Storing with CoreData - ios

Question

my app is very simple: I have one tableview to store recipe *names and, for each recipe name, another tableview with several *ingredients for each recipe.
I already managed to save the name and the ingredients with CoreData, but here is the problem: when I press to add a NEW recipe name and enter the ingredients table view area, the ingredients saved for the previous recipe are there! How do I clear the table view to start a new one?
Also, my table views does not get updated immediately, I have to close the app and open it again. How do I fix it?
Note: If my question is too hard to understand, I can post some code! Thanks in advance, everyone =)
EDIT
code:
import UIKit
import CoreData
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, NSFetchedResultsControllerDelegate {
#IBOutlet var tableView: UITableView!
var imageList: [UIImage] = []
var moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
var fetchedResultsController: NSFetchedResultsController?
override func viewDidLoad() {
fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchName(), managedObjectContext: moc!, sectionNameKeyPath: nil, cacheName: nil)
fetchedResultsController?.delegate = self
fetchedResultsController?.performFetch(nil)
tableView.reloadData()
}
func fetchName() -> NSFetchRequest {
var fetchRequest = NSFetchRequest(entityName: "Details")
let sortDescriptor = NSSortDescriptor(key: "name", ascending: true)
fetchRequest.predicate = nil
fetchRequest.sortDescriptors = [sortDescriptor]
fetchRequest.fetchBatchSize = 20
return fetchRequest
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return fetchedResultsController?.sections?[section].numberOfObjects ?? 0
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("recipeCell", forIndexPath: indexPath) as! UITableViewCell
if let recipeCell = fetchedResultsController?.objectAtIndexPath(indexPath) as? Details {
cell.textLabel?.text = recipeCell.name
}
return cell
}
}
-
import UIKit
import CoreData
class InfoViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate, UITableViewDelegate {
#IBOutlet var nameField: UITextField!
#IBOutlet var imageView: UIImageView!
var moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
override func viewDidLoad() {
super.viewDidLoad()
//Pick the image by tap
let tapGestureRecognizer: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "chooseImage:")
tapGestureRecognizer.numberOfTapsRequired = 1
imageView.addGestureRecognizer(tapGestureRecognizer)
imageView.userInteractionEnabled = true
}
//Pick the image by tapping, accessing the photoLibrary
func chooseImage(recognizer: UITapGestureRecognizer) {
let imagePicker: UIImagePickerController = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
self.presentViewController(imagePicker, animated: true, completion: nil)
}
//Put the selected image into the screen
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject:AnyObject]) {
let pickedImage: UIImage = (info as NSDictionary).objectForKey(UIImagePickerControllerOriginalImage) as! UIImage
// small picture
let smallPicture = scaleImageWith(pickedImage, newSize: CGSizeMake(288,148))
var sizeOfImageView:CGRect = imageView.frame
sizeOfImageView.size = smallPicture.size
imageView.frame = sizeOfImageView
imageView.image = smallPicture
picker.dismissViewControllerAnimated(true, completion: nil)
}
func imagePickerControllerDidCancel(picker: UIImagePickerController) {
picker.dismissViewControllerAnimated(true, completion: nil)
}
func scaleImageWith(image:UIImage, newSize: CGSize) -> UIImage {
UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0)
image.drawInRect(CGRectMake(0,0, newSize.width, newSize.height))
let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
#IBAction func addButton(sender: AnyObject) {
let entityDescription = NSEntityDescription.entityForName("Details", inManagedObjectContext: moc!)
let details = Details(entity: entityDescription!, insertIntoManagedObjectContext: moc)
details.name = nameField.text
var error: NSError?
moc?.save(&error)
if let err = error {
var status = err.localizedFailureReason
println("\(status)")
} else {
println("Ingredient \(nameField.text) saved successfully!")
}
if let navigation = navigationController {
navigation.popViewControllerAnimated(true)
}
}
}
-
import UIKit
import CoreData
class IngredientListViewController: UIViewController, NSFetchedResultsControllerDelegate {
#IBOutlet var tableView: UITableView!
var moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
var fetchedResultsController: NSFetchedResultsController?
override func viewDidLoad() {
super.viewDidLoad()
fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchIngredient(), managedObjectContext: moc!, sectionNameKeyPath: nil, cacheName: nil)
fetchedResultsController?.delegate = self
fetchedResultsController?.performFetch(nil)
tableView.reloadData()
}
func fetchIngredient() -> NSFetchRequest {
var fetchRequest = NSFetchRequest(entityName: "Ingredients")
let sortDescriptor = NSSortDescriptor(key: "ingredients", ascending: true)
fetchRequest.predicate = nil
fetchRequest.sortDescriptors = [sortDescriptor]
fetchRequest.fetchBatchSize = 20
return fetchRequest
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return fetchedResultsController?.sections?[section].numberOfObjects ?? 0
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("ingCell", forIndexPath: indexPath) as! UITableViewCell
if let recipeCell = fetchedResultsController?.objectAtIndexPath(indexPath) as? Ingredients {
cell.textLabel?.text = recipeCell.ingredients
}
return cell
}
}
-
import UIKit
import CoreData
class IngredientViewController: UIViewController {
#IBOutlet var nameField: UITextField!
var moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
#IBAction func addButton(sender: AnyObject) {
let entityDescription = NSEntityDescription.entityForName("Ingredients", inManagedObjectContext: moc!)
let details = Ingredients(entity: entityDescription!, insertIntoManagedObjectContext: moc)
details.ingredients = nameField.text
var error: NSError?
moc?.save(&error)
if let err = error {
var status = err.localizedFailureReason
println("\(status)")
} else {
println("Ingredient \(nameField.text) saved successfully!")
}
if let navigation = navigationController {
navigation.popViewControllerAnimated(true)
}
}
}
and models:
import Foundation
import CoreData
class Ingredients: NSManagedObject {
#NSManaged var ingredients: String
#NSManaged var relationship: NSSet
}
import Foundation
import CoreData
class Details: NSManagedObject {
#NSManaged var name: String
#NSManaged var relationship: Ingredients
}

Answer 1

In outline:
You need to amend your model: currently each Details object can have only one Ingredients. I suspect you need this relationship to be "to many" so a recipe can have many ingredients.
You need to add a var (of type Details?) to your IngredientListViewController. This will represent the chosen Recipe. (eg. var chosenRecipe : Details?)
In fetchIngredient, you need to add a predicate to the fetch, to limit the results to the chosen recipe. eg. fetch.predicate = NSPredicate(format:"ANY relationship == %#", chosenRecipe)
Before segueing to this VC, you need to set the chosenRecipe (probably in prepareForSegue, or didSelectRowAtIndexPath in the preceding table view).
To get your TV to update automatically, use the fetchedResultsController delegate methods. (Have you implemented these?)