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View Full Version : CoreData and NSManagedObjectModel error




macster84
Oct 30, 2009, 04:27 PM
This error occurs in one of my ViewControllers: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '+entityForName: could not locate an NSManagedObjectModel for entity name……

I’ve compared my code to Apple’s CoreData Tutorial (Locations app) and this is the difference: the tutorial only uses an AppDelegate and RootViewController, while my app uses an AppDelegate, RootViewController, and several other ViewControllers that the user selects from the RootViewController’s view. And so I've attempted to pass the ManagedObjectContext from the RootViewController to the next ViewController.

What else needs to happen to get the ManagedObjectModel to be recognized? The .xcdatamodel file is in Xcode’s Resources folder and the entity names seem to match. Code for the ManagedObjectContext is in the .h and .m files (AppDelegate, RootViewController, and the next ViewController), but do I need more code for the ManagedObjectModel in those files too?

Apple's CoreData docs for this error says “Be sure that the model is included in your application resources and that the corresponding "project target" option in Xcode is selected.” What and where is project target option? I'm fairly new at this. Thanks in advance. :)



tiltem
Oct 18, 2010, 04:51 PM
Did you ever find the cause of this. I am having a very similar issue. Using the navigation based template with core data, and added another viewController. When returning from the new viewController to rootController receive the error when attempting to add data collected from the new view. Error is:

'NSInternalInconsistencyException', reason: '+entityForName: could not locate an NSManagedObjectModel for entity name 'Event''

ppilone
Oct 19, 2010, 10:49 AM
I would try putting a break point at the line that is causing the error. Make sure that the managed object context you're using for the NSEntityDescription is not nil.

tiltem
Oct 19, 2010, 11:50 AM
Hello and thank you for the help.
The manganedObjectContext is null during the last line of this within the insertNewObject method, but I cannot figure out why:

NSManagedObjectContext *context = [fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[fetchedResultsController fetchRequest] entity];
NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];



It works fine if I call this method upon load, but if it is called after returning from another view I added i receive the error:

'NSInternalInconsistencyException', reason: '+entityForName: could not locate an NSManagedObjectModel for entity name 'Event''

Here is my RootViewController.m:

#import "RootViewController.h"
#import "newEventController.h"
#import "Event.h"
#import "DaysSinceAppDelegate.h"


@interface RootViewController ()
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
@end


@implementation RootViewController

@synthesize fetchedResultsController, managedObjectContext;
@synthesize eventName, eventDate;

#pragma mark -
#pragma mark View lifecycle

- (void)viewDidLoad {
[super viewDidLoad];
if (self.managedObjectContext == nil) {
printf("INSIDE IF STATEM#N#T# ");
self.managedObjectContext = [(DaysSinceAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
}

self.title = @"Days Since";

// Set up the edit and add buttons.
self.navigationItem.leftBarButtonItem = self.editButtonItem;

UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addEvent)];
self.navigationItem.rightBarButtonItem = addButton;
[addButton release];

NSError *error = nil;


if (![[self fetchedResultsController] performFetch:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}

}


- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {

NSManagedObject *managedObject = [fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [NSString stringWithFormat:@"%@ - %@",
[[managedObject valueForKey:@"name"] description],
[[managedObject valueForKey:@"timeStamp"] description]];
}


#pragma mark -
#pragma mark Add a new object

-(void)addEvent{
newEventController *newEvent = [[newEventController alloc] init];
newEvent.title = @"Add Event";
[self.navigationController pushViewController:newEvent animated:YES];
[newEvent release];
}


- (void)insertNewObject {

// Create a new instance of the entity managed by the fetched results controller.
if (self.managedObjectContext == nil) {
self.managedObjectContext = [(DaysSinceAppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
}
NSManagedObjectContext *context = [fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[fetchedResultsController fetchRequest] entity];
NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:@"Event" inManagedObjectContext:context];
// If appropriate, configure the new managed object.
[newManagedObject setValue:self.eventName forKey:@"name"];
[newManagedObject setValue:self.eventDate forKey:@"timeStamp"];

// Save the context.
NSError *error = nil;
if (![context save:&error]) {
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}


-(void)addEventName:(NSString *)eName eventDate:(NSDate *) eDate{
self.eventDate = eDate;
self.eventName = eName;
printf("Here");
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:[NSString stringWithFormat:@"%@", self.eventName] message:[NSString stringWithFormat:@"Event Added"] delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release];
[self insertNewObject];

}

#pragma mark -
#pragma mark Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return [[fetchedResultsController sections] count];
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}


// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

// Configure the cell.
[self configureCell:cell atIndexPath:indexPath];

return cell;
}


// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {

if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the managed object for the given index path
NSManagedObjectContext *context = [fetchedResultsController managedObjectContext];
[context deleteObject:[fetchedResultsController objectAtIndexPath:indexPath]];

// Save the context.
NSError *error = nil;
if (![context save:&error]) {

NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
}


- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
// The table view should not be re-orderable.
return NO;
}


#pragma mark -
#pragma mark Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Navigation logic may go here -- for example, create and push another view controller.
/*
<#DetailViewController#> *detailViewController = [[<#DetailViewController#> alloc] initWithNibName:@"<#Nib name#>" bundle:nil];
NSManagedObject *selectedObject = [[self fetchedResultsController] objectAtIndexPath:indexPath];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
*/
}




#pragma mark -
#pragma mark Fetched results controller

- (NSFetchedResultsController *)fetchedResultsController {

if (fetchedResultsController != nil) {
return fetchedResultsController;
}

/*
Set up the fetched results controller.
*/
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Event" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];

// Set the batch size to a suitable number
[fetchRequest setFetchBatchSize:20];

// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"timeStamp" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

[fetchRequest setSortDescriptors:sortDescriptors];

// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
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];

return fetchedResultsController;
}


#pragma mark -
#pragma mark Fetched results controller delegate


- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
[self.tableView beginUpdates];
}


- (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)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:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;

case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}


- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
[self.tableView endUpdates];
}


#pragma mark -
#pragma mark Memory management

- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];

// Relinquish ownership any cached data, images, etc that aren't in use.
}


- (void)viewDidUnload {
// Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
// For example: self.myOutlet = nil;
}


- (void)dealloc {
[fetchedResultsController release];
[managedObjectContext release];
[super dealloc];
}
@end

tiltem
Oct 21, 2010, 12:20 AM
OK fixed the problem. I am still not exactly sure why, but maybe something to do with the fetchController. I wrote a new insert method that created a new entity and added it to the managed object context without the use of the fetchedResultsController and it works.