title: Ask user to do login first before Facebook Share
body: <p>I have to follow below requirement to do Facebook share:</p>
  
  <ol>
  <li>If user is logged in Facebook app, just ask them to do share with dialog popup.</li>
  <li>If user is not logged-in to Facebook app, ask them to do login first and then show the share dialogue.</li>
  </ol>
  
  <p>I'm using below code to show share dialogue.</p>
  
  <pre><code>FBSDKShareLinkContent *content = [[FBSDKShareLinkContent alloc] init];
  content.contentURL = [NSURL URLWithString:permalink];
  content.contentDescription = [NSString stringWithFormat:@"%@",smallDescription];
  content.imageURL = [NSURL URLWithString:[NSString stringWithFormat:@"%@",guid]];
  
  [FBSDKShareDialog showFromViewController:self
                               withContent:content
                                  delegate:nil];
  </code></pre>
  
  <p>Above code works when user is logged in but if not logged in it's shows alert message "You need to be logged into the Facebook app to share this link".</p>