Detect a tap on a URL inside a UITextView.Note: the rs_links method isn't included -- you'll need something that takes text and returns an array of detected links. This gist just demonstrates walking through the UITextView characters.

gistfile1.m

#import "UITextView+RSExtras.h"

@implementation UITextView (RSExtras)

static BOOL stringCharacterIsAllowedAsPartOfLink(NSString *s) {

  /*[s length] is assumed to be 0 or 1. s may be nil.
   Totally not a strict check.*/

  if (s == nil || [s length] < 1) {
    return NO;
  }

  unichar ch = [s characterAtIndex:0];
  return ![[NSCharacterSet whitespaceAndNewlineCharacterSet] characterIsMember:ch];
}

- (NSString *)rs_potentialLinkAtPoint:(CGPoint)point {

  /*Grow a string around the tap until hitting a space, cr, lf, or beginning or end of document.*/

  /*If we don't check for end of document, then you could tap way below end of text, and it would return a link if the last text was a link. This has the unfortunate side effect that you can't tap on the last character of a link if it appears at the end of a document. I can live with shipping that.*/

  UITextRange *textRange = [self characterRangeAtPoint:point];
  UITextPosition *endOfDocumentTextPosition = self.endOfDocument;
  if ([textRange.end isEqual:endOfDocumentTextPosition])
    return nil;

  UITextPosition *tapPosition = [self closestPositionToPoint:point];
  if (tapPosition == nil)
    return nil;

  NSMutableString *s = [NSMutableString stringWithString:@""];

  /*Move right*/

  UITextPosition *textPosition = tapPosition;

  BOOL isFirstCharacter = YES;

  while (true) {
    UITextRange *rangeOfCharacter =
        [self.tokenizer rangeEnclosingPosition:textPosition withGranularity:UITextGranularityCharacter inDirection:UITextWritingDirectionNatural];
    NSString *oneCharacter = [self textInRange:rangeOfCharacter];

    if (isFirstCharacter) {
      /*If first character is cr or lf, then we're off the right hand side of the link. Maybe way outside.*/
      if ([oneCharacter isEqualToString:@"\n"] || [oneCharacter isEqualToString:@"\r"])
        return nil;
    }

    isFirstCharacter = NO;

    if (!stringCharacterIsAllowedAsPartOfLink(oneCharacter))
      break;
    [s appendString:oneCharacter];

    textPosition = [self positionFromPosition:textPosition offset:1];
    if (textPosition == nil)
      break;
  }

  /*Move left*/

  textPosition = [self positionFromPosition:tapPosition offset:-1];
  if (textPosition != nil) {

    while (true) {
      UITextRange *rangeOfCharacter =
          [self.tokenizer rangeEnclosingPosition:textPosition withGranularity:UITextGranularityCharacter inDirection:UITextWritingDirectionNatural];
      NSString *oneCharacter = [self textInRange:rangeOfCharacter];

      if (!stringCharacterIsAllowedAsPartOfLink(oneCharacter))
        break;
      [s insertString:oneCharacter atIndex:0];

      textPosition = [self positionFromPosition:textPosition offset:-1];
      if (textPosition == nil)
        break;
    }
  }

  return s;
}

- (NSArray *)rs_links:(NSString *)string {
  NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink
                                                             error:nil];

  return [detector matchesInString:string
                           options:0
                             range:NSMakeRange(0, [string length])];
}

- (NSString *)rs_linkAtPoint:(CGPoint)point {
  NSString *potentialLink = [self rs_potentialLinkAtPoint:point];
  if (potentialLink == nil || [potentialLink length] < 1) {
    return nil;
  }

  NSArray *links = [self rs_links: potentialLink];

  if (links == nil || [links count] < 1) {
    return nil;
  } else {
    return links[0];
  }
}

@end