Swift: Natively Detect if App has Crashed

Question

I have searched around, but have yet to find an answer that doesn\'t direct me towards a 3rd party service. I do not need anything intricate, just to save a value in N

Answer 1

Details

• swift 4.2
• Xcode 10.1 (10B61)

Solution 1

https://github.com/zixun/CrashEye/blob/master/CrashEye/Classes/CrashEye.swift

Full sample of solution 1

!!! DO NOT FORGET TO COPY (or INSTALL POD) SOLUTION CODE !!!

AppDelegate.swift

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        CrashEye.add(delegate: self)
        return true
    }
}

extension AppDelegate: CrashEyeDelegate {
    func crashEyeDidCatchCrash(with model: CrashModel) {
        UserDefaults.standard.set(model.reason + "(\(Date()))", forKey: "crash")
    }
}

ViewController.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let button = UIButton(frame: CGRect(x: 40, y: 40, width: 80, height: 44))
        button.setTitle("BOOOM", for: .normal)
        button.setTitleColor(.blue, for: .normal)
        button.addTarget(self, action: #selector(boomButtonTouchedUpInside), for: .touchUpInside)
        view.addSubview(button)
    }

    override func viewDidAppear(_ animated: Bool) {
        if let date = UserDefaults.standard.string(forKey: "crash") {
            let alert = UIAlertController(title: "", message: date, preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
            present(alert, animated: true)
        }
    }

    @objc func boomButtonTouchedUpInside(_ sender: Any) {
        let arr = [1, 2, 3]
        let elem = arr[4]
    }
}

Solution 2. Crashlytics

Install Crashlytics

Full sample of solution 2

AppDelegate.swift

import UIKit
import Fabric
import Crashlytics

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        Crashlytics.sharedInstance().delegate = self
        Fabric.with([Crashlytics.self])
        return true
    }
}

extension AppDelegate: CrashlyticsDelegate {
    func crashlyticsDidDetectReport(forLastExecution report: CLSReport) {
        let alert = UIAlertController(title: "\(report.dateCreated)", message: report.identifier, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
        DispatchQueue.global(qos: .background).async {
            sleep(3)
            DispatchQueue.main.async {
                self.window?.rootViewController?.present(alert, animated: true)
            }
        }
    }
}

ViewController.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let button = UIButton(frame: CGRect(x: 40, y: 40, width: 80, height: 44))
        button.setTitle("BOOOM", for: .normal)
        button.setTitleColor(.blue, for: .normal)
        button.addTarget(self, action: #selector(boomButtonTouchedUpInside), for: .touchUpInside)
        view.addSubview(button)
    }

    @objc func boomButtonTouchedUpInside(_ sender: Any) {
        let arr = [1, 2, 3]
        let elem = arr[4]
    }
}

Results

1. Launch app
2. Push "Booom" button (app will crash)

3. Lunch app again