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In my first guide to binding, it uses NSFetchedResultsController, which is tightly coupled to the Core Data framework.

It is not necessary (of course) to bind to Core Data models.

This guide will be more generic, providing a guide to binding to a plain old object model.

The Model

Let’s use a simple model MyData.

class MyData: NSObject {
    @objc var name: String
}

Any member variable such as name has to be annotated with @objc, because that’s how the old world works and provides.

Array Controller

NSArrayController manages the models.

It does NOT hold the models, but simply manages it in terms of sorting, filtering, and CRUD operations.

It is common to add the NSArrayController object in a storyboard. Then set up as such:

• In Attributes Inspector:
  • Mode is class
  • Class name is MyApp.MyData
  • The prefix MyApp is necessary, and it is your target’s Product Module Name
• In Binding Inspector > Controller Content:
  • Bind to your view controller (usually) eg. MyListViewController
  • Model Key Path is self.myDataList

View Controller

It is a good time now to show you what your view controller looks like.

class MyListViewController: NSViewController {
    @objc dynamic var myDataList = [MyData]()
    @objc dynamic var sorts = [NSSortDescriptor]()
    @objc dynamic var filter: NSPredicate?
}

myDataList is the actual models that the view controller holds. It must be prefix with @objc once again.

Remember: The NSArrayController is managing these models. You don’t mutate the array controller directly.

Whenever you want to update your model, mutate myDataList.

Table View

Next, we bind the array controller to the table view.

1. In Attributes inspector, set Content Mode to View Based.
2. In Bindings inspector, bind Content to Array Controller. The Controller Key should already be arrangedObjects.
3. Select the actual view to bind eg. NSTextField, NSDatePicker etc
4. In Bindings inspector, bind Value to Table Cell View
5. Set the Model Key Path to objectValue.name (your model’s attribute!)

Sort & Filter

1. Select Array Controller > Bindings inspector > Sort Descriptors > Bind to the view controller
2. Set Model Key Path to self.sorts
3. Similarly, for filter bind to self.filter
4. Init sorts and filter in viewDidLoad
5. Mutate them, and the views will be updated immediately

Sort when clicking on the table column header

1. Select Table View > Bindings inspector > Sort Descriptors > Bind to the view controller
2. Set Model Key Path to self.sorts
3. Select a table column > Bindings inspector > Value > Bind to Array Controller
4. Set the model key path eg. “name”
5. Make sure Creates Sort Descriptor is enabled

Selection

When you select rows in the table view, you should bind it to the array controller too.

1. Select Table View > Bindings inspector > Selection Indexes > Bind to the Array Controller
2. Set Controller Key to selectionIndexes

Delete Selected Rows

@IBAction func deleteSelectedRows(_ sender: Any) {
    arrayController.remove(atArrangedObjectIndexes: arrayController.selectionIndexes)
}

I have omitted the obvious: Add a button with the action to the above function, adding the array controller outlet to the view controller.

Add New Row

Similarly, you can have a button to add new model(s).

@IBAction func add(_ sender: Any) {
    let newModel = MyData()
    arrayController.addObject(newModel)
}