Re: CoreData - calculations in tables?
Re: CoreData - calculations in tables?
- Subject: Re: CoreData - calculations in tables?
- From: Charilaos Skiadas <email@hidden>
- Date: Wed, 6 Jul 2005 01:28:23 -0500
On Jul 6, 2005, at 12:40 AM, Alan Dail wrote:
I am building an app with CoreData and have run into a couple of
issues.
I have a view with two tables, each with their own
NSArrayController. Using bindings, the content set of the 2nd
controller is the selection of the first controller. i.e. the
first table is a list of people, the 2nd list is a list of items
for the selected person. When I select a person, I can add or
delete items for that person. What I wanted to do, though, is add
a column to my table that has the number of items for each person.
The first thing I tried was to simply copy the way the # out of #
display is generated when you create a defeault core data view -
i.e. I mapped a table column to items.@count - this actually
displays the item count for each person, but does not update when
items are added or removed and caused all sorts of problems if i
added items to the main list as a result of notifications.
What sorts of problems? I usually find useful answers to such
problems by googling for the exception that was thrown in the console.
As a possible solution, maybe you could set the "Continuously updated
value" checkbox at the right place?
How should I be doing things like this. In addition to a simple
total, I'd also like to be able to do other calculations on items
in the list. For instance, if they have an attribute that is a
number, I'd like to be able to have the main list give a total
amount from summing all of the items in the sublist.
I think this came up in the past, I had a very similar problem
yesterday. I think this might answer your question, it did in my case:
http://www.cocoabuilder.com/archive/message/2005/5/18/136314
Alan
Haris
_______________________________________________
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