Question

Im pretty new to Core Data programming and Cocoa in general, so no wonder I’m having troubles 🙂

So here is my managedObjectModel method:

- (NSManagedObjectModel *)managedObjectModel
{
    if (managedObjectModel != nil)
    {
        return managedObjectModel;
    }
    NSString *modelPath = [[NSBundle mainBundle] pathForResource:@"Model" ofType:@"momd"];
    NSURL *modelURL = [NSURL fileURLWithPath:modelPath];

    NSAssert(modelURL != nil,@"modelURL == nil");
    managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
    return managedObjectModel;
}

Here is the part of the code that crashes:

NSManagedObjectModel *mom = [self managedObjectModel];

managedObjectModel = mom;

if (applicationLogDirectory() == nil)
{
    NSLog(@"Could not find application logs directory\nExiting...");
    exit(1);
}

NSManagedObjectContext *moc = [self managedObjectContext];
NSProcessInfo *processInfo = [NSProcessInfo processInfo];

NSEntityDescription *newShotEntity = [[mom entitiesByName] objectForKey:@"Entity"];

Entity *shEnt = [[Entity alloc] initWithEntity:newShotEntity insertIntoManagedObjectContext:moc];


shEnt.pid = [processInfo processIdentifier]; // EXC_BAD_ACCESS (code=1, address=0x28ae) here !!!

NSError *error;

if (![moc save: &error])
{
   NSLog(@"Error while saving\n%@",
        ([error localizedDescription] != nil) ? [error localizedDescription] : @"Unknown Error");
        exit(1);
}

Im really confused why I’m having this error, since when I hardcoded the Data Model instead of using .xcdatamodeld file it was working just fine!

Any kind of help is really appreciated!

EDIT 1: since I’m having all those questions asked I want to make everything clear, sorry for not providing all this before.

    // Entity.h

    #import <CoreData/CoreData.h>

    @interface Entity : NSManagedObject

    @property (strong) NSDate *date;
    @property (assign) NSInteger pid;

    @end

   //Entity.m

   #import "Entity.h"

   @interface Entity ()
   @property (strong) NSDate *primitiveDate;
   @end

   @implementation Entity

  @dynamic date,primitiveDate,pid;


  - (void) awakeFromInsert
  {
    [super awakeFromInsert];
    self.primitiveDate = [NSDate date];
  }


  - (void)setNilValueForKey:(NSString *)key
  {
    if ([key isEqualToString:@"pid"]) {
        self.pid = 0;
    }
    else {
        [super setNilValueForKey:key];
    }

  }
  @end

Answer 1

Using scalar values in core data is a bit more work than using the recommended NSNumber. This is described in detail in this section of the Core Data Programming Guide.

I strongly recommend you switch this property to NSNumber. Your assignment statement would then be:

shEnt.pid = [NSNumber numberWithInt:[processInfo processIdentifier]];