Fetch with IB and programmatic predicates
Fetch with IB and programmatic predicates
- Subject: Fetch with IB and programmatic predicates
- From: Kevin Hoctor <email@hidden>
- Date: Wed, 28 Feb 2007 15:48:55 -0600
I have a program patterned after the Core Data example CoreRecipes. I
have a tree that imposes a predicate for a fetch using simple
reference to a "transactions" set. The program also filters using a
NSSearchField and that predicate combines nicely with the tree
selection.
Now I want to add a date range to the predicate (for now I am simply
using two NSDate entry fields on the window). How do I get the
predicate from these two entries to affect the
TransactionsArrayController? I have code to build a compound
predicate, but I can't get it to affect the controller data:
- (void)refreshDatePredicate
{
NSExpression *lhs = [NSExpression expressionForKeyPath:@"date"];
NSExpression *greaterThanRhs = [NSExpression
expressionForConstantValue:[fromDate dateValue]];
NSPredicate *greaterThanPredicate = [NSComparisonPredicate
predicateWithLeftExpression:lhs
rightExpression:greaterThanRhs
modifier:NSDirectPredicateModifier
type:NSGreaterThanOrEqualToPredicateOperatorType
options:0];
NSExpression *lessThanRhs = [NSExpression expressionForConstantValue:
[toDate dateValue]];
NSPredicate *lessThanPredicate = [NSComparisonPredicate
predicateWithLeftExpression:lhs
rightExpression:lessThanRhs
modifier:NSDirectPredicateModifier
type:NSLessThanOrEqualToPredicateOperatorType
options:0];
NSCompoundPredicate *predicate = [NSCompoundPredicate
andPredicateWithSubpredicates:[NSArray
arrayWithObjects:greaterThanPredicate, lessThanPredicate, nil]];
// None of these do anything to filter the data
// [transactionController fetchWithRequest:<#(NSFetchRequest *)
fetchRequest#> merge:<#(BOOL)merge#> error:<#(NSError * *)error#>
// [transactionController setFetchPredicate:predicate];
// [transactionController fetch:nil];
// [transactionTable needsDisplay];
}
Do I override fetchWithRequest:merge:error: or some other action? If
so, how do I do this without losing the clean predicate process that
is working via IB?
Thanks,
Kevin Hoctor
email@hidden
No Thirst Software LLC
http://nothirst.com
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden