I'm trying to send multiple localNofications using a fetch request on an entity
And though this code works fine
NSFetchRequest *myRequest = [[NSFetchRequest alloc] init];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"active == YES"];
[myRequest setEntity:[NSEntityDescription entityForName:#"Entry" inManagedObjectContext:managedObjectContext]];
[myRequest setPredicate:predicate];
NSError *error = nil;
NSArray *fetchedObjects = [self.managedObjectContext executeFetchRequest: myRequest error: &error];
if (fetchedObjects == nil){
// Deal with error...
}
// We fill the NSMutableArray with the values of the fetch
self.activeList = [[NSMutableArray alloc] initWithArray:[fetchedObjects valueForKey:#"textbody"]];
[self scheduleAlarms:[self.activeList objectAtIndex:0]];
[fetchedObjects release]; //this line crashes the app
1) if I release fetchedObjects, the app crashes. Aren't I supposed to release it ?
2) Could I use the localNotif.userinfo to optimize the code instead of calling a method to schedule each localNotification with the strings in my activeList ? I can't figure out how to do it.
Thanks,
Mike
1) executeFetchRequest returns an autoreleased NSArray, you don't need to release it manually
2) not clear what do you want to optimize...
Related
Below is my viewDidLoad method in a tableViewController. When viewDidLoad runs this error comes up
2014-03-03 12:44:54.904 SalesCRM2[30188:70b] -[_PFArray sortUsingDescriptors:]: unrecognized selector sent to instance 0x8c45710
2014-03-03 12:44:54.931 SalesCRM2[30188:70b] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[_PFArray sortUsingDescriptors:]: unrecognized selector sent to instance 0x8c45710'
on this line of code
[array sortUsingDescriptors:[NSArray arrayWithObject:sort]];
Here is the whole method
- (void)viewDidLoad
{
[super viewDidLoad];
JCAppDelegate *appDelegate =
[[UIApplication sharedApplication] delegate];
NSManagedObjectContext *context =
[appDelegate managedObjectContext];
NSEntityDescription *entityDesc =
[NSEntityDescription entityForName:#"Customers"
inManagedObjectContext:context];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:entityDesc];
NSError *error;
NSArray *objects = [context executeFetchRequest:request
error:&error];
NSMutableArray *array = (NSMutableArray *)objects;
NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:#"firstName" ascending:YES];
[array sortUsingDescriptors:[NSArray arrayWithObject:sort]];
if ([objects count] == 0)
{
//_isEmpty = YES;
}
else
{
//_isEmpty = NO;
_resultsArray = (NSMutableArray *)objects;
NSLog(#"resultsArray: %i",[_resultsArray count]);
// matches = objects[0];
// _address.text = [matches valueForKey:#"address"];
// _phone.text = [matches valueForKey:#"phone"];
// _status.text = [NSString stringWithFormat:
// #"%lu matches found", (unsigned long)[objects count]];
}
}
Read the error message. It's telling you the problem. You can say sortUsingDescriptors: to an immutable array. It is immutable.
Now, as for what you are doing wrong, it is much more interesting! You are saying:
NSMutableArray *array = (NSMutableArray *)objects;
Perhaps you believe that this turns an immutable array into a mutable array. It doesn't. You can't turn a silk purse into a sow's ear by typecasting. You may lie to the compiler (and you did, by typecasting to a false class), but you can't lie to the runtime. What an object is, that's what it is, no matter what you call it.
If you want a mutable array, you must make a mutable array (e.g. by calling mutableCopy) - it isn't enough to say a thing is a mutable array when in fact it isn't.
this is the code in my AppDelegate.m:
-(IBAction)fetch:(id)sender{
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Foo" inManagedObjectContext:[self managedObjectContext]];
[fetchRequest setEntity:entity];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"title == 'some title'"];
[fetchRequest setPredicate:predicate];
NSError *error = nil;
NSArray *fetchedObjects = [[self managedObjectContext] executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects == nil) {NSLog(#"Error: %#", error);}
NSMutableArray *fooArray = [[NSMutableArray alloc]init];
for (Foo *f in fetchedObjects) {
//here another fastenum for a to-many relationship
for(Bar *b in f.relationship){
[fooArray addObject:b.title];
}
}
Everytime I perform the fetch action, even if I've changed the app.storedata file via UI and checked the changes in finder, the result is always the same until i quit the application. After a restart, the fetch result is up to date and aligned with the app.storedata file. The fooArray count is always the same, regardless if I add some entries in the entities and coredata save everything.
I've tried with [fetchRequest setIncludesPendingChanges:YES] but it doesn't affect the behaviour.
How to update the fetch result while the app is running?
UPDATE: i've "solved" the problem with this workaround:
-(IBACTION)fetch:(id)sender{
_managedObjectContext = nil;
_persistenStoreCoordinator = nil;
//rest of the code...
Is this workaround a final solution? Is there a more "correct" way to solve this problem?
Hi I set up my own coredata app, or I tried...
First I created the xdatamodel and generated the Modelclasses, after this I implemented all the function of core-data in AppDelegate which I found in a generated project. Finally I copied the fetchedResultsController in my TableViewController.
fetchedResultsController
- (NSFetchedResultsController *)fetchedResultsController {
if (fetchedResultsController_ != nil) {
return fetchedResultsController_;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"ParameterGroup" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
[fetchRequest setFetchBatchSize:20];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:#"Root"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptor release];
[sortDescriptors release];
NSError *error = nil;
if (![fetchedResultsController_ performFetch:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return fetchedResultsController_;
}
First I checked if the managedObjectsController is != nil, it has a address
Then I copied the EntityName from my xdatamodel in entityForName,
but NSEntityDescricption entity is nil.
And if I just create a new object the exception says, that the entity doesn't exist
Do I have to connect the xdatamodel to my project?
Hope you can help me
Thanks a lot!!!
The most common cause of this problem is simply misspelling the entity name wrong in the code such that it doesn't match the entity name in the data model.
Copy and paste the entity name from the model to the code and see if that fixes the problem.
The simplest way to solve this, given that you haven't done a lot coding on non-core-data parts, is probably to create a new project where you check the box for "Use Core Data". If you're going to use a Navigation Bar, choose this as your template. If I recall correctly, this will generate a table view with all functions needed. You'll have to modify the datamodel (generated).
Remark that you'll have to delete the app from the Simulator if it is installed and you change the datamodel (otherwise the generated data will not be consistent with the datamodel and the app will crash)
I was make communication for client-server application and have strange problem.
here is a code where i pickup objects.
- (byref NSArray*)objectsOfName:(bycopy NSString*)name
withPredicate:(bycopy NSPredicate*)predicate;
{
NSManagedObjectContext *context = [self managedObjectContext];
NSError *error = nil;
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:[NSEntityDescription entityForName:name
inManagedObjectContext:context]];
[request setPredicate:predicate];
NSArray *results = [context executeFetchRequest:request error:&error];
[request release], request = nil;
if (error) {
NSLog(#"%#:%# Error on fetch %#", [self class], NSStringFromSelector(_cmd), error);
return nil;
}
//NSLog(#"%#:%# Result of fetch is %#", [self class], NSStringFromSelector(_cmd), results);
return results;
}
Here is pickup:
NSArray *destinations;
#ifdef SNOW_CLIENT
destinations = [server objectsOfName:#"DestinationsListWeBuy" withPredicate:predicate];
If i do
NSLog(#"Destination:%#\n",destinations);
i seen all objects in log.
If i try to do
NSLog(#"all:%#\n%#\n%#\n",[[destinations objectAtIndex:0] valueForKey:#"rate"],[[destinations objectAtIndex:0] valueForKey:#"lastUsedACD"],[[destinations objectAtIndex:0] valueForKey:#"lastUsedCallAttempts"]);
i seen attributes also.
But, if i try to do loop around objects:
for (NSManagedObject *dest in destinations)
{
NSLog(#"all:%#\n%#\n%#\n",[dest valueForKey:#"rate"],[dest valueForKey:#"lastUsedACD"],[dest valueForKey:#"lastUsedCallAttempts"]);
i have EXC_BAD_ACCESS in this part of code:
for (NSManagedObject *dest in destinations)
all debug technic, which i know, don't give me possibility to understand, what happened. (NSZombieEnabled = YES)
if i do loop at another manner:
for (NSUInteger count = 0;count < [destinations count]; count++)
NSLog(#"all:%#\n%#\n%#\n",[[destinations objectAtIndex:count] valueForKey:#"rate"],[[destinations objectAtIndex:count] valueForKey:#"lastUsedACD"],[[destinations objectAtIndex:count] valueForKey:#"lastUsedCallAttempts"]);
i seen all keys without exception. All nsmanagedobject's is subclassed.
If i need implement encodeWithCored method for all subclasses, examples is appreciated.
*UPDATE for Marcus *
This is how i receive objects from server side:
- (byref NSArray*)allObjects
{
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (!coordinator) {
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
[dict setValue:#"Failed to initialize the store" forKey:NSLocalizedDescriptionKey];
[dict setValue:#"There was an error building up the data file." forKey:NSLocalizedFailureReasonErrorKey];
NSError *error = [NSError errorWithDomain:#"YOUR_ERROR_DOMAIN" code:9999 userInfo:dict];
[[NSApplication sharedApplication] presentError:error];
return nil;
}
NSManagedObjectContext *moc = [[NSManagedObjectContext alloc] init];
[moc setPersistentStoreCoordinator:coordinator];
[moc setUndoManager:nil];
NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
[nc addObserver:self
selector:#selector(mergeChangesForClient:)
name:NSManagedObjectContextDidSaveNotification
object:thirdMOC];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Carrier"
inManagedObjectContext:moc];
[request setEntity:entity];
[request setIncludesSubentities:YES];
NSError *error = nil;
NSArray *objects = [moc executeFetchRequest:request error:&error];
[request release], request = nil;
for (NSManagedObject *carrier in objects) {
NSSet *destinations = [carrier valueForKeyPath:#"destinationsListForSale"];
for (NSManagedObject *destination in destinations) [destination addObserver:self forKeyPath:#"rate" options:NSKeyValueObservingOptionNew context:nil];
}
if (error) {
NSLog(#"%#:%# error: %#", [self class], NSStringFromSelector(_cmd), error);
return nil;
}
return objects;
}
This is what i do with them on client side:
NSArray *allObjects = [server allObjects];
[carrierArrayController setContent:allObjects];
There is no serialization in this case. Any other ways (like send copy of server moc to client side doesn't work, it just generate exceptions on main.c).
p.s. many thanks to Marcus for his Core Data book.
unrecognized selector sent to class 0x1000a2ed8 2011-03-17 02:15:18.566 snowClient[19380:903] +[AppDelegate encodeWithCoder:]: unrecognized selector sent to class 0x1000a2ed8
That is not a core data problem. That is an error in your code where you are trying to call a method on an object that does not respond to that method. You need to track that down as it appears that you are trying to serialize your AppDelegate.
Update
What kind of class is 0x1000a2ed8? Break on the exception and print out the object to see what it is. Again, this is not a core data error directly, it is sending a messages to an object that does not respond to that message. It is possible that Core Data no longer allows you to send Managed objects across as distributed objects. It is possible that this is simply an issue with an over-released object. No way to know without further investigation.
Step one: Find out what object 0x1000a2ed8 is and see if the object changes from one run to the next.
I know I can set default values either in the datamodel, or in the -awakeFromInsert method of the entity class. For example, to make a "date" property default to the current date:
- (void) awakeFromInsert
{
NSDate *now = [NSDate date];
self.date = now;
}
How though can I make an "idNumber" property default to one greater than the previous object's idNumber?
Thanks, Oli
EDIT: Relevant code for my attempt (now corrected)
- (void) awakeFromInsert
{
self.idNumber = [NSNumber numberWithInt:[self maxIdNumber] + 1];
}
-(int)maxIdNumber{
NSManagedObjectContext *moc = [self managedObjectContext];
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:#"Flight" inManagedObjectContext:moc];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
[request setEntity:entityDescription];
// Set example predicate and sort orderings...
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"idNumber > %#", [NSNumber numberWithInt:0]];
[request setPredicate:predicate];
[request setFetchLimit:1];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"idNumber" ascending:NO];
[request setSortDescriptors:[NSArray arrayWithObject:sortDescriptor]];
[sortDescriptor release];
NSError *error;
NSArray *array = [moc executeFetchRequest:request error:&error];
if (array == nil | array.count == 0)
{
return 0;
}
return [[[array objectAtIndex:0] valueForKey:#"idNumber"] intValue];
}
If the maxIdNumber method is called, the new object is added to the table twice!? (but with the correct idNumber). The two entries in the table are linked - editing / removing one also edits / removes the other. For this reason I believe it has something to do with the managed object context. For what its worth, the outcome (two copies) is the same no matter how many times the maxIdNumber method is called in the awakFromNib; even if self.idNumber is just set to [NSNumber numberWithInt:5] and the maxIdNumber method is just called for a throwaway variable.
Any clues??
SOLVED IT!
Ok, the problem of double entry occurs when a fetch request is performed from within the awakeFromInsert method. Quoting from the docs:
You are typically discouraged from performing fetches within an implementation of awakeFromInsert. Although it is allowed, execution of the fetch request can trigger the sending of internal Core Data notifications which may have unwanted side-effects. For example, on Mac OS X, an instance of NSArrayController may end up inserting a new object into its content array twice.
A way to get around it is to use the perfromSelector:withObject:afterDelay method as outlined here (I am only allowed to post one hyperlink :( ):http://www.cocoabuilder.com/archive/cocoa/232606-auto-incrementing-integer-attribute-in-awakefrominsert.html.
My working code is now as follows: (note, I have put the bulk of the fetching code used above into a category to tidy it up a little, this allows me to use the method fetchObjectsForEntityName:withPredicate:withFetchLimit:withSortDescriptors:)
- (void) awakeFromInsert
{
[self performSelector:#selector(setIdNumber) withObject:nil afterDelay:0];
self.date = [NSDate date];
}
-(void)setIdNumber
{
int num = 0;
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"idNumber" ascending:NO];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"idNumber > %#", [NSNumber numberWithInt:0]];
NSArray *array = [[self managedObjectContext] fetchObjectsForEntityName:#"Flight"
withPredicate:predicate
withFetchLimit:0
withSortDescriptors:[NSArray arrayWithObject:sortDescriptor]];
[sortDescriptor release];
if (array != nil & array.count != 0)
{
num = [[[array objectAtIndex:0] valueForKey:#"idNumber"] intValue];
}
num ++;
[self setIdNumber:[NSNumber numberWithInt:num]];
}
Let me know what you think!
One Approach: Create a fetch request of all instances of your entity with a limit of 1, sorted by idNumber to get the highest number.
Another Approach: Keep the highest idNumber in your store's metadata and keep incrementing it.
There are plenty of arguments for and against either. Ultimately, those are the two most common and the choice is yours.
An easier way to do that is to override the newObject method of NSArrayController:
- (id) newObject
{
id result=[super newObject];
[result setValue: [NSDate date] forKey: #"date"];
return result;
}