Make the specific string Pattern bold and blue in UILable - iphone

Question

i have a program in which i get a tweets from twitter and show them in UITableviewcell. now problem is that i have to make a all twitter names bold and bule and show them in the orginal tweet with bule and bold names.
For Example i have tweet like this
MT #OraTV: SNEAK PEEK: #tomgreenlive #TheoVon & #DavidBegnaud talk Miley's #twerking #Batfleck &more on
so all the names starting with # should be bold and bule.
i use this code to extract All names starting with # but not know how to bold them and show
them in single uitableviewcell
NSString * aString =twitterMessage
NSMutableArray *substrings = [NSMutableArray new];
NSScanner *scanner = [NSScanner scannerWithString:aString];
[scanner scanUpToString:#"#" intoString:nil];
while(![scanner isAtEnd]) {
NSString *substring = nil;
[scanner scanString:#"#" intoString:nil];
if([scanner scanUpToString:#" " intoString:&substring]) {
[substrings addObject:substring];
}
[scanner scanUpToString:#"#" intoString:nil];
}

Answer 1

you have to build an NSAttributedString by swiping between 2 fonts and colors.
If you're able to detect them, you should probably replace your names by surrounding them with a known markup (eg: #aName). Then, parse the string to build a NSAttributedString.
You can use this code (not tested, you'll probably have to tweak):
// String to parse
NSString *markup = #"MT <color>#OraTV</color>: SNEAK PEEK: <color>#tomgreenlive</color>...";
// Names font and color
UIFont *boldFont = [UIFont boldSystemFontOfSize:15.0f];
UIColor *boldColor = [UIColor blueColor];
// Other text font and color
UIFont *stdFont = [UIFont systemFontOfSize:15.0f];
UIColor *stdColor = [UIColor blackColor];
// Current font and color
UIFont *currentFont = stdFont;
UIColor *currentColor = stdColor;
// Parse HTML string
NSMutableAttributedString *aString = [[NSMutableAttributedString alloc] initWithString:#""];
NSRegularExpression *regex = [[NSRegularExpression alloc] initWithPattern:#"(.*?)(<[^>]+>|\\Z)"
options:NSRegularExpressionCaseInsensitive|NSRegularExpressionDotMatchesLineSeparators
error:nil];
NSArray *chunks = [regex matchesInString:markup options:0 range:NSMakeRange(0, [markup length])];
for (NSTextCheckingResult* b in chunks)
{
NSArray *parts = [[markup substringWithRange:b.range] componentsSeparatedByString:#"<"];
NSDictionary *attrs = [NSDictionary dictionaryWithObjectsAndKeys:currentFont,NSFontAttributeName,currentColor,NSForegroundColorAttributeName,nil];
[aString appendAttributedString:[[NSAttributedString alloc] initWithString:[parts objectAtIndex:0] attributes:attrs]];
if([parts count] > 1)
{
NSString *tag = (NSString *)[parts objectAtIndex:1];
if([tag hasPrefix:#"color"])
{
currentFont = boldFont;
currentColor = boldColor;
}
else if([tag hasPrefix:#"/color"])
{
currentFont = stdFont;
currentColor = stdColor;
}
}
}
Hope that helps.
Cyril

Answer 2

So you have all the names properly extracted already? If so, it seems like NSAttributedString is what you want. More information here.
Something like this: [str setTextColor:[UIColor blueColor] range:NSMakeRange(0,5)];
For bold text, use [UIFont boldSystemFontOfSize:fontSize]. See example in the second link above.