Swift webview: How to call correctly swift code from javascript?

Question

I\'m trying to make my javascript interact with swift code but unfortunately i didn\'t succeed.

For the moment, i just tried to change the headers colors and displa

Answer 1

You have everything set up properly, but you aren't giving your WKWebViewConfiguration instance to the WKWebView. Since the configuration has the details of the Javascript/Swift bridge, you can't talk back and forth.

override func loadView() {
    // ...
    var config = WKWebViewConfiguration()
    config.userContentController = contentController

    self.webView = WKWebView(frame: self.view.frame, configuration: config)
    self.view = self.webView!
}

Answer 2

my 2 cents, using a javascript callback with JSON ... for full class definition and layout, refer to adam's code

import UIKit
import WebKit

class ViewController: UIViewController, WKScriptMessageHandler {
    var webView: WKWebView?
    ...

then

override func loadView() {
    let theConfiguration = WKWebViewConfiguration()
    let contentController = theConfiguration.userContentController

    // alert fix, at start to allow a JS script to overwrite it
    contentController.addUserScript( WKUserScript(
        source: "window.alert = function(message){window.webkit.messageHandlers.messageBox.postMessage({message:message});};",
        injectionTime: WKUserScriptInjectionTime.AtDocumentStart,
        forMainFrameOnly: true
    ) )
    contentController.addScriptMessageHandler(self, name: "messageBox")

    self.webView = WKWebView(frame: self.view.frame, configuration: theConfiguration)

    // and here things like: self.webView!.navigationDelegate = self
    self.view = self.webView!  // fill controllers view
}

and specifically

func userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) {

    if message.name == "messageBox" {
        let sentData = message.body as! Dictionary<String, String>

        let message:String? = sentData["message"]

        let alertController = UIAlertController(title: nil, message: message, preferredStyle: UIAlertControllerStyle.Alert)
        alertController.addAction(UIAlertAction(title: NSLocalizedString("OK", comment:"btnOK"), style: .Default, handler: nil))
        self.presentViewController(alertController, animated: true) {}
    }
}