How do you Sort Bound Data in NSTableColumn using InterfaceBuilder binding?

Sorting Bound Data in NSTableColumn using IB binding.

Keys: NSTableColumn , sorting, NSArrayController, Content Set

A contentSet serves like a data source for a TableColumn

This deals with a SplitView with two single column NSTableViews The names of the TableViews are BookCategory and Books. The Books Table has a single column with book_titles. The Class BookCategory has a one to many relationship to Book.

The BookCategory Table is sorted at load using:

@implementation MyBookCategoryController

- (id)init
{
    self = [super init];
    if (self) {
        // Initialization code here.
       NSSortDescriptor *descript = 
       [NSSortDescriptor sortDescriptorWithKey:@"name"
                    ascending:YES selector:@selector(caseInsensitiveCompare:)];

       [self setSortDescriptors:[[NSArray arrayWithObject:descript] autorelease] ];

    }
    return self;
}

---

This same approach fails to sort the BookTitle table at load.  !!

The BookTitle table/column loads unsorted.

For the TableColumn the Attributes Inspector has  
 Sort Key:title
 Selector: caseInsensitiveCompare:
 Order: Ascending

This appears to enable the sorting when one clicks on the column header.

I want the data sorted when the view loads. 

The binding inspector for this book_title column has:
 Value : BookCategoryArrayController.arrangedObjects.name

The BookTitleArrayController in binding inspector shows 
 Content Set: Book Category ArrayController.selection.books

To restate the problem, the tableview with the book titles load unsorted. It sorts only after the user's FIRST click on the column header.

Say there are three book categories Art, History, Sports. When the app loads the left table in the splitview is sorted, that is :

Art
History
Sports

When the user selects ANY category, titles for all books in the category appear in the right tableView but unsorted. If the user clicks on the Header of the book_title TableColumn the initial sorting is done on the column. Thereafter the selection of ANY book category causes a sorted display of book_titles in the right tableView. That is, ONLY the first selection of a category results in an Unsorted book title list.

Thanks a lot for reading, Mark

This is an outline of what finally worked for me.

            Sorting with CategoryArrayController (NSArrayController)

      Bindings Inspector
         Content Set  Bind to: CategoryArrayController.selection.books

         SortDescriptors Bind to: ShareUserDefaultsController
          Controller Key: values
          sortDescriptors  (note:  exclamation point)
          NSUnarchiveFromData

    Shared User Defaults Controller 
        Referencing Outlets
          userDefaultsController -- AppController (C:AppController)
        Referencing Bindings
            values.sortDescriptors -- Sort Descriptors Rx Array Controller (C:NSArrayController)
                                   -- Sort Descriptors Category Array Controller (C:NSArrayController)  

      Clicking on Category Header does no sort. Selects all in Cats, and empties Recipe Table
      Comments on the above welcome.

    TableViewCat (NSTableController)
        Attributes Inspector
          TableView
            Selection 
                Empty,Column,Type Select
          Control
             State.Enabled
        Connections Inspec
            None
        Bindings Inspec
            None

      TableColumn -Category (NSTableColumn)
        Attributes Inspec
            Sort Key : None
        Bindings Inspec
            Value -- Category Array Controller.arrangedObjects.name


    Sorting with RxArrayController (C:NSArrayController)
      Attributes Inspec
         Array Controller: 1-5 of 6
         Object Controller
           EntityName: Recipe
             Prepares Content
             Editable
      Connections Inspector
        Referencing Bindings
          arrangedObjects.name -- Value - Table Column Recipe
          selectedObjects      -- Double Click Argument - Table View Book
      Bindings Inspector
       Controller Content
         Content Set
           Category Array Controller.selection.books
       Controller Content Parameters    
         Sort Descriptors Bind to: ShareUserDefaultsController
          Controller Key: values
          sortDescriptors  (note:  exclamation point)
          NSUnarchiveFromData
        Parameters  
          Managed Object Context(App Delegate.manangedObjectContext

    TableView Book (NSTableView)
        Attributes Inspector
          TableView
            Selection Empty,Column,Type Select
          Control
            State.Enabled
        Connections Inspec
            Bindings
                DoubleClick Argument -- Book Array Controller.selectedObjects
                Double Click Target  -- App Delegate.self
        Bindings Inspec
            Double Click Argument (Book Array Controller.selectedObjects)
            Double Click Target (App Delegate.self)
                Bind To: App Delegate
                    Model Key Path: self  (Repeats ?)
                    Selector Name: newBookAction: 
                      Conditionally Sets Enabled

      TableColumn - Book (NSTableColumn)
        Attributes Inspec
            Sort Key : None
        Connections Inspec
            Bindings
                Value -- Book Array Controller.arrangedObjects.name
        Bindings Inspec
            Value -- Book Array Controller.arrangedObjects.name