I'm currently teaching myself NSRegularExpressions and how to filter certain things out of RSS feeds. Particularly, the RSS feed is in the format "some text :: (there can be a Re: here for a reply) some text :: some text". I would like to remove that Re: if it exists. I know that there should be a way to do this without creating another NSRegularExpression within the one I currently have. I don't have a grasp on all of the symbols. I was trying to use ?: to uninclude the Re: from capture, but I can't quite figure out how. Would someone mind looking at this for me and giving me a helping hand?
NSRegularExpression *reg = [[NSRegularExpression alloc] initWithPattern:@".* :: ?:Re: (.*) :: .*" options:0 error:nil]; //The () creates a capture group and an array of ranges for reg
//Loop through every title of the items in channel
for (RSSItem *i in items) {
NSString *itemTitle = [i title];
//find mittts
//Find matches in the title string. The range argument specifies how much of the title to search; in this case, all of it.
NSArray *matches = [reg matchesInString:itemTitle options:0 range:NSMakeRange(0, [itemTitle length])];
//If there was a match...
if ([matches count] > 0) {
//Print the location of the match in the string and the string
NSTextCheckingResult *result = [matches objectAtIndex:0];
NSRange r = [result range];
NSLog(@"\nMatch at {%d, %d} for %@!\n", r.location, r.length, itemTitle);
NSLog(@"Range : %d",[result numberOfRanges]);
//One capture group, so two ranges, let's verify
if ([result numberOfRanges] == 2) {
//Pull out the 2nd range, which will be the capture group
NSRange r = [result rangeAtIndex:1];
//Set the title of the item to the string within the capture group
[i setTitle:[itemTitle substringWithRange:r]];
NSLog(@"%@", [itemTitle substringWithRange:r]);
}
}
}
Never mind, found it. I needed (?:Re: )? to prevent capturing it.