Re: Get selected NSManagedObject from a NSPopUpButton
Re: Get selected NSManagedObject from a NSPopUpButton
- Subject: Re: Get selected NSManagedObject from a NSPopUpButton
- From: "Marcus S. Zarra" <email@hidden>
- Date: Sat, 8 Oct 2005 14:09:37 -0600
[controller setSelectedObjects:[NSArray arrayWithObject:yourSelection]];
Generally it is cleaner to manipulate the controllers instead of the
GUI elements, at least that is what I have figured out so far :)
On 10/8/05, Gian Marc Cadosch <email@hidden> wrote:
> Thank you for the solution, that works great! Now I'd like to ask you
> how you implement the reverse case, that is to set the Popup Button
> from a given NSManagedObject. I currently use selectItemWithTitle on
> the Popup Button and that works (at least as long as the names are
> unique). But I'm sure there is a proper solution...
>
> Marc
>
>
> > That seems like more work than is necessary since you can simply call:
> >
> > [[controller selectedObjects] objectAtIndex:0];
> >
> > Checking the count prior to that if it is possible that nothing is
> > selected.
> >
> > Why retrieved all of the objects in the controller when you can just
> > retrieve the selected objects which in this case would always be a
> > single object (or nil)?
> >
> > Using selectedObjects: would eliminate your step two completely and
> > make your step three cleaner. Although I do like the idea of adding a
> > category to retrieve a single object, makes the code a little cleaner.
> >
> > On 10/8/05, Niko Matsakis <email@hidden> wrote:
> >
> >> More specifically, what I do is this:
> >>
> >> 0. Bind the values binding from button to controller
> >> 1. Bind the "selectedIndex" from the button to the controller's
> >> selectedIndex
> >> 2. To get the current selected item, do either:
> >>
> >> [controller selection]
> >>
> >> or
> >>
> >> [[controller arrangedObjects] objectAtIndex:[controller
> >> selectionIndex]];
> >>
> >> For part 2, the two choices are basically equivalent, but the former
> >> returns a proxy and the latter returns the actual NSManagedObject, so
> >> I prefer the latter. In fact, I have created a handy category for
> >> it:
> >>
> >> @implementation NSArrayController (XXX)
> >>
> >> - (id) selectedObject
> >> {
> >> unsigned int selidx = [self selectionIndex];
> >> if (selidx != NSNotFound)
> >> return [[self arrangedObjects] objectAtIndex:selidx];
> >> return nil;
> >> }
> >>
> >> @end
> >>
> >> There may be a better way to do this, but this is the best one I have
> >> found. It also does not involve having any IBOutlets pointing to the
> >> actual NSPopUpButton, which seems clean to my sensibilities.
> >>
> >>
> >>
> >> Niko
> >>
> >>
> >>
> >> On Oct 8, 2005, at 4:25 PM, Marcus S. Zarra wrote:
> >>
> >>
> >>> Make sure you have a reference to the NSArrayController then you can
> >>> call selectedObjects on the array controller which will give you the
> >>> selected objects as an array.
> >>>
> >>> On 10/8/05, Gian Marc Cadosch <email@hidden> wrote:
> >>>
> >>>
> >>>> I've found lots of good information for programming core data
> >>>> applications. But now I have a problem for which I haven't found a
> >>>> solution yet:
> >>>>
> >>>> I'd like to get the managed object which is selected in a
> >>>> popupmenu.
> >>>> The popup menu is bound to an NSArrayController which receives the
> >>>> data from core data.
> >>>>
> >>>> Thanks for helping.
> >>>>
> >>>> Marc
> >>>> _______________________________________________
> >>>> Do not post admin requests to the list. They will be ignored.
> >>>> Cocoa-dev mailing list (email@hidden)
> >>>> Help/Unsubscribe/Update your Subscription:
> >>>>
> >>>> This email sent to email@hidden
> >>>>
> >>>>
> >>>>
> >>> _______________________________________________
> >>> Do not post admin requests to the list. They will be ignored.
> >>> Cocoa-dev mailing list (email@hidden)
> >>> Help/Unsubscribe/Update your Subscription:
> >>>
> >>> This email sent to email@hidden
> >>>
> >>>
> >>
> >>
> >
>
> _______________________________________________
> Do not post admin requests to the list. They will be ignored.
> Cocoa-dev mailing list (email@hidden)
> Help/Unsubscribe/Update your Subscription:
>
> This email sent to email@hidden
>
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden