How do I load another view controller from the current view controller's implementation file?

Question

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.

So, I have created the frontend and the backend of the login form, it works. I have an action which is triggered by the "Log in" button which verifies the credentials and either trigger a error either presents the Google Map.

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.

My question is how can I load another view controller from an action placed in the implementation file of the current view controller?

Now, I have this code:

UIViewController *mapViewController =
                [[BSTGMapViewController alloc] initWithNibName:@"BSTGMapViewController"
                                                           bundle:nil];

How can I make it the "root view controller" of the window and maybe featuring a transition (considering my logic is ok)?

Answer 1

If you want to open the ViewController from another one then you should define it like this in your IBAction . It is good idea to make the viewController as property though.

FirstViewController.h

@class SecondViewController;

@interface FirstViewController : UIViewController

@property(strong,nonatomic)SecondViewController *secondViewController;
@end

FirstViewController.m

-(IBAction)buttonClicked:(id)sender{
    self.secondViewController =
                    [[SecondViewController alloc] initWithNibName:@"SecondViewController"
                                                               bundle:nil];
   [self presentViewController:self.secondViewController animated:YES completion:nil]; 

}

You should make a viewController as rootViewController in your AppDelegate class something like this

YourFirstViewController *firstViewController=[[YourFirstViewController alloc]initWithNibName:@"YourFirstViewController" bundle:nil];

self.window.rootViewController=yourFirstViewController;