nspredicate to find lines containing markdown reference links

cocoaPredicateMkDn

- (NSArray *)referenceLinksInString:(NSString *)contentString{    
    NSString *wildString = @"*[*]:*http*"; //This is where you define your match string.    
    NSPredicate *matchPred = [NSPredicate predicateWithFormat:@"SELF LIKE[cd] %@", wildString]; 
    /*
     Breaking it down:
     SELF is the string you're testing
     [cd] makes the test case-insensitive
     LIKE is one of the predicate search possiblities. It's NOT regex, but lets you use wildcards '?' for one character and '*' for any number of characters
     MATCH (not used) is what you would use for Regex. And you'd set it up similiar to LIKE. I don't really know regex, and I can't quite get it to work. But that might be because I don't know regex. 
     %@ you need to pass in the search string like this, rather than just embedding it in the format string. so DON'T USE something like [NSPredicate predicateWithFormat:@"SELF LIKE[cd] *[*]:*http*"]
     */
    
    NSMutableArray *referenceLinks=[NSMutableArray new];
    
    //enumerateLinesUsing block seems like a good way to go line by line thru the note and test each line for the regex match of a reference link. Downside is that it uses blocks so requires 10.6+. Let's get it to work and then we can figure out a Leopard friendly way of doing this; which I don't think will be a problem (famous last words).
    [contentString enumerateLinesUsingBlock:^(NSString *line, BOOL *stop) { 
        if([matchPred evaluateWithObject:line]){
            //            NSLog(@"%@ matched",line);
            NSString *theRef=line;
            //theRef=[line substring...]  here you want to parse out and get just the name of the reference link we'd want to offer up to the user in the autocomplete
            //and maybe trim out whitespace
            theRef = [theRef stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
            //check to make sure its not empty
            if(![theRef isEqualToString:@""]){
                [referenceLinks addObject:theRef];
            } 		
        }	
    }];
    //create an immutable array safe for returning
    NSArray *returnArray=[NSArray array];
    //see if we found anything
    if(referenceLinks&&([referenceLinks count]>0))
    {
        returnArray=[NSArray arrayWithArray:referenceLinks];
    }
    [referenceLinks release];
    return returnArray;
}