Greg Williams Greg Williams - 3 months ago 14
iOS Question

iOS - How to create WKWebView Back Button programmatically?

I am attempting to create a back button for my iOS WKWebView app so that way when the user clicks on the button it takes them to the previous WKWebView page. I have found numerous tutorials on how to do this with IB but not with straight code. This is what I have so far:

Original ViewController.swift:

import UIKit
import WebKit

class ViewController: UIViewController, WKNavigationDelegate {

private var webView: WKWebView!

let wv = WKWebView(frame: UIScreen.mainScreen().bounds) //needed for working webview

self.webView = WKWebView(frame: frame)
self.webView.navigationDelegate = self

func rightbutton(text: String, action: Selector) {
let rightButton = UIBarButtonItem(title: text, style: .Plain, target: self, action: action)
self.navigationItem.rightBarButtonItem = rightButton
}

func action() {
if self.webView.canGoBack {
print ("Can go back")
self.webView.goBack()
self.webView.reload()

} else {
print ( "Can't go back")
}
}


override func viewDidLoad() {
super.viewDidLoad()
guard let url = NSURL(string: "http://communionchapelefca.org/app-home") else { return }
wv.navigationDelegate = self
wv.loadRequest(NSURLRequest(URL: url))
view.addSubview(wv)


webView.goBack()
webView.reload()



prefButton()
//backButton()

NSNotificationCenter.defaultCenter().addObserver(self,
selector: "receiveNotification:",
name: "BeaconServiceRegionEnter",
object: nil)

NSNotificationCenter.defaultCenter().addObserver(self,
selector: "receiveNotification:",
name: "BeaconServiceRegionUpdate",
object: nil)

NSNotificationCenter.defaultCenter().addObserver(self,
selector: "receiveNotification:",
name: "BeaconServiceRegionExit",
object: nil)

}

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

func prefButton () {
let image = UIImage(named: "icon-pref128") as UIImage?
let button = UIButton(type: UIButtonType.Custom) as UIButton
let screenSize: CGRect = UIScreen.mainScreen().bounds
let screenWidth = screenSize.width
let screenHeight = screenSize.height

button.frame = CGRectMake(screenWidth * 0.85, screenHeight * 0.90, 56, 56) // (X, Y, Height, Width)
button.setImage(image, forState: .Normal)
button.addTarget(self, action: "buttonClicked:", forControlEvents:.TouchUpInside)
self.view.addSubview(button)
}

func buttonClicked(sender:UIButton)
{
UIApplication.sharedApplication().openURL(NSURL(string: UIApplicationOpenSettingsURLString)!)
}

func receiveNotification(notification: NSNotification) {
print(notification.userInfo)
}

func webView(webView: WKWebView, decidePolicyForNavigationAction navigationAction: WKNavigationAction, decisionHandler: (WKNavigationActionPolicy) -> Void) {
if navigationAction.navigationType == .LinkActivated {
if let newURL = navigationAction.request.URL,
host = newURL.host where !host.containsString("communionchapelefca.org") &&
UIApplication.sharedApplication().canOpenURL(newURL) {
if UIApplication.sharedApplication().openURL(newURL) {
print(newURL)
print("Redirected to browser. No need to open it locally")
decisionHandler(.Cancel)
} else {
print("browser can not url. allow it to open locally")
decisionHandler(.Allow)
}
} else {
print("Open it locally")
decisionHandler(.Allow)
}
} else {
print("not a user click")
decisionHandler(.Allow)
}
}

}


Any suggestions? Thanks in advance.

EDIT: attached entire ViewController rather than snippet of code.

EDIT2: Answer by k8mil was close as his answer didnt load the initial URL. Below is the only adjustment from his answer:

private func createWebView() {
guard let url = NSURL(string: "http://communionchapelefca.org/app-home") else { return }
let frame = UIScreen.mainScreen().bounds // or different frame created using CGRectMake(x,y,width,height)
self.webView = WKWebView(frame: frame)
self.webView.navigationDelegate = self
self.webView.loadRequest(NSURLRequest(URL: url))
self.view.addSubview(self.webView)
}

Answer

Try to call webView.goBack() method on your WKWebView instance instead WKWebView.goBack(). Also after goBack() you can call a webView.reload() method to make sure you're on the correct page.

I edited your code a bit

import UIKit
import WebKit

class ViewController: UIViewController, WKNavigationDelegate {

private var webView: WKWebView!

override func viewDidLoad() {
    super.viewDidLoad()
    guard let url = NSURL(string: "http://communionchapelefca.org/app-home") else {
        return
    }

    //create WebView and Back button
    createWebView()
    backButton()


    prefButton()


    NSNotificationCenter.defaultCenter().addObserver(self,
            selector: "receiveNotification:",
            name: "BeaconServiceRegionEnter",
            object: nil)

    NSNotificationCenter.defaultCenter().addObserver(self,
            selector: "receiveNotification:",
            name: "BeaconServiceRegionUpdate",
            object: nil)

    NSNotificationCenter.defaultCenter().addObserver(self,
            selector: "receiveNotification:",
            name: "BeaconServiceRegionExit",
            object: nil)

}


private func createWebView() {
    let frame  = UIScreen.mainScreen().bounds // or different frame created using CGRectMake(x,y,width,height)
    self.webView = WKWebView(frame: frame)
    self.webView.navigationDelegate = self
    self.view.addSubview(self.webView)
}

func addBackButton(text: String, action: Selector) {
    //this function will add Button on your navigation bar e

    let rightButton = UIBarButtonItem(title: text, style: .Plain, target: self, action: action)
    self.navigationItem.rightBarButtonItem = rightButton
}


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

func prefButton() {
    let image = UIImage(named: "icon-pref128") as UIImage?
    let button = UIButton(type: UIButtonType.Custom) as UIButton
    let screenSize: CGRect = UIScreen.mainScreen().bounds
    let screenWidth = screenSize.width
    let screenHeight = screenSize.height

    button.frame = CGRectMake(screenWidth * 0.85, screenHeight * 0.90, 56, 56) // (X, Y, Height, Width)
    button.setImage(image, forState: .Normal)
    button.addTarget(self, action: "buttonClicked:", forControlEvents: .TouchUpInside)
    self.view.addSubview(button)
}

func backButton() {
    let image = UIImage(named: "icon-back") as UIImage?
    let button = UIButton(type: UIButtonType.Custom) as UIButton
    let screenSize: CGRect = UIScreen.mainScreen().bounds
    let screenWidth = screenSize.width
    let screenHeight = screenSize.height

    button.frame = CGRectMake(screenWidth * 0.85, screenHeight * 0.90, 56, 56) // (X, Y, Height, Width)
    button.setImage(image, forState: .Normal)
    button.addTarget(self, action: "customGoBack:", forControlEvents: .TouchUpInside)
    self.view.addSubview(button)
}

func customGoBack(sender: UIButton) {
    if self.webView.canGoBack {
        print("Can go back")
        self.webView.goBack()
        self.webView.reload()
    } else {
        print("Can't go back")
    }
}

func buttonClicked(sender: UIButton) {
    UIApplication.sharedApplication().openURL(NSURL(string: UIApplicationOpenSettingsURLString)!)
}

func receiveNotification(notification: NSNotification) {
    print(notification.userInfo)
}

func webView(webView: WKWebView, decidePolicyForNavigationAction navigationAction: WKNavigationAction, decisionHandler: (WKNavigationActionPolicy) -> Void) {
    if navigationAction.navigationType == .LinkActivated {
        if let newURL = navigationAction.request.URL,
        host = newURL.host where !host.containsString("communionchapelefca.org") &&
                UIApplication.sharedApplication().canOpenURL(newURL) {
            if UIApplication.sharedApplication().openURL(newURL) {
                print(newURL)
                print("Redirected to browser. No need to open it locally")
                decisionHandler(.Cancel)
            } else {
                print("browser can not url. allow it to open locally")
                decisionHandler(.Allow)
            }
        } else {
            print("Open it locally")
            decisionHandler(.Allow)
        }
    } else {
        print("not a user click")
        decisionHandler(.Allow)
    }
}

}

Also you don't neeed another instance of WKWebView because you have declared previously in :

private var webView : WKWebView!

so it is not necessary :

wv.navigationDelegate = self
wv.loadRequest(NSURLRequest(URL: url))  
view.addSubview(wv)

For me it works.

Hope this will help you :)