Allow Download on IOS App

Question

I started developing for IOS and I can’t download inside a Webview using Xcode in the Swift language.

The Code is very simple, it opens a website, where it contains a button to download an Image file.

But after clicking the button, it opens the image on a white page. If I press the image, it appears the save option, but when I click the Emulator closes and an Error message appears (Thread 9: signal SIGABRT).

I’ve turned the Internet upside down and looked at other answers right here on Stack Overflow, but nothing worked for me.

import UIKit
import WebKit

class ViewController: UIViewController, WKUIDelegate {


    var webView: WKWebView!

    override func loadView() {
        let webConfiguration = WKWebViewConfiguration()
        webView = WKWebView(frame: .zero, configuration: webConfiguration)
        webView.uiDelegate = self
        view = webView
    }
    override func viewDidLoad() {
        super.viewDidLoad()

        let myURL = URL(string:"https://erroemdownloadios.com")
        let myRequest = URLRequest(url: myURL!)
        webView.load(myRequest)


    } 
}

Answer 1

I would recommend you to have your Viewcontroller implement WKNavigationDelegate. Nessa delegate, you can use the method:

func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void)

In the navigationAction, you can pick up the URL to which the browser will navigate. If it is an image (you can know this by pathExtension or some other regex in the URL), you can use to download the image via code (with URLSession or Data), and save in user photos.

EDIT (13/09/2019):

You can intercept URL changes this way:

import UIKit
import WebKit

class ViewController: UIViewController, WKNavigationDelegate {


    var webView: WKWebView!

    override func loadView() {
        let webConfiguration = WKWebViewConfiguration()
        webView = WKWebView(frame: .zero, configuration: webConfiguration)
        webView.naivgationDelegate = self
        view = webView
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        let myURL = URL(string:"https://erroemdownloadios.com")
        let myRequest = URLRequest(url: myURL!)
        webView.load(myRequest)


    } 

    func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
        guard let requestURL = navigationAction.request.url else {
            decisionHandler(.allow)
            return
        }

        //Aqui você tem a URL, e pode fazer o que quiser com ela.

        decisionHandler(.allow)
    }
}