【Swift】Swift4でFirebaseに触ってみる

■はじめに

Firebaseに触ってみたくなったので、以下記事を参考にさせていただき試してみました。

■Swift4での書き方

上記記事はとても丁寧な説明なのでスムーズに試すことができるかと思いますが、Swift4だと若干書き方が異なるため下記コードを残しておきます。上記記事を読んでもわからない方がもしいれば、参考にしていただければと思います。

（1）AppDelegate.swift

import UIKit
import Firebase

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?
    
    func application(_ application: UIApplication,
                     didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?)
        -> Bool {
            FirebaseApp.configure()
            return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    }
}

（2）ViewController.swift

import UIKit
import Firebase

class ViewController: UIViewController {
    
    @IBOutlet weak var testField: UITextField!
    @IBOutlet weak var ageLabel: UILabel!
    
    
    // インスタンス変数
    var DBRef: DatabaseReference!
    
    override func viewDidLoad() {
        super.viewDidLoad()
    　　// Do any additional setup after loading the view, typically from a nib.
        
        // インスタンスを作成
        DBRef = Database.database().reference()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // 要素（年齢）の追加
    @IBAction func addtest(_ sender: Any) {
        let age: Int = Int(testField.text!)!
        let data = ["age": age]
        DBRef.child("user/01").setValue(data)
        
        let defaultPlace = DBRef.child("user/01/age")
        defaultPlace.observe(.value) { (snap: DataSnapshot) in
　　　　 self.ageLabel.text = (snap.value! as AnyObject).description}
    }
    
    // 要素（名前）の更新
    @IBAction func testRenew(_ sender: Any) {
        let data = ["name": testField.text!]
        DBRef.child("user/01").updateChildValues(data)
    }
    
    // 要素（名前）の削除
    @IBAction func testRemove(_ sender: Any) {
        DBRef.child("user/01/name").removeValue()
    }
}

■おわりに

FirebaseはDatabase以外にも様々な機能があり面白そうなので、別途試していきたいと思います。

■関連リンク

・Firebase

・Swiftで始めるFirebase入門 - Qiita

Swift・iOS

Swiftを中心に学んだことを記録に残すブログです。技術に関係ない記事もたまに書いています。

【Swift】Swift4でFirebaseに触ってみる