How to use NSViewController in an NSDocument-based Cocoa app

Question

I\'ve got plenty of experience with iOS, but Cocoa has me a bit confused. I read through several Apple docs on Cocoa but there are still details that I could not find anywhe

Answer 1

I haven't dived into storyboards but here is how it works:

If your app has to support 10.9 and lower create custom of subclass NSWindowController

Put code like this into NSDocument subclass

- (void)makeWindowControllers
{
  CustomWindowController *controller = [[CustomWindowController alloc] init];
  [self addWindowController:controller];
}

If your app has multiple windows than add them here or somewhere else (loaded on demand) but do not forget to add it to array of document windowscontroller (addWindowController:)

If you create them but you don't want to show all the windows then override

- (void)showWindows
{
  [controller showWindow:nil]
}

You can anytime access you model in your window controller

- (CustomDocument *)document
{
  return [self document];
}

Use bindings in your window controller (windowcontroller subclass + document in the keypath which is a property of window controller)

[self.textView bind:@"editable"
                  toObject:self withKeyPath:@"document.readOnly"
                   options:@{NSValueTransformerNameBindingOption : NSNegateBooleanTransformerName}];

In contrast to iOS most of the views are on screen so you have to rely on patterns: Delegation, Notification, Events (responder chain) and of course MVC.

10.10 Yosemite Changes:

NSViewController starting from 10.10 is automatically added to responder chain (generally target of the action is unknown | NSApp sendAction:to:from:) and all the delegates such as viewDidLoad... familiar from iOS are finally implemented. This means that I don't see big benefit of subclassing NSWindowCotroller anymore.

NSDocument subclass is mandatory and NSViewController is sufficient.

You can anytime access you data in your view controller

- (CustomDocument *)document
{
  return (CustomDocument *)[[NSDocumentController sharedDocumentController] documentForWindow:[[self view] window]];
  //doesn't work if you do template approach
  //NSWindowController *controller = [[[self view] window] windowController];
  //CustomDocument *document = [controller document];
}

If you do like this (conforming to KVC/KVO) you can do binding as written above.

Tips: Correctly implement UNDO for your model objects in Document e.g. or shamefully call updateChangeCount:

[[self.undoManager prepareWithInvocationTarget:self] deleteRowsAtIndexes:insertedIndexes];

Do not put code related to views/windows into your Document

Split your app into multiple NSViewControllers e.g.

- (void)prepareForSegue:(NSStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:AAPLListWindowControllerShowAddItemViewControllerSegueIdentifier]) {
        AAPLListViewController *listViewController = (AAPLListViewController *)self.window.contentViewController;

        AAPLAddItemViewController *addItemViewController = segue.destinationController;

        addItemViewController.delegate = listViewController;
    }
}

Previous code is called on windowcontroller with viewcontroller as delegate (again possible only after 10.10)

I always prefer to use multiple XIBs rather than one giant storyboard/XIB. Use following subclass of NSViewController and always inherit from it:

#import 

@interface MyViewController : NSViewController

@property(strong) IBOutlet NSView *viewToSubstitute;

@end

#import "MyViewController.h"

@interface MyViewController ()

@end

@implementation MyViewController

- (void)awakeFromNib
{
  NSView *view = [self viewToSubstitute];
  if (view) {
    [self setViewToSubstitute:nil];
    [[self view] setFrame:[view frame]];
    [[self view] setAutoresizingMask:[view autoresizingMask]];
    [[view superview] replaceSubview:view with:[self view]];

  }
}

@end

1. Add a subclass of MyViewController to the project with XIB. Rename the XIB
2. Add NSViewController Object to the XIB and change its subclass name
3. Change the loading XIB name to name from step 1
4. Link view to substitute to the view you want to replace Check example project Example Multi XIB project

Inspire yourself by shapeart or lister or TextEdit

And a real guide is to use Hopper and see how other apps are done.

PS: You can add your views/viewcontroller into responder chain manually.

PS2: If you are beginner don't over-architect. Be happy with the fact that your app works.