NSArrayController: Doesn't update bold attribute - arrays

Question

I have a tableview bound to a NSArrayController. The ArrayController gets it´s data from an array [NSObject]:
class Fruits : NSObject {
var name:String
var price:Double
// If I set 'isBold = true' here manually,
//the font in my tableview becomes bold (from start of the application).
dynamic var isBold = false {
didSet {
print(isBold)
}
}
override init() {
name = "name"
price = 0.0
}
init(name:String, price:Double) {
self.name = name
self.price = price
}
}
So everything works fine as long as I set the ìsBold`value manually.
If I call in ViewController:
Fuits.init().isBold = true
tableView.reloadData()
The correct ìsBold`value is printed, but in the tableview nothing changes. Any ideas why the ArrayController doesn't notice the updated value?
EDIT:
I found a way how it is working. But maybe just a hint why it is not working like above. This solution works with iteration, I don´t think it is how it's supposed to be.
func changeBold(bold: Bool) {
if bold == false {
self.dataArray.forEach { fruit in
fruit.isBold = false
} else {
self.dataArray.forEach { fruit in
fruit.isBold = true
}
}
}

Answer 1

Edit: I misinterpreted what you had written. I thought the bindings settings panel was for the table view, not the table cell view. The rest of what you wrote makes more sense to me.
Your line Fruits.init().isBold = true is a bit odd syntax-wise, but the bigger point is that you're creating a new instance of Fruits and setting its bold attribute but not doing anything with the instance, so it goes away once it's out of scope. You need to change the property of the instance stored in the cell view's objectValue property (because that's the instance that's set by the bindings mechanism, which your cell view represents).
Also, be aware that "editing an object behind the controller's back" will also usually cause the symptom of changes not appearing in the UI. Example: if you remove an instance of Fruits from your array directly, you'd have to tell the array controller to refresh to see the changes (which can lose selection and scroll information in a table or some other UI state). Instead, you should access the array controller's arrangedObjects property and remove / add / insert there so the array controller is "aware" of the changes. You'll need to read a lot more on the bindings mechanism to understand when / why to make changes through a controller vs. directly, but it's an aspect of Cocoa Bindings of which you must be aware.