macOS Core Data, how to refresh views after object save?

[gigantor]

Hi,

I have a basic core data app with a view using core data bindings to display fields of a managed object. When the object is saved via APIs the bound data used core data bindings does not refresh.

How do I update/refresh views following a core data object save ?

 

[Littleodie914]

It's been a while, but...

It really depends on the class of the view you're updating. An NSView, for example, would be best updated calling:

[myView setNeedsDisplay];

While an instance of NSTableView would be updated calling:

[myTableView reloadData];

 

[gigantor]

Thanks for that but I was wondering if there was a way to cause the refresh from the Core Data layer upwards rather than from the GUI View layer.

I guess I am looking for a way for Core Data managed objects to notify interested views etc when data in a managed object changes, ie in my case, saving an updated managed object would cause views with bindings to that managed object to get notified to refresh their displays.

Does anyone know of an existing mechanism on Cocoa or core data to do this ?

 

[HiRez]

Is the saving of a Core Data object separate from updating bindings? Don't the bindings get updated when the managed object changes in the context instead of when it gets saved back to storage from the context (and then undone if changes are not saved)?

Anyway, if you are setting data programmatically, can you wrap the changes in NSObject's -willChangeValueForKey: and -didChangeValueForKey: calls to trigger propogation of the changes to your view objects? I dunno, that might work.

 

[gigantor]

Hi,

I got the issue solved. My program had inadvertently created a separate NSManagedObjectContext object seperate from the instance used by the interface builder generated classes.

Once I updated the code to use the context created in the Interface Builder class then everything worked as expected. Updating and saving a managed object programmatically caused the GUI to update automatically as expected.

Regards,
Gigantor