Change attributes of substrings in a NSAttributedString - ios

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];

Answer 2

I think you should create a NSMutableAttributedString using the existing NSString and then add the style attributes with the appropriate NSRange in order to colorize the parts you want to emphasize for example:
NSString *text = #"This is the text and i want to replace something";
NSMutableAttributedString *mutable = [[NSMutableAttributedString alloc] initWithString:text];
[mutable addAttribute: NSForegroundColorAttributeName value:[UIColor redColor] range:[text rangeOfString:#"and"]];
Be aware: this is just from my head and not tested at all ;-)

Answer 3

Please try this code in Swift 2
var someStr = "This is the text and i want to replace something"
someStr.replaceRange(someStr.rangeOfString("and")!, with: "AND")
let attributeStr = NSMutableAttributedString(string: someStr)
attributeStr.setAttributes([NSForegroundColorAttributeName: UIColor.yellowColor()], range: NSMakeRange(17, 3) )
testLbl.attributedText = attributeStr

Answer 4

Here's another implementation (in Swift) that's helpful if you're doing some more complex manipulations (such as adding/deleting characters) with your attributed string:
let text = "This is the text and i want to replace something"
let mutAttrStr = NSMutableAttributedString(string: text)
let pattern = "\\band\\b"
let regex = NSRegularExpression(pattern: pattern, options: .allZeros, error: nil)
while let result = regex!.firstMatchInString(mutAttrStr.string, options: .allZeros, range:NSMakeRange(0, count(mutAttrStr.string)) {
let substring = NSMutableAttributedString(attributedString: mutAttrStr.attributedSubstringFromRange(result.range))
// manipulate substring attributes here
substring.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor(), range NSMakeRange(0, count(substring.string))
mutAttrStr.replaceCharactersInRange(result.range, withAttributedString: substring)
}
Your final attributed string should be:
let finalAttrStr = mutAttrStr.copy() as! NSAttributedString