Using Swift to Seed a Core Data Database

 1public class DataHelper {
 2    let context: NSManagedObjectContext
 3    
 4    init(context: NSManagedObjectContext) {
 5        self.context = context
 6    }
 7    
 8// ...
 9
10}

 1public class DataHelper {
 2
 3// ...
 4
 5    private func seedZoos() {
 6        let zoos = [
 7            (name: "Oklahoma City Zoo", location: "Oklahoma City, OK"),
 8            (name: "Lowry Park Zoo", location: "Tampa, FL"),
 9            (name: "San Diego Zoo", location: "San Diego, CA")
10        ]
11        
12        for zoo in zoos {
13            let newZoo = NSEntityDescription.insertNewObjectForEntityForName("Zoo", inManagedObjectContext: context) as! Zoo
14            newZoo.name = zoo.name
15            newZoo.location = zoo.location
16        }
17        
18        do {
19            try context.save()
20        } catch _ {
21        }
22    }
23
24// ...
25
26}

 1public class DataHelper {
 2
 3// ...
 4
 5    public func printAllZoos() {
 6        let zooFetchRequest = NSFetchRequest(entityName: "Zoo")
 7        let primarySortDescriptor = NSSortDescriptor(key: "name", ascending: true)
 8        
 9        zooFetchRequest.sortDescriptors = [primarySortDescriptor]
10        
11        let allZoos = (try! context.executeFetchRequest(zooFetchRequest)) as! [Zoo]
12        
13        for zoo in allZoos {
14            print("Zoo Name: \(zoo.name)\nLocation: \(zoo.location) \n-------\n", terminator: "")
15        }
16    }
17
18// ...
19
20}

 1public class DataHelper {
 2
 3// ...
 4
 5    private func seedAnimals() {
 6        // Grab Classifications
 7        let classificationFetchRequest = NSFetchRequest(entityName: "Classification")
 8        let allClassifications = (try! context.executeFetchRequest(classificationFetchRequest)) as! [Classification]
 9
10        let manatee = allClassifications.filter({(c: Classification) -> Bool in
11            return c.family == "Trichechidae"
12        }).first
13        
14        // Same pattern for monkey and bat
15        
16        // Grab Zoos
17        let zooFetchRequest = NSFetchRequest(entityName: "Zoo")
18        let allZoos = (try! context.executeFetchRequest(zooFetchRequest)) as! [Zoo]
19        
20        let oklahomaCityZoo = allZoos.filter({ (z: Zoo) -> Bool in
21            return z.name == "Oklahoma City Zoo"
22        }).first
23        
24        // Same pattern for San Diego Zoo and Lowry Park Zoo
25        
26        // Create an array of "animal" tuples, assigning
27        // whatever Classification and Zoo make sense
28        let animals = [
29            (commonName: "Pygmy Fruit-eating Bat", habitat: "Flying Mamals Exhibit", classification: bat!, zoos: NSSet(array: [lowryParkZoo!, oklahomaCityZoo!, sanDiegoZoo!])),
30            (commonName: "Mantled Howler", habitat: "Primate Exhibit", classification: monkey!, zoos: NSSet(array: [sanDiegoZoo!, lowryParkZoo!])),
31            (commonName: "Geoffroy’s Spider Monkey", habitat: "Primate Exhibit", classification: monkey!, zoos: NSSet(array: [sanDiegoZoo!])),
32            (commonName: "West Indian Manatee", habitat: "Aquatic Mamals Exhibit", classification: manatee!, zoos: NSSet(array: [lowryParkZoo!]))
33        ]
34        
35        // Create -actual- Animal instances and insert them
36        for animal in animals {
37            let newAnimal = NSEntityDescription.insertNewObjectForEntityForName("Animal", inManagedObjectContext: context) as! Animal
38            newAnimal.commonName = animal.commonName
39            newAnimal.habitat = animal.habitat
40            newAnimal.classification = animal.classification
41            newAnimal.zoos = animal.zoos
42        }
43        
44        do {
45            try context.save()
46        } catch _ {
47        }
48    }
49
50// ...
51
52}

 1func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
 2        // Override point for customization after application launch.
 3        
 4        let dataHelper = DataHelper(context: self.managedObjectContext)
 5        dataHelper.seedDataStore()
 6        
 7        dataHelper.printAllZoos()
 8        dataHelper.printAllClassifications()
 9        dataHelper.printAllAnimals()
10        
11        return true
12    }

 1lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
 2        // The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
 3        // Create the coordinator and store
 4        let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
 5        let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("Zootastic.sqlite")
 6        
 7        do {
 8            try NSFileManager.defaultManager().removeItemAtURL(url)
 9        } catch _ {
10        }
11
12        
13        var failureReason = "There was an error creating or loading the application's saved data."
14        do {
15            try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
16        } catch {
17            // Report any error we got.
18            var dict = [String: AnyObject]()
19            dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
20            dict[NSLocalizedFailureReasonErrorKey] = failureReason
21            
22            dict[NSUnderlyingErrorKey] = error as NSError
23            let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
24            // Replace this with code to handle the error appropriately.
25            // 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.
26            NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
27            abort()
28        }
29        
30        return coordinator
31        }()