【Swift】【Realm】ToDoListAppの作り方

Storyboardのレイアウトの作成

各コントローラーのコード

ViewController

import UIKit
import RealmSwift

class ToDoListItem: Object {
    @objc dynamic var item: String = ""
    @objc dynamic var date: Date = Date()
}

class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
    
    @IBOutlet weak var table: UITableView!
    
    private var data = [ToDoListItem]()
    private let realm = try! Realm()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        data = realm.objects(ToDoListItem.self).map({ $0 })
        table.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
    }

    //Mark: Table
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return data.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
        cell.textLabel?.text = data[indexPath.row].item
        return cell
    }
    
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
        let item = data[indexPath.row]
        guard let vc = storyboard?.instantiateViewController(identifier: "view") as? ViewViewController else { return }
        vc.item = item
        vc.deletionHandler = { [weak self] in self?.refresh() }
        vc.navigationItem.largeTitleDisplayMode = .never
        vc.title = item.item
        navigationController?.pushViewController(vc, animated: true)
    }
    
    @IBAction func didTapAddButton(_ sender: Any) {
        guard let vc = storyboard?.instantiateViewController(identifier: "enter") as? EntryViewController else { return }
        vc.completionHandler = { [weak self] in self?.refresh()
        }
        vc.title = "New Item"
        vc.navigationItem.largeTitleDisplayMode = .never
        navigationController?.pushViewController(vc, animated: true)
    }
    
    func refresh() {
        data = realm.objects(ToDoListItem.self).map({ $0 })
        table.reloadData()
    }
}

EntryViewController

import UIKit
import RealmSwift

class EntryViewController: UIViewController, UITextFieldDelegate {
    
    @IBOutlet weak var textField: UITextField!
    @IBOutlet weak var datePicker: UIDatePicker!
    
    private let realm = try! Realm()
    public var completionHandler: (() -> Void)?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        textField.becomeFirstResponder()
        textField.delegate = self
        datePicker.setDate(Date(), animated: true)
        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Save", style: .done, target: self, action: #selector(didTapSaveButton))
        
    }
    
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true
    }
    
    @objc func didTapSaveButton() {
        if let text = textField.text, !text.isEmpty {
            let date = datePicker.date
            realm.beginWrite()
            let newItem = ToDoListItem()
            newItem.date = date
            newItem.item = text
            realm.add(newItem)
            try! realm.commitWrite()
            
            completionHandler?()
            navigationController?.popViewController(animated: true)
        }
        else {
            print("Add something")
        }
    }
}

ViewViewController

import UIKit
import RealmSwift

class ViewViewController: UIViewController {
    
    public var item: ToDoListItem?
    
    public var deletionHandler: (() -> Void)?
    
    @IBOutlet weak var itemLabel: UILabel!
    @IBOutlet weak var dateLabel: UILabel!
    
    private let realm = try! Realm()
    
    static let dateFormatter: DateFormatter = {
        let dateFormatter = DateFormatter()
        dateFormatter.dateStyle = .medium
        return dateFormatter
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        itemLabel.text = item?.item
        dateLabel.text = Self.dateFormatter.string(from: item!.date)
        navigationItem.rightBarButtonItem  = UIBarButtonItem(barButtonSystemItem: .trash, target: self, action: #selector(didTapDelete))
    }
    
    @objc private func didTapDelete() {
        guard let myItem = self.item else {
            return
        }
        realm.beginWrite()
        realm.delete(myItem)
        try! realm.commitWrite()
        
        deletionHandler?()
        navigationController?.popViewController(animated: true)
    }
    
}