how to rebind nstableview IN COCOA - macos

I have a NSTableView and a NSArrayController for the NSTableView.
there is only one column in the table,"name"
at first, user open one file, in the arrayController will be #[#{#"name":#"1"},#{#"name":#"2"}]
after sometime, the user opened another file, now the content of array controller should be #[#{#"name":#"x"},#{#"name":#"y"},#{#"name":#"z"}].
how can I bind the new data to the NSTableView,(not add)?

You don't need to do anything if you have the bindings set up right. The content array of the array controller should be bound to an array (the one you show in your post), so when you change, or add to that array, the array controller's arranged objects will automatically change -- this doesn't require any "rebinding".

Related

Why is an NSArrayController allowing removal of objects when there's no NSTableView selection?

I have a Core Data app I'm building for OS X. My xib file has an NSArrayController that is bound to the AppDelegate's managed object context. The NSTableView in the window is bound to the array controller's arrangedObjects. The individual columns are bound to the appropriate properties of the array controller's entity, and almost everything is working fine. Except that there's a button on the layout for removing objects which works even when there's no object selected.
It's target is the array controller's remove: action and its Enabled binding is set to the array controller's canRemove key.
My guess is that there's some configuration of the array controller that I need to set so that it disallows removal of objects unless there's a selection, but I can't seem to find it.
What do I have to do to make is so that the array controller won't allow an object to be removed unless there's a selection in the table view?
Yes there is addition thing you need to do in the configuration.
You need to bind the button to Enable property - > Array Controller -> Selection - > Model Keypath -> "#count"..
Below is the image which will help you to fix this issue.
Buttons binding on selection is shown in the image below
It turns out that in addition to the bindings I mentioned, the NSTableView also needs to be bound. Binding its Selection Indexes to the Array Controller.selectionIndexes solved the problem.

Sharing NSArrayController Between Nibs

I have an Core Data-based iTunes-like app I'm building that has an NSTableView in the main window and allows the user to select items in the table view and perform a "get info", like in iTunes. Currently I'm working on the single-item get info window, which displays when the user selects a single item in the main window (which is in MainMenu.xib) and pressed Cmd-I. This brings up the single-item get info window (in SingleItemGetInfo.xib).
The table view in the main window is populated via bindings to an NSArrayController. If I put an NSArrayController into the SingleItemGetInfo.xib file, I understand that's going to be a different instance of NSArrayController.
So, what's the proper way to bind the fields in the single item get info window to the selection the user has made in the main window's table view?
MainMenu.xib's Array Controller bindings:
Managed Object Context: AppDelegate.self.managedObjectContext
MainMenu.xib's Table View bindings:
Content: Array Controller.arrangedObjects
Selection Indexes: Array Controller.selectionIndexes
Sort Descriptors: Array Controller.sortDescriptors
This will work mostly the same way it does when the master and detail views are in the same window. The primary difference is that you need to bind the selection of the array controller in the detail xib to the selection of the master array controller.
It depends on how you have your app organized as to how you accomplish this. If both views are run by the same object then you can just make the master array controller an outlet connected to the controller (#property IBOutlet NSArrayController *masterArrayController;). Then in the detail xib you can bind the selection of the detail array controller to the selection of the master array controller.
If each view has its own controller you might also consider just passing the managed object from the master view to the detail view. Then you can bind to each of the attributes of the managed object in your xib file (i.e. bind to File's Owner self.detailObject.fullName). If you pass a reference I think all of the changes will go right back into the managed object context.

What's the Difference between "Content Values" and "Content Objects"

I'm exploring bindings right now, and have an NSPopUpButton -
It presents me a number of options for bindings under Value Selection - Content, Content Objects, Content Values, and then Selected Object, Selected Value, and Selected Tag. Could someone please explain the difference between these?
Those are explained in the Cocoa Bindings Reference for NSPopUpButton, although that reference is not quite clear.
Content is an array controller that provides elements to the popup button. The array controller should be bound to an array. In order to determine how each element in the array is shown in the popup button, -description is sent to each object in the array.
You may customise this in two ways:
If you want the Selected Object binding to provide an object distinct from the array elements managed by the array controller to which Content was bound, you can bind Content Objects to another array controller. It could also be the same array controller but with a different key path;
If you want the popup button options to be something different than the description of each element in the array managed by the array controller to which Content was bound, you can bind Content Values to another array controller that manages an array whose elements contain the popup options. It could also be the same array controller but with a different key path.
A simple example: suppose you have the following class:
#interface Customer : NSObject
#property (copy) NSString *name;
#property (copy) NSString *phoneNumber;
#end
and you haven’t overridden the -description method. In this case, -descriptionis useless and the name property would be a good choice for the popup options. You’d bind:
Content to an array controller that manages an array of Customer instances, controller key arrangedObjects;
Content Values to the same array controller, controller key arrangedObjects, model keypath name.
You can then bind Selected Object to something else, for example a property in your application delegate or window controller. Cocoa bindings would then assign the selected Customer instance to that property.
Now suppose you are not interested in the whole Customer object that’s been selected, but only its phone number. In this case, you can bind Content Objects to the same array controller, controller key arrangedObjects, model keypath phoneNumber. When a popup option is selected, Cocoa bindings will set phoneNumber instead of an entire Customer instance. In summary: if you don’t bind Content Objects, Selected Object represents the original object in the array. If you bind Content Objects, then Selected Object can be something different.
You’d bind Selected Value if you were not interested in the original objects (or the content objects), but the actual strings shown in the popup options according to the Content Values bindings.
Quick recipe for providing data to the popup button:
Bind Content if you have objects (not only strings) that represent the popup options;
Bind Content Values if the options that are shown to the user cannot be obtained via Content by sending -description to the array elements;
Bind Content Objects if you want Selected Object to return something different from the array elements from Content.
Quick recipe for obtaining the current selection in a popup button:
Bind Selected Object if you want to know the full object (either from Content or Content Objects) representing the current popup selection;
Bind Selected Value if you only want the string that’s currently selected in the popup.
And lastly, you’d use Selected Tag if the popup options are actually taken from a menu whose items have a tag set.
#Object refers to any KVC-compliant object. #ObjectValue refers to the key path used to get the value from that object.
So, for your pop-up binding, ContentObjects would be bound to, say, an NSArrayController's arrangedObjects. Say this refers to an array of dictionaries or managed objects. You can't meaningfully present a dictionary in a pop-up (you get the start of the description output, e.g <NSCFDictionary... or similar), so this is where the contentValues binding comes in. This would be something like your NSArrayController's arrangedObjects.name, where name is a key from your dictionary or managed object.
I hope this helps, I struggled with the same concept myself when I started with bindings.

NSTableView bindings how to add a row

I'm working on a application with the this interface (sorry the language is Dutch):
http://www.flickr.com/photos/pluueer/5756159100/
The Add function (incl. the four NSTextFields) under the NSTableView are to moved to a sheet someday, but for now this is fine. I've set up bindings according to a tutorial (http://cocoadevcentral.com/articles/000080.php), but the tutorial doesn't supply how to add rows in the way I want to (just adds an empty row which you need to edit in the NSTableView).
I've got a connection between the 'Voeg toe' (Dutch for 'Add') button and the Array Controller. But after clicking I get the message:
2011-05-28 23:37:56.149 Hop Calc[4345:a0f] -[__NSPlaceholderDictionary initWithObjects:forKeys:]: number of objects (0) not equal to number of keys (4)
It makes sense, because I've not implemented anything for adding rows, but I just don't know how.
"Add a row to the table" is the wrong way to think of it. Your table represents a collection and a controller provides the information to the table, mediating between the table (view) and the collection (model). Since you mentioned bindings, the collection is likely managed by an NSArrayController. So you want to add a new object (of the kind your array controller manages) to the array controller's content array.
Simplest way: Connect the Add button to the -add: action of the NSArrayController. It'll add an empty row.
If you want more control, connect the Add button to your own custom action in some controller. That action will create an instance of whatever's represented by your array controller, prepopulate it (or whatever you want to do), then, using an outlet it holds to your NSArrayController, will call the array controller's -addObject: method to add the object (the possibly a -rearrangeObjects call to get the array controller to re-sort its contents).

Populating an NSPopUpButtonCell with string values

I am trying to populate a NSPopUpButtonCell with a list of strings. In -(init), I populate an NSArray with the values I want in the PopUp Button. How do I connect this to the NSArrayController I added in IB? Does my app delegate need an IBOutlet NSArrayController to connect to or is there a way to bind it?
Also, when I bind the NSArrayController to the NSPopUpButtonCell, do which Content do I bind it to? Content or Content Values?
jorj
Bind the array controller's Content Array to your controller's array of strings. Bind both the pop-up button cell's Content and Content Values to your array controller's arrangedObjects.
Presumably, you also want to know which of these strings is selected. To do that, bind the pop-up button cell's Selected Object (which will be one of the objects in Content) to a property of your controller (the one that owns the original array).

Resources