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iOS Build a Diary App Using Core Data Inserting and Saving Data Inserting a Managed Object

Posted by Alex Cevallos
Alex Cevallos
16,551 Points

When is -(NSURL *)applicationDocumentsDirectory called?

Hey everyone! so when the view is dismissed, -(void)saveContext is called. Which is this:

  • (void)saveContext { NSError *error = nil; NSManagedObjectContext *managedObjectContext = self.managedObjectContext; if (managedObjectContext != nil) { if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) { // Replace this implementation with code to handle the error appropriately. // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } } }

how is -(NSURL *)applicationDocumentsDirectory called from that ? Somehow the console logs everything out.. but I am missing where applicationDocumentsDirectory is called ?

1 Answer

Robin Malhotra
Robin Malhotra
14,883 Points
Robin Malhotra
Robin Malhotra
14,883 Points

I think NSPersistent Store and the backend structures of CoreData handle that. Instead of Core Data, if you're dealing with static stuff, I recommend using something like this

''' @try { NSFileManager *fileMgr = [NSFileManager defaultManager]; NSString *dbPath = [[[NSBundle mainBundle] resourcePath ]stringByAppendingPathComponent:@"test2.sqlite"]; BOOL success = [fileMgr fileExistsAtPath:dbPath]; if(!success) { NSLog(@"Cannot locate database file '%@'.", dbPath); } if(!(sqlite3_open([dbPath UTF8String], &db) == SQLITE_OK)) { NSLog(@"An error has occured: %s", sqlite3_errmsg(db));

        }

    NSString *myString = [NSString stringWithFormat:@"SELECT * FROM  event WHERE Cat = %@ ORDER By Date", ofType];// and Date = '%@',ofdate
    const char *sql= [myString cStringUsingEncoding:NSASCIIStringEncoding];


    if(sqlite3_prepare(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK)
        {
        NSLog(@"Problem with prepare statement:  %s", sqlite3_errmsg(db));
        }else{

            while (sqlite3_step(sqlStatement)==SQLITE_ROW) {
                Event * event = [[Event alloc] init];
                event.name = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,0)];
                event.location = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,1)];
                event.startTime = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 2)];
                event.endTime = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 3)];
                event.catogory = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 4)];
                event.date = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 5)];
                event.text = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 6)];
                event.info = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 7)];
                [theevents addObject:event];
            }
        }

'''