refresh reference ManagedObjectContext - iphone

Question

in my iOS app i have a core data, and i have notice that sometime, in a specific view, when i retrieve information from core data, are not always up to date, i'm explain well:
if i update some value in the core data, and then i go in in a specific view to view this information, that information are not up to date, now i show how i access my database:
.h
#property (nonatomic, retain) NSManagedObjectContext *managedObjectContext;
.m
#synthesize managedObjectContext;
- (NSArray *)sortInformation{
if (managedObjectContext == nil) {
managedObjectContext = [(AppDelegate *) [[UIApplication sharedApplication] delegate] managedObjectContext];
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription
entityForName:#"MyEntity" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
....
and then i display my information in a table view, all work perfectly, there is only this problem, that SOME TIME seems that the update i have done in another view is not read in this view, but if i close the app, and i close it from the background, and then i reopen it all works fine...so i have saved the update in the core data correctly, so i think the problem is in this view, maybe i have an old reference of the core data and not the update version, maybe the problem is this:
if (managedObjectContext == nil) {
managedObjectContext = [(AppDelegate *) [[UIApplication sharedApplication] delegate] managedObjectContext];
}
that refresh only if the variable managedObjectContext is nil so only if the view is deallocated...so never, because is one of my root view controller in a UITabbarController, so my question is, how i can access to the core data to have always a update version of it?

Answer 1

no need to refresh the context just call save method on managedObjectContext like [managedObjectContext save];
or if you are using more than one managed object context you should merge changes done by the context

Answer 2

On the implementation of the database class you can do like this
-(id) initWithContext: (NSManagedObjectContext *)managedObjContext {
self = [super init];
[self setManagedObjectContext:managedObjContext];
return self;
}
the managedObjContext is pass and set
On your app delegate when call the database class it should be something like this
database = [[Database alloc] initWithContext:self.managedObjectContext];
Then you are good to accessed the database like this
- (NSArray *)sortInformation {
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"MyEntity" inManagedObjectContext:managedObjectContext];
[fetchRequest setEntity:entity];
NSMutableArray *mutableFetchResults = [[[managedObjectContext_ executeFetchRequest:request error:&error] mutableCopy] autorelease];
[request release];
return mutableFetchResults;
}