deltachat-ios/deltachat-ios/Controller/WebViewViewController.swift

import UIKit
import WebKit

class WebViewViewController: UIViewController, WKNavigationDelegate {

    public lazy var webView: WKWebView = {
        let preferences = WKPreferences()
        preferences.javaScriptEnabled = false

        let configuration = WKWebViewConfiguration()
        configuration.preferences = preferences

        let view = WKWebView(frame: .zero, configuration: configuration)
        view.navigationDelegate = self
        return view
    }()

    init() {
        super.init(nibName: nil, bundle: nil)
        hidesBottomBarWhenPushed = true
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
        if navigationAction.navigationType == .linkActivated,
           let url = navigationAction.request.url,
            url.host != nil,
            UIApplication.shared.canOpenURL(url) {
            UIApplication.shared.open(url)
            decisionHandler(.cancel)
            return
        }
        decisionHandler(.allow)
    }

    // MARK: - lifecycle
    override func viewDidLoad() {
        super.viewDidLoad()
        setupSubviews()
    }


    // MARK: - setup + configuration
    private func setupSubviews() {
        view.addSubview(webView)
        webView.translatesAutoresizingMaskIntoConstraints = false
        webView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 0).isActive = true
        webView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 0).isActive = true
        webView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: 0).isActive = true
        webView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true
    }
}