UITextView link is clickable, but when I click it, Safari doesn't open

Question

I have set this two important variable for clickable link, but when I click the content link in the UITextView, Safari doesn't open.

Anybody know what the problem is?

@property (strong, nonatomic) UITextView *attachmentDescription;

{
    self.attachmentDescription.editable = NO;
    self.attachmentDescription.dataDetectorTypes =UIDataDetectorTypeLink;
}