString];