title: How do I load another view controller from the current view controller's implementation file?
body: <p>I need to create an app which features a login/signup form and then a custom Google Map. I am new to iOS programming and trying to learn the things needed for this app very fast.</p>
  <p>So, I have created the frontend and the backend of the login form, it works. I have an action which is triggered by the &quot;Log in&quot; button which verifies the credentials and either trigger a error either presents the Google Map.</p>
  <p>I want to show that Google Map in another view controller which controls another xib file. I created the view controller and the xib file.</p>
  <p>My question is how can I load another view controller from an action placed in the implementation file of the current view controller?</p>
  <p>Now, I have this code:</p>
  <pre><code>UIViewController *mapViewController =
                  [[BSTGMapViewController alloc] initWithNibName:@&quot;BSTGMapViewController&quot;
                                                             bundle:nil];
  </code></pre>
  <p>How can I make it the &quot;root view controller&quot; of the window and maybe featuring a transition (considering my logic is ok)?</p>