NSManagedObject Subclasses - Beginning Core Data

code.txt

PeopleTableViewController.swift
------
import UIKit
import CoreData

class PeopleTableViewController: UITableViewController {
  var managedObjectContext: NSManagedObjectController!
  var people = [NSManagedObject]()
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    title = "People"
    
    reloadData()
  }
  
  func reloadData() {
    let fetchRequest = NSFetchRequest(entityName: "Person")
    
    do {
      let results = try managedObjectContext.
        executeFetchRequest(fetchRequest) as? [NSManagedObject] {
        people = results  
      }
    } catch {
      fatalError("There was an error fetching the list of people!")
    }
  }
}

DevicesTableViewController.swift
-----
import UIKit
import CoreData

class DevicesTabeViewController: UITableViewConroller {
  var managedObjectContext: NSManagedObjectContext!
  var devices = [Device]()
  
  override func viewdDidLoad() {
    super.viewDidLoad()
    
    title = "Devices"
    navigationItem.rightBarButtonItem = UIBarButtonItem
      (barButtonSystemItem: .Add, target: self, action:
      "addDevice:")
  }
  
  override func viewWillAppear(animated: Bool {
    super.viewWillAppear(animated)
    
    reloadData()
    tableView.reloadData()
  }
  
  func reloadData() {
    let fetchRequest = NSFetchRequest(entityName: "Device")
    
    do {
      if let results = try managedObjectContext,
        executeFetchRequest(fetchRequest) as? [Device] {
        devices = results
      }
    } catch {
      fatalError("There was an error fetching the list of devices!")
    }
  }
  
  // MARK: - Table view data source
  
  override func numberOfSectionsInTableView(tablewView: UITableView) -> Int {
    return 1
  }
  
  override func tableView(tableView: UITableView, 
    cellForRowAtIndexPath indexPath: NSIndexPath) ->
    UITableViewCell {
    let cell = 
      tableVIew.dequeueResuableCellWithIdentifier("DeviceCell", 
      forIndexPath: indexPath)
    
    let decice = decices[indexPath.row]
    
    cell.textLabel?.text = device.name
    cell.detailTextLabel?.text = device.deviceType
    
    return cell
  }
  
  // MARK: - Actions & Segues
  
  func addDevice(sender: AnyObject?) {
    performSegueWithIdentifier("deviceDetail", sender: self)
  }
  
  override func prepareForSegue(segue: UIStoryboardSeque, sender: 
    AnyObject? {
    if let dest = segue.destinationViewController as? 
      DeviceDetailTableViewController {
      ???????
    }   
  }
}

AppDelegate.swift
-----
import UIKit
import CoreData

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

  var window: UIWindow?
  
  func application(application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    
    let fetchRequest = NSFetchRequest(entityName: "Device")
    do {
      let results = try managedObjectContext.executeFetchRequest(fetchRequest)
      if results.count == 0 {
        addTestData()
       }
    } catch {
      fatalError("Error fetching data!")
    }
    
    if let tab = window?.rootViewController as? 
      UITabBarController {
      for child in tab.viewControllers ?? [] {
        if let child = child as? UINavigationController, top = child.topViewController {
          if top.respondsToSelector("setManagedObjectContext:") {
            top.performSelector("setManagedObjectContext", withObject: managedObjectContext)
          }
        }
      }
    }
    
    return true
  }
  
    func addTestData() {
        let managedObjectContext = persistentContainer.viewContext

        // Reference to Core Data Device entity
        guard let entity =
            NSEntityDescription.entity(forEntityName: "Device", in: managedObjectContext) else {
                fatalError("Could not find entry description!")
        }
        
        for i in 1...10 {
            // Create an instance of the managed object and set properties into the context
            let device = Device(entity: entity, insertInto: managedObjectContext)
            
            // Add test data values
            device.name = "Some Device #\(i)"
            device.deviceType = (i % 3 == 0 ? "Watch" : "iPhone"
        }
        
        let bob = NSManagedObject(entity: personEntity, insertIntoManagedObjectContext: managedObjectContext)
        bob.setValue("Bob", forKey: "name")
        let jane = NSManagedObject(entity: personEntity, insertIntoManagedObjectContext: managedObjectContext)
        jane.setValue("Jane", forKey: "name")
        
        saveContext()
    }
    
}


##### 6:03
MyDevices data model
Devices - same as code part 1
person - Name - String

Editor Menu - Create NSManagedObject SubClass - select only - mydevices - create both device + people

In generate class - remove question marks from deviceType + name + same for person

####### 8:04 

- https://www.youtube.com/watch?v=62A-zAzc0aE&frags=wn