Core Data - Core Data is a framework that you use to manage the data model layer objects or instance Context in your application. It provides generalized and automated data stores solutions to common tasks associated with object life cycle and object graph management, including persistence.
Completely Tutorial for Swift 4 and iOS 11.
Gating Start Goto Xcode and create New iOS Project on single view. Project Name CoreDataSwift
or Checked Use Core Data
On click Main.Storyboard in Interface builder click on project navigation Editor - Embed In - Navigation controller.
Then After click on Navigation ViewController and next Drag TableView in to ViewController.
import UIKit
import CoreData
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Next IBOutlet Property TableView UITableView is tableView and register tableView Nib viewDidLoad
@IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
title = "Thie List"
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
// Do any additional setup after loading the view, typically from a nib.
}
// UITableViewDataSource
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return people.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let person = people[indexPath.row]
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
cell.textLabel?.text = person.value(forKeyPath: "name") as? String
return cell
}
Start build and Run Project CoreDataSwift app ViewController look like Simulator
Now Use CoreData Modeling
Xcode automatically create data model
Create New Entity name "Person" and create attributes "name" type string
Now drag a Bar Button Item Add viewController Navigation bar
Now Create a addName function on to Add BarButtonItem
@IBAction func addName(_ sender: Any) {
let alert = UIAlertController(title: "New Name",message: "Add a new name", preferredStyle: .alert)
let saveAction = UIAlertAction(title: "Save", style: .default) {
[unowned self] action in
guard let textField = alert.textFields?.first, let nameToSave = textField.text else {
return
}
self.save(name: nameToSave)
self.tableView.reloadData()
}
let cancelAction = UIAlertAction(title: "Cancel", style: .default)
alert.addTextField()
alert.addAction(saveAction)
alert.addAction(cancelAction)
present(alert, animated: true)
}
Saving Core Data
Import CoreData
Now Create two var name, people mutable array
import UIKit
import CoreData
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var names: [String] = []
var people: [NSManagedObject] = []
@IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
title = "Thie List"
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
// Do any additional setup after loading the view, typically from a nib.
}
Create save func to manage saving core data
func save(name: String) {
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
return
}
let managedContext = appDelegate.persistentContainer.viewContext
let entity = NSEntityDescription.entity(forEntityName: "Person", in: managedContext)!
let person = NSManagedObject(entity: entity, insertInto: managedContext)
person.setValue(name, forKeyPath: "name")
do {
try managedContext.save()
people.append(person)
} catch let error as NSError {
print("Could not save. \(error), \(error.userInfo)")
}
}
Full Core data ViewController File
//
// ViewController.swift
// CoreDataSwift
//
// Created by Praveen Raman on 12/28/17.
// Copyright © 2017 Apple. All rights reserved.
//
import UIKit
import CoreData
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var names: [String] = []
var people: [NSManagedObject] = []
@IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
title = "Thie List"
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
// Do any additional setup after loading the view, typically from a nib.
}
// UITableViewDataSource
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return people.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let person = people[indexPath.row]
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
cell.textLabel?.text = person.value(forKeyPath: "name") as? String
return cell
}
@IBAction func addName(_ sender: Any) {
let alert = UIAlertController(title: "New Name",message: "Add a new name", preferredStyle: .alert)
let saveAction = UIAlertAction(title: "Save", style: .default) {
[unowned self] action in
guard let textField = alert.textFields?.first, let nameToSave = textField.text else {
return
}
self.save(name: nameToSave)
self.tableView.reloadData()
}
let cancelAction = UIAlertAction(title: "Cancel", style: .default)
alert.addTextField()
alert.addAction(saveAction)
alert.addAction(cancelAction)
present(alert, animated: true)
}
func save(name: String) {
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
return
}
// 1
let managedContext = appDelegate.persistentContainer.viewContext
// 2
let entity = NSEntityDescription.entity(forEntityName: "Person", in: managedContext)!
let person = NSManagedObject(entity: entity, insertInto: managedContext)
// 3
person.setValue(name, forKeyPath: "name")
// 4
do {
try managedContext.save()
people.append(person)
} catch let error as NSError {
print("Could not save. \(error), \(error.userInfo)")
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Output:-
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