Modal UIViewController appears blank - ios

Question

I'm appending code to an existing app to add a modal loginView, the old project does not use xib, and the new view controller does.
The present project load its rootViewController this way
- (void) loadView
{
// this should take up the entire screen...
UIView * view = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];
view.backgroundColor = [UIColor blueColor];
self.view = view;
sideBar =
[[SideBarView alloc] init];
sideBar.rootViewController = self;
[self.view addSubview:sideBar];
pageView =
[[PageView alloc] initWithTitle:DataEntryTitle
client:client];
pageView.rootViewController = self;
//I added this to instantiate the new view controller
_aLoginView = [[LoginViewController alloc]initWithUser:aUser];
[self.view addSubview:pageView];
}
To launch the modal view controller I'm using this code.
-(void)viewDidAppear:(BOOL)animated{
_aLoginView.modalPresentationStyle = UIModalPresentationFormSheet;
[self presentViewController:_aLoginView animated:YES completion:nil];
}
As long as I understand the reason for the modal LoginView appearing blank is that I'm creating a new instance of it, instead of calling the existing xib definition. Does someone know what should I do to reference the xib? The old project does not use storyboard, nor xib files.
Thanks,
With your info I think I'm doing something wrong in LoginViewController.m, but I don't know exactly what.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (id)initWithUser:(verifyUser *)aUser
{
self = [super initWithNibName:#"LoginViewController" bundle:[NSBundle mainBundle]];
if (self) {
// Custom initialization
_UserModel = aUser;
}
return self;
}

Answer 1

You want to create the view controller by loading it from the nib
[[LoginViewController alloc] initWithNib:#"nib file name" bundle:[NSBundle mainBundle]]];
If you want to keep your initWithUser: initializer you should be able to do
self = [super initWithNib:#"nib file name" bundle:[NSBundle mainBundle]];

Answer 2

The files owner of your xib is not set.
Open your xib and select the file owner option in the top left
Then on the right pane set the files owner to your view controller:
FOOTNOTE
As an aside, you don't need to set the frame of your view controller in viewDidLoad. It isn't a ViewControllers responsibility to evaluate its own size. A view controller is merely responsible for maintaining the relationship between the model and the view. It is the responsibility of the container or parent ViewController to set the size.
Happy coding