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  • Does it make sense to use a NSFetchedResultsController without an UITableViewController? How are the

    - by dontWatchMyProfile
    I mean... could I also just create a plain old UIViewController and then set up a UITableView myself, plus an NSFetchedResultsController? How much do UITableViewController and NSFetchedResultsController interact with eachother? As far as I see it, UITableViewController is NOT by default already adopting the NSFetchedResultsControllerDelegate protocol. It almost looks like if UITableViewController has been developed without knowing about NSFetchedResultsController. Probably they even did that before developing FRC. Anyways, just a raw guess because the UITableViewController lacks of mentioning FRC at all. So the only thing I see in UITableViewController is that it is already the delegate for a UITableView by adopting the protocol, and it sets up the UITableView instance for me and assigns it internally to it's tableView property. Is that the whole magic of UITableViewController? (note: the nsfetchedresultscontrolle tag is not a typo. SO has a limit for the num of chars...too bad for that missing r, that's why I avoided this tag in my other buch of questions like the plague)

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  • NSFetchedResultsController crashing on performFetch: when using a cache

    - by Oliver
    I make use of NSFetchedResultsController to display a bunch of objects, which are sectioned using dates. On a fresh install, it all works perfectly and the objects are displayed in the table view. However, it seems that when the app is relaunched I get a crash. I specify a cache when initialising the NSFetchedResultsController, and when I don't it works perfectly. Here is how I create my NSFetchedResultsController: - (NSFetchedResultsController *)results { // If we are not nil, stop here if (results != nil) return results; // Create the fetch request, entity and sort descriptors NSFetchRequest *fetch = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Event" inManagedObjectContext:self.managedObjectContext]; NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"utc_start" ascending:YES]; NSArray *descriptors = [[NSArray alloc] initWithObjects:descriptor, nil]; // Set properties on the fetch [fetch setEntity:entity]; [fetch setSortDescriptors:descriptors]; // Create a fresh fetched results controller NSFetchedResultsController *fetched = [[NSFetchedResultsController alloc] initWithFetchRequest:fetch managedObjectContext:self.managedObjectContext sectionNameKeyPath:@"day" cacheName:@"Events"]; fetched.delegate = self; self.results = fetched; // Release objects and return our controller [fetched release]; [fetch release]; [descriptor release]; [descriptors release]; return results; } These are the messages I get when the app crashes: FATAL ERROR: The persistent cache of section information does not match the current configuration. You have illegally mutated the NSFetchedResultsController's fetch request, its predicate, or its sort descriptor without either disabling caching or using +deleteCacheWithName: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'FATAL ERROR: The persistent cache of section information does not match the current configuration. You have illegally mutated the NSFetchedResultsController's fetch request, its predicate, or its sort descriptor without either disabling caching or using +deleteCacheWithName:' I really have no clue as to why it's saying that, as I don't believe I'm doing anything special that would cause this. The only potential issue is the section header (day), which I construct like this when creating a new object: // Set the new format [formatter setDateFormat:@"dd MMMM"]; // Set the day of the event [event setValue:[formatter stringFromDate:[event valueForKey:@"utc_start"]] forKey:@"day"]; Like I mentioned, all of this works fine if there is no cache involved. Any help appreciated!

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  • NSFetchedResultsController fetch request - updating predicate and UITableView

    - by Macatomy
    In my iPhone Core Data app I have it configured in a master-detail view setup. The master view is a UITableView that lists objects of the List entity. The List entity has a to-many relationship with the Task entity (called "tasks"), and the Task entity has an inverse to-one relationship with List called "list". When a List object is selected in the master view, I want the detail view (another UITableView) to list the Task objects that correspond to that List object. What I've done so far is this: In the detail view controller I've declared a property for a List object: @property (nonatomic, retain) List *list; Then in the master view controller I use this table view delegate method to set the list property of the detail view controller when a list is selected: - (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { NSManagedObject *selectedObject = [[self fetchedResultsController] objectAtIndexPath:indexPath]; detailViewController.list = (List*)selectedObject; } Then, I've overriden the setter for the list property in the detail view controller like this: - (void)setList:(List*)newList { if (list != newList) { [list release]; list = [newList retain]; NSPredicate *newPredicate = [NSPredicate predicateWithFormat:@"(list == %@)", list]; [NSFetchedResultsController deleteCacheWithName:@"Root"]; [[[self fetchedResultsController] fetchRequest] setPredicate:newPredicate]; NSError *error = nil; if (![[self fetchedResultsController] performFetch:&error]) { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } } } What I'm doing here is setting a predicate on the fetched results to filter out the objects so that I only get the ones that belong to the selected List object. The fetchedResultsController getter for the detail view controller looks like this: - (NSFetchedResultsController *)fetchedResultsController { if (fetchedResultsController == nil) { NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Task" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"FALSEPREDICATE"]; [fetchRequest setPredicate:predicate]; NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [fetchRequest setSortDescriptors:sortDescriptors]; NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:@"Root"]; aFetchedResultsController.delegate = self; self.fetchedResultsController = aFetchedResultsController; [aFetchedResultsController release]; [fetchRequest release]; [sortDescriptor release]; [sortDescriptors release]; } return fetchedResultsController; } Its almost unchanged from the default in the Core Data project template, the change I made is to add a predicate that always returns false, the reason being that when there is no List selected I don't want any items to be displayed in the detail view (if a list is selected the predicate is changed in the setter for the list property). However, when I select a list item, nothing really happens. Nothing in the table view changes, it stays empty. I'm sure my logic is flawed in several places, advice is appreciated Thanks

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  • Fixing predicated NSFetchedResultsController/NSFetchRequest performance with SQLite backend?

    - by Jaanus
    I have a series of NSFetchedResultsControllers powering some table views, and their performance on device was abysmal, on the order of seconds. Since it all runs on main thread, it's blocking my app at startup, which is not great. I investigated and turns out the predicate is the problem: NSPredicate *somePredicate = [NSPredicate predicateWithFormat:@"ANY somethings == %@", something]; [fetchRequest setPredicate:somePredicate]; I.e the fetch entity, call it "things", has a many-to-many relation with entity "something". This predicate is a filter that limits the results to only things that have a relation with a particular "something". When I removed the predicate for testing, fetch time (the initial performFetch: call) dropped (for some extreme cases) from 4 seconds to around 100ms or less, which is acceptable. I am troubled by this, though, as it negates a lot of the benefit I was hoping to gain with Core Data and NSFRC, which otherwise seems like a powerful tool. So, my question is, how can I optimize this performance? Am I using the predicate wrong? Should I modify the model/schema somehow? And what other ways there are to fix this? Is this kind of degraded performance to be expected? (There are on the order of hundreds of <1KB objects.) EDIT WITH DETAILS: Here's the code: [fetchRequest setFetchLimit:200]; NSLog(@"before fetch"); BOOL success = [frc performFetch:&error]; if (!success) { NSLog(@"Fetch request error: %@", error); } NSLog(@"after fetch"); Updated logs (previously, I had some application inefficiencies degrading the performance here. These are the updated logs that should be as close to optimal as you can get under my current environment): 2010-02-05 12:45:22.138 Special Ppl[429:207] before fetch 2010-02-05 12:45:22.144 Special Ppl[429:207] CoreData: sql: SELECT DISTINCT 0, t0.Z_PK, t0.Z_OPT, <model fields> FROM ZTHING t0 LEFT OUTER JOIN Z_1THINGS t1 ON t0.Z_PK = t1.Z_2THINGS WHERE t1.Z_1SOMETHINGS = ? ORDER BY t0.ZID DESC LIMIT 200 2010-02-05 12:45:22.663 Special Ppl[429:207] CoreData: annotation: sql connection fetch time: 0.5094s 2010-02-05 12:45:22.668 Special Ppl[429:207] CoreData: annotation: total fetch execution time: 0.5240s for 198 rows. 2010-02-05 12:45:22.706 Special Ppl[429:207] after fetch If I do the same fetch without predicate (by commenting out the two lines in the beginning of the question): 2010-02-05 12:44:10.398 Special Ppl[414:207] before fetch 2010-02-05 12:44:10.405 Special Ppl[414:207] CoreData: sql: SELECT 0, t0.Z_PK, t0.Z_OPT, <model fields> FROM ZTHING t0 ORDER BY t0.ZID DESC LIMIT 200 2010-02-05 12:44:10.426 Special Ppl[414:207] CoreData: annotation: sql connection fetch time: 0.0125s 2010-02-05 12:44:10.431 Special Ppl[414:207] CoreData: annotation: total fetch execution time: 0.0262s for 200 rows. 2010-02-05 12:44:10.457 Special Ppl[414:207] after fetch 20-fold difference in times. 500ms is not that great, and there does not seem to be a way to do it in background thread or otherwise optimize that I can think of. (Apart from going to a binary store where this becomes a non-issue, so I might do that. Binary store performance is consistently ~100ms for the above 200-object predicated query.) (I nested another question here previously, which I now moved away).

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  • Core Data: Keypath "objectID" not found in entity

    - by Martin Gordon
    I'm using NSFetchedResultsController with a predicate to load a list of Documents in my application. I want to load all the Documents except the currently active one. I am using Rentzsch's MOGenerator to create a _Document class and then I put all my custom code in the Document subclass. _Document generates an objectID property with type DocumentID. In the class that creates the controller, I set the controller's currentDocID property: controller.currentDocID = self.document.objectID; In the controller itself, I lazy load the fetchedResultsController like this: - (NSFetchedResultsController *)fetchedResultsController { if (fetchedResultsController != nil) { return fetchedResultsController; } NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Document" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(objectID != %@)", self.currentDocID]; [fetchRequest setPredicate:predicate]; NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"dateModified" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [fetchRequest setSortDescriptors:sortDescriptors]; NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:@"Root"]; aFetchedResultsController.delegate = self; self.fetchedResultsController = aFetchedResultsController; [aFetchedResultsController release]; [sortDescriptor release]; [sortDescriptors release]; return fetchedResultsController; } When the fetchedResultsController loads, my app crashes with an unhandled exception: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath objectID not found in entity <NSSQLEntity Document id=1>' It's my understanding that all NSManagedObjects have an objectID, whether temporary or permanent. Is this not the case? Any thoughts?

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  • NSFetchedResultsController Crashes When Navigating from One UITableViewController to Another

    - by wgpubs
    In my core data model I have a Person entity that has a "to many" relationship a Course entity (I also have an inverse "to one" relationship from Course to Person). Now I have a subclassed UITableViewController that uses a NSFetchedResultsController to display Person objects which works fine. I have this set up so that when you click on a Person it publishes another subclassed UITableViewController that uses a NSFetchedController as well to display the Courses associated to the person. PROBLEM: I get this exception whenever I click on the Person and attempt to display the Course UITableViewController ... "Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath name not found in entity <NSSQLEntity Course id=2>'" Any ideas on how to resolve or troubleshoot? The code between the two ViewControllers is almost identical except for the NSFetchedResultsController being configured for "Person" entities in one and "Course" entities in another

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  • NSFetchedResultsController when navigating from one UITableViewController to another ...

    - by wgpubs
    In my core data model I have a Person entity that has a "to many" relationship a Course entity (I also have an inverse "to one" relationship from Course to Person). Now I have a subclassed UITableViewController that uses a NSFetchedResultsController to display Person objects which works fine. I have this set up so that when you click on a Person it publishes another subclassed UITableViewController that uses a NSFetchedController as well to display the Courses associated to the person. PROBLEM: I get this exception whenever I click on the Person and attempt to display the Course UITableViewController ... "Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath name not found in entity '" Any ideas on how to resolve or troubleshoot? The code between the two ViewControllers is almost identical except for the NSFetchedResultsController being configured for "Person" entities in one and "Course" entities in another

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  • CoreData update problems

    - by kpower
    My app makes updates in background thread then saves context changes. And in main context there is a table view that works with NSFetchedResultsController. For some time updates work correctly, but then exception is thrown. To check this I've added NSLog(@"%@", [self.controller fetchedObjects]); to -controllerDidChangeContent:. Here is what I got: "<PRBattle: 0x6d30530> (entity: PRBattle; id: 0x6d319d0 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p2> ; data: {\n battleId = \"-1\";\n finishedAt = \"2012-11-06 11:37:36 +0000\";\n opponent = \"0x6d2f730 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PROpponent/p1>\";\n opponentScore = nil;\n score = nil;\n status = 4;\n})", "<PRBattle: 0x6d306f0> (entity: PRBattle; id: 0x6d319f0 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p1> ; data: {\n battleId = \"-1\";\n finishedAt = \"2012-11-06 11:37:36 +0000\";\n opponent = \"0x6d2ddb0 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PROpponent/p3>\";\n opponentScore = nil;\n score = nil;\n status = 4;\n})", "<PRBattle: 0x6d30830> (entity: PRBattle; id: 0x6d31650 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p11> ; data: <fault>)", "<PRBattle: 0x6d306b0> (entity: PRBattle; id: 0x6d319e0 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p5> ; data: {\n battleId = 325;\n finishedAt = nil;\n opponent = \"0x6d2f730 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PROpponent/p1>\";\n opponentScore = 91;\n score = 59;\n status = 3;\n})", "<PRBattle: 0x6d30730> (entity: PRBattle; id: 0x6d31a00 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p6> ; data: {\n battleId = 323;\n finishedAt = nil;\n opponent = \"0x6d2ddb0 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PROpponent/p3>\";\n opponentScore = 0;\n score = 0;\n status = 3;\n})", "<PRBattle: 0x6d307b0> (entity: PRBattle; id: 0x6d31630 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p9> ; data: {\n battleId = 370;\n finishedAt = \"2012-11-06 14:24:14 +0000\";\n opponent = \"0x79a8e90 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PROpponent/p2>\";\n opponentScore = 180;\n score = 180;\n status = 4;\n})", "<PRBattle: 0x6d307f0> (entity: PRBattle; id: 0x6d31640 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p10> ; data: {\n battleId = 309;\n finishedAt = \"2012-11-02 01:19:27 +0000\";\n opponent = \"0x79a8e90 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PROpponent/p2>\";\n opponentScore = 120;\n score = 240;\n status = 4;\n})", "<PRBattle: 0x6d30770> (entity: PRBattle; id: 0x6d31620 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p7> ; data: {\n battleId = 315;\n finishedAt = \"2012-11-02 02:26:24 +0000\";\n opponent = \"0x79a8e90 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PROpponent/p2>\";\n opponentScore = 119;\n score = 179;\n status = 4;\n})" ) Faulted object (0xe972610) here causes crash. I've logged data during update & before saving. This object is in updatedObjects only. Why can this method return "bad" object? (Moreover, during updates this object is affected almost each update. And only after some passes becomes "bad" one). P.S.: I use RestKit to manage CoreData. UPDATED: The exception was got, when I did smth. like this: for (PRBattle *battle in [self.controller fetchedObjects) { switch (battle.statusScalar) { case ... default: [battle willAccessValueForKey:nil]; NSAssert1(NO, @"Unexpected battle status found: %@", battle); } } The exception is on line with -willAccessValueForKey:. Scalar status for battle is enum, that is bind to integer values 1..4. I've mentioned all possible values in switch's cases (above default:). And the last one has break;. So this one is possible only when battle.statusScalar returns non-enum value. Status scalar implementation in PRBattle: - (PRBattleStatuses)statusScalar { [self willAccessValueForKey:@"statusScalar"]; PRBattleStatuses result = (PRBattleStatuses)[self.status integerValue]; [self didAccessValueForKey:@"statusScalar"]; return result; } And battle.status has validation rules: - min-value: 1 - max-value: 4 - default: no value And the last thing - debug log: objc[4664]: EXCEPTIONS: throwing 0x7d33f80 (object 0xe67d2a0, a _NSCoreDataException) objc[4664]: EXCEPTIONS: searching through frame [ip=0x97b401 sp=0xbfffd9b0] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: catch(id) objc[4664]: EXCEPTIONS: unwinding through frame [ip=0x97b401 sp=0xbfffd9b0] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: handling exception 0x7d33f60 at 0x97b79f objc[4664]: EXCEPTIONS: rethrowing current exception objc[4664]: EXCEPTIONS: searching through frame [ip=0x97b911 sp=0xbfffd9b0] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: searching through frame [ip=0x9ac8b7 sp=0xbfffdc20] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: searching through frame [ip=0x97ee80 sp=0xbfffdc40] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: searching through frame [ip=0x361d0 sp=0xbfffdc70] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: searching through frame [ip=0xa701d8 sp=0xbfffde10] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: catch(id) objc[4664]: EXCEPTIONS: unwinding through frame [ip=0x97b911 sp=0xbfffd9b0] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: finishing handler objc[4664]: EXCEPTIONS: searching through frame [ip=0x97b963 sp=0xbfffd9b0] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: searching through frame [ip=0x9ac8b7 sp=0xbfffdc20] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: searching through frame [ip=0x97ee80 sp=0xbfffdc40] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: searching through frame [ip=0x361d0 sp=0xbfffdc70] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: searching through frame [ip=0xa701d8 sp=0xbfffde10] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: catch(id) objc[4664]: EXCEPTIONS: unwinding through frame [ip=0x97b963 sp=0xbfffd9b0] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: unwinding through frame [ip=0x9ac8b7 sp=0xbfffdc20] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: unwinding through frame [ip=0x97ee80 sp=0xbfffdc40] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: unwinding through frame [ip=0x361d0 sp=0xbfffdc70] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: unwinding through frame [ip=0x3656f sp=0xbfffdc70] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: unwinding through frame [ip=0xa701d8 sp=0xbfffde10] for exception 0x7d33f60 objc[4664]: EXCEPTIONS: handling exception 0x7d33f60 at 0xa701f5 2012-11-07 13:37:55.463 TestApp[4664:fb03] CoreData: error: Serious application error. An exception was caught from the delegate of NSFetchedResultsController during a call to -controllerDidChangeContent:. CoreData could not fulfill a fault for '0x6d31650 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p10>' with userInfo { NSAffectedObjectsErrorKey = ( "<PRBattle: 0x6d30830> (entity: PRBattle; id: 0x6d31650 <x-coredata://882BD521-90CD-4682-B19A-000A4976E471/PRBattle/p10> ; data: <fault>)" ); }

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  • NSFetchedResultsController not updating UITableView's section indexes

    - by Luther Baker
    I am populating a UITableViewController with an NSFetchedResultsController with results creating sections that populate section headers and a section index. I am using the following method to populate the section index: - (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView { return [fetchedResultsController_ sectionIndexTitles]; } and now I've run into a problem. When I add a new element to the NSManagedObjectContext associated with the NSFetchedResultsController, the new element is saved and appropriately displayed as a cell in the UITableView ... except for one thing. If the new element creates a new SECTION, the new section index does not show up in the right hand margin unless I pop the UINavigationController's stack and reload the UITableViewController. I have conformed to the NSFetchedResultsControllerDelegate's interface and manually invoke [self.tableView reloadSectionIndexTitles]; at the end of both these delegate methods: controller:didChangeSection... controller:didChangeObject... and while I can debug and trace the execution into the methods and see the reload call invoked, the UITableView's section index never reflects the section changes. Again, the data shows up - new sections are physically visible (or removed) in the UITableView but the section indexes are not updated. Am I missing something?

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  • NSFetchedResultsController - Delegate methods crashing under iPhone OS 3.0, but NOT UNDER 3.1

    - by Scott Langendyk
    Hey guys, so I've got my NSFetchedResultsController working fine under the 3.1 SDK, however I start getting some weird errors, specifically in the delegate methods when I try it under 3.0. I've determined that this is related to the NSFetchedResultsControllerDelegate methods. This is what I have set up. The inEditingMode stuff has to do with the way I've implemented adding another static section to the table. - (void)controllerWillChangeContent:(NSFetchedResultsController*)controller { [self.tableView beginUpdates]; } - (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type{ NSIndexSet *sectionSet = [NSIndexSet indexSetWithIndex:sectionIndex]; if(self.inEditingMode){ sectionSet = [NSIndexSet indexSetWithIndex:sectionIndex + 1]; } switch (type) { case NSFetchedResultsChangeInsert: [self.tableView insertSections:sectionSet withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [self.tableView deleteSections:sectionSet withRowAnimation:UITableViewRowAnimationFade]; break; default: [self.tableView reloadData]; break; } } - (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath{ NSIndexPath *relativeIndexPath = indexPath; NSIndexPath *relativeNewIndexPath = newIndexPath; if(self.inEditingMode){ relativeIndexPath = [NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section + 1]; relativeNewIndexPath = [NSIndexPath indexPathForRow:newIndexPath.row inSection:newIndexPath.section + 1]; } switch(type) { case NSFetchedResultsChangeInsert: [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:relativeNewIndexPath] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:relativeIndexPath] withRowAnimation:UITableViewRowAnimationFade]; break; default: [self.tableView reloadData]; break; } } -(void)controllerDidChangeContent:(NSFetchedResultsController *)controller{ [self.tableView endUpdates]; } When I add an entity to the managed object context, I get the following error: Serious application error. Exception was caught during Core Data change processing: *** -[NSCFArray objectAtIndex:]: index (1) beyond bounds (1) with userInfo (null) I put a breakpoint on objc_exception_throw, and the crash seems to be occuring inside of controllerDidChangeContent. If I comment out all of the self.tableView methods, and put a single [self.tableView reloadData] inside of controllerDidChangeContent, everything works as expected. Anybody have any idea as to why this is happening?

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  • iPhone contacts app styled indexed table view implementation

    - by KSH
    My Requirement: I have this straight forward requirement of listing names of people in alphabetical order in a Indexed table view with index titles being the starting letter of alphabets (additionally a search icon at the top and # to display misc values which start with a number and other special characters). What I have done so far: 1. I am using core data for storage and "last_name" is modelled as a String property in the Contacts entity 2.I am using a NSFetchedResultsController to display the sorted indexed table view. Issues accomplishing my requirement: 1. First up, I couldn't get the section index titles to be the first letter of alphabets. Dave's suggestion in the following post, helped me achieve the same: http://stackoverflow.com/questions/1112521/nsfetchedresultscontroller-with-sections-created-by-first-letter-of-a-string The only issue I encountered with Dave' suggestion is that I couldn't get the misc named grouped under "#" index. What I have tried: 1. I tried adding a custom compare method to NSString (category) to check how the comparison and section is made but that custom method doesn't get called when specified in the NSSortDescriptor selector. Here is some code: `@interface NSString (SortString) -(NSComparisonResult) customCompare: (NSString*) aStirng; @end @implementation NSString (SortString) -(NSComparisonResult) customCompare:(NSString *)aString { NSLog(@"Custom compare called to compare : %@ and %@",self,aString); return [self caseInsensitiveCompare:aString]; } @end` Code to fetch data: `NSArray *sortDescriptors = [NSArray arrayWithObject:[[[NSSortDescriptor alloc] initWithKey:@"last_name" ascending:YES selector:@selector(customCompare:)] autorelease]]; [fetchRequest setSortDescriptors:sortDescriptors]; fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:@"lastNameInitial" cacheName:@"MyCache"];` Can you let me know what I am missing and how the requirement can be accomplished ?

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  • Serious Application Error

    - by Garry
    I have a TableView controller class that uses a fetched results controller to display a list of 'patient' entities taken from a Core Data model. The sections of this table are taken from a patient attribute called 'location'. Here is the sort descriptor for the fetch request: NSSortDescriptor *locationDescriptor = [[NSSortDescriptor alloc] initWithKey:@"location" ascending:YES]; NSSortDescriptor *lastNameDescriptor = [[NSSortDescriptor alloc] initWithKey:@"lastName" ascending:YES]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:locationDescriptor, lastNameDescriptor, nil]; Here is the initialisation code for the FRC: NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:@"location" cacheName:@"List"]; When I want to add a new 'patient' entity - I click an add button which then pushes an 'add new patient' view controller to the navigation stack. The first patient I add works fine. If I add a second patient - the app will sometimes crash with the following error: 2010-03-22 14:42:05.270 Patients[1126:207] Serious application error. Exception was caught during Core Data change processing: * -[NSCFArray insertObject:atIndex:]: index (1) beyond bounds (1) with userInfo (null) 2010-03-22 14:42:05.272 Patients[1126:207] Terminating app due to uncaught exception 'NSRangeException', reason: '** -[NSCFArray insertObject:atIndex:]: index (1) beyond bounds (1)' This only seems to happen if the patient's have a location added (if none is added then the location defaults to 'unknown'). It seems to have something to do with the sorting of the location too. For instance, if the first patient location = ward 14 and the second = ward 9 then it crashes without fail. I'm wondering if this is something to do with how I am asking the fetched results controller to sort the section names?? This bug is driving me nuts and I just can't figure it out. Any help would be greatly appreciated!

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  • NSFetchedResultsController titleForHeaderInSection with formatted NSDate

    - by Daniel Granger
    In my Core Data app I am using a FetchedResultsController. Usually to set titles for headers in a UITableView you would implement the following method like so: - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { id <NSFetchedResultsSectionInfo> sectionInfo = [[<#Fetched results controller#> sections] objectAtIndex:section]; return [sectionInfo name]; } where [sectionInfo name] returns a NSString. my sectionKeyPath is based on an NSDate and this all works fine apart from the section headers it gives me are the raw date description strings (e.g. 12/12/2009 12:32:32 +0100) which look a bit of a mess in a header! So I want to use a date formatter on this to make a nice header like "Apr 17 2010" but I can't do that with the [sectionInfo name] as this is NSString! Any Ideas? Many Thanks

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  • How can I sort by a transformable attribute in an NSFetchedResultsController?

    - by Mike Laurence
    I'm using NSValueTransformers to encrypt attributes (strings, dates, etc.) in my Core Data model, but I'm pretty sure it's interfering with the sorting in my NSFetchedResultsController. Does anyone know if there's a way to get around this? I suppose it depends on how the sort is performed; if it's always only performed directly on the database, then I'm probably out of luck. If it sorts on the objects themselves, then perhaps there's a way to activate the transformation before the sort occurs. I'm guessing it's directly on the database, though, since the sort would be key in grabbing subsets of the collection, which is the main benefit of NSFetchedResultsController anyway.

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  • Sorting by dates (including nil) with NSFetchedResultsController

    - by glorifiedHacker
    In my NSFetchedResultsController, I set a sortDescriptor that sorts based on the date property of my managed objects. The problem that I have encountered (along with several others according to Google) is that nil values are sorted at the earliest end rather than the latest end of the date spectrum. I want my list to be sorted earliest, earlier, now, later, latest, nil. As I understand it, this sorting is done at the database level in SQLite and so I cannot construct my own compare: method to provide the sorting I want. I don't want to manually sort in memory, because I would have to give up all of the benefits of NSFetchedResultsController. I can't do compound sorting because the sectionNameKeyPaths are tightly coupled to the date ranges. I could write a routine that redirects indexPath requests so that section 0 in the results controller gets mapped to the last section of the tableView, but I fear that would add a lot of overhead, severely increase the complexity of my code, and be very, very error-prone. The latest idea that I am considering is to map all nil dates to the furthest future date that NSDate supports. My left brain hates this idea, as it feels more like a hack. It will also take a bit of work to implement, since checking for nil factors heavily into how I process dates in my app. I don't want to go this route without first checking for better options. Can anyone think of a better way to get around this problem?

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  • NSFetchedResultsController secondary sorting not working?

    - by binkly
    Hello, I'm using NSFetchedResultsController to fetch Message entities with Core Data. I want my tableview to group the messages by an attribute called ownerName. This works fine in the sense that I get a proper UI dispalying appropriately named sections. I can achieve this with the code below: NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"ownerName" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [fetchRequest setSortDescriptors:sortDescriptors]; NSFetchedResultsController *fetchedResultsController = nil; fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:[appDelegate managedObjectContext] sectionNameKeyPath:@"ownerName" cacheName:@"Messages"] What'd I'd like to do now is have the section with the newest message at the top; exactly how it works with the Messages app on iPhone currently. I've tried adding a second sort descriptor and putting it in an array of sort descriptors and passing that to the fetchRequest but it doesn't appear to be affecting anything. Here is the 2nd sort descriptor that I used. NSSortDescriptor *idDescriptor = [[NSSortDescriptor alloc] initWithKey:@"createdAt" ascending:YES]; If anyone could provide some insight into this I would greatly appreciate it.

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  • NSPredicate acting strange in NSFetchedResultsController

    - by Scott Langendyk
    I feel as if this should be very simple, but it's behaving strangely. I have 3 entities, with a relationship as such Entity A <-- Entity B <<-- Entity C I have an NSFetchedResults controller and I'm trying to filter the results of Entity A using the following predicate. [NSPredicate predicateWithFormat:@"NONE entityB.entityC == %@", self.entityC]; When I try and run the app, the output shows no results. I can alter the predicate slightly to: [NSPredicate predicateWithFormat:@"ANY entityB.entityC == %@", self.entityC]; And it shows me only the results that I want it to filter out. Why is this happening?

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  • Appending data to NSFetchedResultsController during find or create loop

    - by Justin Williams
    I have a table view that is managed by an NSFetchedResultsController. I am having an issue with a find-or-create operation, however. When the user hits the bottom of my table view, I am querying my server for another batch of content. If it doesn't exist in the local cache, we create it and store it. If it does exist, however, I want to append that data to the fetched results controller and display it. I can't quite figure that part out. Here's what I'm doing thus far: Passing the returned array of values from my server to an NSOperation to process. In the operation, create a new managed object context to work with. In the operation, I iterate through the array and execute a fetch request to see if the object exists (based on its server id). If the object doesn't exist, we create it and insert it into the operations' managed object context. After the iteration completes, we save the managed object context, which triggers a merge notification on my main thread. At this point, any objects that weren't locally cached in my Core Data store before will appear, but the ones that previously existed do not come along for the ride. I feel like it's something simple I'm missing, and could use a nudge in the right direction.

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  • setIncludesSubentities: in an NSFetchRequest is broken for entities across multiple persistent store

    - by SG
    Prior art which doesn't quite address this: http://stackoverflow.com/questions/1774359/core-data-migration-error-message-model-does-not-contain-configuration-xyz I have narrowed this down to a specific issue. It takes a minute to set up, though; please bear with me. The gist of the issue is that a persistentStoreCoordinator (apparently) cannot preserve the part of an object graph where a managedObject is marked as a subentity of another when they are stored in different files. Here goes... 1) I have 2 xcdatamodel files, each containing a single entity. In runtime, when the managed object model is constructed, I manually define one entity as subentity of another using setSubentities:. This is because defining subentities across multiple files in the editor is not supported yet. I then return the complete model with modelByMergingModels. //Works! [mainEntity setSubentities:canvasEntities]; NSLog(@"confirm %@ is super for %@", [[[canvasEntities lastObject] superentity] name], [[canvasEntities lastObject] name]); //Output: "confirm Note is super for Browser" 2) I have modified the persistentStoreCoordinator method so that it sets a different store for each entity. Technically, it uses configurations, and each entity has one and only one configuration defined. //Also works! for ( NSString *configName in [[HACanvasPluginManager shared].registeredCanvasTypes valueForKey:@"viewControllerClassName"] ) { storeUrl = [NSURL fileURLWithPath:[[self applicationDocumentsDirectory] stringByAppendingPathComponent:[configName stringByAppendingPathExtension:@"sqlite"]]]; //NSLog(@"entities for configuration '%@': %@", configName, [[[self managedObjectModel] entitiesForConfiguration:configName] valueForKey:@"name"]); //Output: "entities for configuration 'HATextCanvasController': (Note)" //Output: "entities for configuration 'HAWebCanvasController': (Browser)" if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:configName URL:storeUrl options:options error:&error]) //etc 3) I have a fetchRequest set for the parent entity, with setIncludesSubentities: and setAffectedStores: just to be sure we get both 1) and 2) covered. When inserting objects of either entity, they both are added to the context and they both are fetched by the fetchedResultsController and displayed in the tableView as expected. // Create the fetch request for the entity. NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; [fetchRequest setEntity:entity]; [fetchRequest setIncludesSubentities:YES]; //NECESSARY to fetch all canvas types [fetchRequest setSortDescriptors:sortDescriptors]; [fetchRequest setFetchBatchSize:20]; // Set the batch size to a suitable number. [fetchRequest setAffectedStores:[[managedObjectContext persistentStoreCoordinator] persistentStores]]; [fetchRequest setReturnsObjectsAsFaults:NO]; Here is where it starts misbehaving: after closing and relaunching the app, ONLY THE PARENT ENTITY is fetched. If I change the entity of the request using setEntity: to the entity for 'Note', all notes are fetched. If I change it to the entity for 'Browser', all the browsers are fetched. Let me reiterate that during the run in which an object is first inserted into the context, it will appear in the list. It is only after save and relaunch that a fetch request fails to traverse the hierarchy. Therefore, I can only conclude that it is the storage of the inheritance that is the problem. Let's recap why: - Both entities can be created, inserted into the context, and viewed, so the model is working - Both entities can be fetched with a single request, so the inheritance is working - I can confirm that the files are being stored separately and objects are going into their appropriate stores, so saving is working - Launching the app with either entity set for the request works, so retrieval from the store is working - This also means that traversing different stores with the request is working - By using a single store instead of multiple, the problem goes away completely, so creating, storing, fetching, viewing etc is working correctly. This leaves only one culprit (to my mind): the inheritance I'm setting with setSubentities: is effective only for objects creating during the session. Either objects/entities are being stored stripped of the inheritance info, or entity inheritance as defined programmatically only applies to new instances, or both. Either of these is unacceptable. Either it's a bug or I am way, way off course. I have been at this every which way for two days; any insight is greatly appreciated. The current workaround - just using a single store - works completely, except it won't be future-proof in the event that I remove one of the models from the app etc. It also boggles the mind because I can't see why you would have all this infrastructure for storing across multiple stores and for setting affected stores in fetch requests if it by core definition (of setSubentities:) doesn't work.

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  • NSFetchedResultsController: using of NSManagedObjectContext during update brings to crash

    - by Kentzo
    Here is the interface of my controller class: @interface ProjectListViewController : UITableViewController <NSFetchedResultsControllerDelegate> { NSFetchedResultsController *fetchedResultsController; NSManagedObjectContext *managedObjectContext; } @end I use following code to init fetchedResultsController: if (fetchedResultsController != nil) { return fetchedResultsController; } // Create and configure a fetch request with the Project entity. NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Project" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; // Create the sort descriptors array. NSSortDescriptor *projectIdDescriptor = [[NSSortDescriptor alloc] initWithKey:@"projectId" ascending:YES]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:projectIdDescriptor, nil]; [fetchRequest setSortDescriptors:sortDescriptors]; // Create and initialize the fetch results controller. NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:nil]; self.fetchedResultsController = aFetchedResultsController; fetchedResultsController.delegate = self; As you can see, I am using the same managedObjectContext as defined in my controller class Here is an adoption of the NSFetchedResultsControllerDelegate protocol: - (void)controllerWillChangeContent:(NSFetchedResultsController *)controller { // The fetch controller is about to start sending change notifications, so prepare the table view for updates. [self.tableView beginUpdates]; } - (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath { UITableView *tableView = self.tableView; switch(type) { case NSFetchedResultsChangeInsert: [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeUpdate: [self _configureCell:(TDBadgedCell *)[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath]; break; case NSFetchedResultsChangeMove: if (newIndexPath != nil) { [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; } else { [tableView reloadSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationFade]; } break; } } - (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type { switch(type) { case NSFetchedResultsChangeInsert: [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade]; break; } } - (void)controllerDidChangeContent:(NSFetchedResultsController *)controller { [self.tableView endUpdates]; } Inside of the _configureCell:atIndexPath: method I have following code: NSFetchRequest *issuesNumberRequest = [NSFetchRequest new]; NSEntityDescription *issueEntity = [NSEntityDescription entityForName:@"Issue" inManagedObjectContext:managedObjectContext]; [issuesNumberRequest setEntity:issueEntity]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"projectId == %@", project.projectId]; [issuesNumberRequest setPredicate:predicate]; NSUInteger issuesNumber = [managedObjectContext countForFetchRequest:issuesNumberRequest error:nil]; [issuesNumberRequest release]; I am using the managedObjectContext again. But when I am trying to insert new Project, app crashes with following exception: Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-984.38/UITableView.m:774 Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (4) must be equal to the number of rows contained in that section before the update (4), plus or minus the number of rows inserted or deleted from that section (1 inserted, 0 deleted).' Fortunately, I've found a workaround: if I create and use separate NSManagedObjectContext inside of the _configureCell:atIndexPath: method app won't crash! I only want to know, is this behavior correct or not?

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  • Core Data (NSFetchedResultsController) displaying one row per section

    - by Urizen
    I have a CoreData application which uses NSFetchedResultsController. NSFetchedResultsController is useful in that it allows me to access the fetched objects more easily etc. but I find that I have problems with the following: I get a crash when I display a single row for each section (irrespective of the number of actual rows present) as a summary of the information in that section (e.g. showing a statistical analysis of the data contained in the fetched rows for that section). I understand that the NSFetchedResultsControllerDelegatemethods have to agree with the number of rows reported per section by the UITableView Delegate method but I would like to be able to fetch all of the records for each section without necessarily displaying each of the rows. The above causes me inconsistency crashes, when I try to insert or delete data for a section, which reports that the number of rows for each section is not as it should be given the number of insertions/deletions. Is there any way I can do what I'm trying to achieve? Thanks for any help.

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  • NSFetchedResultsController: changing predicate not working?

    - by icerelic
    Hi, I'm writing an app with two tables on one screen. The left table is a list of folders and the right table shows a list of files. When tapped on a row on the left, the right table will display the files belonging to that folder. I'm using Core Data for storage. When the selection of folder changes, the fetch predicate of the right table's NSFetchedResultsController will change and perform a new fetch, then reload the table data. I used the following code snippet: NSPredicate *predicate = [NSPredicate predicateWithFormat:@"list = %@",self.list]; [fetchedResultsController.fetchRequest setPredicate:predicate]; NSError *error = nil; if (![[self fetchedResultsController] performFetch:&error]) { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } [table reloadData]; However the fetch results are still the same. I've NSLog'ed "predicate" before and after the fetch, and they were correct with updated information. The fetch results stay the same as initial fetch (when view is loaded). I'm not very familiar with the way Core Data fetches objects (is there a caching system?), but I've done similar things before(changing predicates, re-fetching data, and refreshing table) with single table views and everything went well. If someone could gave me a hint I would be very appreciated. Thanks in advance.

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  • NSFetchedResultsController is driving me crazy

    - by user267980
    Hi everyone. i've been building an app since 1 month using NSFetchedResultsController and i was testing the app on the 3.1.2 SDK. The poblem is that i've been using NSFetchedResultsController everywhere in my app and was working on the 3.1.2 version of the SDK, now my client say that i should make it compatible with the 3.0 version and the deadline is almost there. But is crashing everytime i change an object handled by the contoller, the application is crashing with very weird errors. The problem occure when removing the last object in a section and when a change make an object love to another section. I've been using a sample code from "More iPhone 3 Development Tackling iPhone SDK 3" by Dave Mark and Jeff LaMarche. I've also included some changes from link text Here is a sample output of the console when the application is crashing. * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of sections. The number of sections contained in the table view after the update (1) must be equal to the number of sections contained in the table view before the update (2), plus or minus the number of sections inserted or deleted (2 inserted, 0 deleted).' 2010-03-14 16:23:29.758 Instaproofs[5879:207] Stack: ( 807902715, 7364425, 807986683, 811271572, 815059090, 815007323, 211023, 4363331, 810589786, 807635429, 810579728, 3620573, 3620227, 3614682, 3609719, 27337, 810595174, 807686849, 807683624, 839142449, 839142646, 814752238 ) If i knew that NSFetchedResultsController is so buggy, i would never used it. So basicaly i need the my NSFetchedResultsControllerDelegate to work fine on the 3.0 and above SDKs. It would be life saver if someone help me figure out what i'm doing wrong.

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  • How to deal with many to many relationships with NSFetchedResultsController?

    - by Phil Yates
    OK so I have two entities in my data model (let's say entityA and entityB), both of these entities have a to-many relationship to each other. I have setup a NSFetchedResultsController to fetch a bunch of entityA. Now I'm trying to have the section names for the tableview be the title of entityB. sectionNameKeyPath:@"entityB.title" Now this causes a problem, where by the section name returned from that relationship appears to be ({title1}) or ({title1,title2...titleN}) obviously depending on how many different entityB's are involved. This doesn't look great in a tableview and doesn't group the objects as I would like. What I would like is a section per entityB title with entityA appearing under each section, under multiple sections if necessary. I'm at a loss as how I am supposed to achieve this whether I need to update the predicate to get the entity to appear multiple times or whether I need to update the section and header functions to do some processing as the controller loops through the objects. Any help is appreciated :) Thanks

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  • UICollectionView with one static cell and N dynamic ones from a fetchresultscontroller exception

    - by nflacco
    I'm trying to make a UITableView that shows a blog post and comments for that post. My setup is a tableview in storyboard with two dynamic prototype cells. The first cell is for the post and should never change. The second cell represents the 0 to N comments. My cellForRowAtIndexPath method shows the post cell properly, but fails to get the comment at the given index path (though if I comment out the fetch I get the appropriate number of comment cells with a green background that I set as a visual debug thing). let comment = fetchedResultController.objectAtIndexPath(indexPath) as Comment I get the following exception on this line: 2014-08-24 15:06:40.712 MessagePosting[21767:3266409] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]' *** First throw call stack: ( 0 CoreFoundation 0x0000000101aa43e5 __exceptionPreprocess + 165 1 libobjc.A.dylib 0x00000001037f9967 objc_exception_throw + 45 2 CoreFoundation 0x000000010198f4c3 -[__NSArrayM objectAtIndex:] + 227 3 CoreData 0x00000001016e4792 -[NSFetchedResultsController objectAtIndexPath:] + 162 Section and cell setup: override func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int { // #warning Incomplete method implementation. // Return the number of rows in the section. switch section { case 0: return 1 default: if let realPost:Post = post { return fetchedResultController.sections[0].numberOfObjects } else { return 0 } } } override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! { switch indexPath.section { case 0: let cell = tableView.dequeueReusableCellWithIdentifier(postViewCellIdentifier, forIndexPath: indexPath) as UITableViewCell cell.backgroundColor = lightGrey if let realPost:Post = self.post { cell.textLabel.text = realPost.text } return cell default: let cell = tableView.dequeueReusableCellWithIdentifier(commentCellIdentifier, forIndexPath: indexPath) as UITableViewCell cell.backgroundColor = UIColor.greenColor() let comment = fetchedResultController.objectAtIndexPath(indexPath) as Comment // <---------------------------- :( cell.textLabel.text = comment.text return cell } } FRC: func controllerDidChangeContent(controller: NSFetchedResultsController!) { tableView.reloadData() } func getFetchedResultController() -> NSFetchedResultsController { fetchedResultController = NSFetchedResultsController(fetchRequest: taskFetchRequest(), managedObjectContext: managedObjectContext, sectionNameKeyPath: nil, cacheName: nil) return fetchedResultController } func taskFetchRequest() -> NSFetchRequest { if let realPost:Post = self.post { let fetchRequest = NSFetchRequest(entityName: "Comment") let sortDescriptor = NSSortDescriptor(key: "date", ascending: false) fetchRequest.predicate = NSPredicate(format: "post = %@", realPost) fetchRequest.sortDescriptors = [sortDescriptor] return fetchRequest } else { return NSFetchRequest(entityName: "") } }

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