About AttributeString - making multiple occurrences bold - iphone

Question

I am trying to make multiple occurrences in a attributed string bold using something like the following
[attrStr setFont:[UIFont ...] range:[attrStr.string rangeOfString:#"hello world"]];
As you know, 'rangeOfString' always return the FIRST occurrence of the match... I am still quite new to iOS, just wondering what's the best way to set all occurrences to bold... Is there any function provided in NSString or something?
Thanks in advance!

Answer 1

You should first try to get all ranges in the string and then set the attribute for every range. There are some great code examples right here on stackoverflow: https://stackoverflow.com/a/4653266/381870
Edit:
Here's an example for you
- (NSArray *)rangesOfString:(NSString *)searchString inString:(NSString *)str {
NSMutableArray *results = [NSMutableArray array];
NSRange searchRange = NSMakeRange(0, [str length]);
NSRange range;
while ((range = [str rangeOfString:searchString options:0 range:searchRange]).location != NSNotFound) {
[results addObject:[NSValue valueWithRange:range]];
searchRange = NSMakeRange(NSMaxRange(range), [str length] - NSMaxRange(range));
}
return results;
}
Usage:
NSArray *results = [self rangesOfString:#"foo" inString:#"foo bar foo"];
NSLog(#"%#", results);
gives you
(
"NSRange: {0, 3}",
"NSRange: {8, 3}"
)

Answer 2

Converting Tim's answer to Swift 4:
extension NSString {
open func ranges(of searchString: String) -> [NSRange] {
var ranges = [NSRange]()
var searchRange = NSRange(location: 0, length: self.length)
var range: NSRange = self.range(of: searchString)
while range.location != NSNotFound {
ranges.append(range)
searchRange = NSRange(location: NSMaxRange(range), length: self.length - NSMaxRange(range))
range = self.range(of: searchString, options: [], range: searchRange)
}
return ranges
}
}
Also did it to Swift's String primitive:
extension String {
func ranges(of substring: String, options: CompareOptions = [], locale: Locale? = nil) -> [Range<Index>] {
var ranges: [Range<Index>] = []
while let range = self.range(of: substring, options: options, range: (ranges.last?.upperBound ?? self.startIndex)..<self.endIndex, locale: locale) {
ranges.append(range)
}
return ranges
}
}

Answer 3

You will like have to use NSScanner to scan through the text and replace it.You can find an example for NSScanner here.