goForward and goBack does not work in swiftui - xcode

Question

I am trying to add the back and forward button in the swiftui but the buttons do not work. The URL comes from a firebase.
I followed this question How to access goBack and goForward via UIViewRepresentable. If anyone help me, I am very thankful to you.
Here is the source code
import SwiftUI
import WebKit
import Firebase
struct WebView: View {
#State var websiteURL: String
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
var body: some View {
ZStack{
Color.init(red: 172/255, green: 198/255, blue: 224/255).edgesIgnoringSafeArea(.all)
VStack{
Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
Image("back").renderingMode(.original).frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: 60, alignment: .leading).padding()
}
Webview(web: nil, req: URLRequest(url: URL(string: websiteURL)!))
HStack{
Button(action: {
//go to back
Webview(web: nil, req: URLRequest(url: URL(string: websiteURL)!)).goBack()
}) {
Image(systemName: "arrow.left").foregroundColor(.black)
}
Spacer()
Button(action: {
// go forwared
Webview(web: nil, req: URLRequest(url: URL(string: websiteURL)!)).goForward()
}) {
Image(systemName: "arrow.right").foregroundColor(.black)
}
}.padding([.leading,.trailing],20)
}.navigationBarTitle("")
.navigationBarHidden(true)
}.onAppear{
self.loadURL()
}
}
func loadURL(){
//For Admin
let rootRef = Database.database().reference().child("Admin").child(websiteURL)
rootRef.observeSingleEvent(of: .value, with: { (snapshot) in
// Get user value
let value = snapshot.value as? NSDictionary
let getURL:String = value?["value"] as? String ?? ""
self.websiteURL=getURL
// ...
}) { (error) in
print(error.localizedDescription)
}
}
}
struct Webview : UIViewRepresentable {
let request: URLRequest
var webview: WKWebView?
init(web: WKWebView?, req: URLRequest) {
self.webview = WKWebView()
self.request = req
}
func makeUIView(context: Context) -> WKWebView {
return webview!
}
func updateUIView(_ uiView: WKWebView, context: Context) {
uiView.load(request)
}
func goBack(){
webview?.goBack()
}
func goForward(){
webview?.goForward()
}
}
struct WebView_Previews: PreviewProvider {
static var previews: some View {
WebView(websiteURL: "")
}
}

Answer 1

I stand by my comment, you create 3 different Webview. This is one way to make it work.
Copy and paste this code and let me know if that works for you.
import SwiftUI
import WebKit
import Firebase
struct WebView: View {
#State var websiteURL: String
#Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
let websiteView = Webview()
var body: some View {
ZStack{
Color.init(red: 172/255, green: 198/255, blue: 224/255).edgesIgnoringSafeArea(.all)
VStack{
Button(action: {
self.presentationMode.wrappedValue.dismiss()
}) {
Image("back").renderingMode(.original).frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: 60, alignment: .leading).padding()
}
self.websiteView
HStack{
Button(action: {
// go to back
self.websiteView.webview.goBack()
}) {
Image(systemName: "arrow.left").foregroundColor(.black)
}
Spacer()
Button(action: {
// go forwared
self.websiteView.webview.goForward()
}) {
Image(systemName: "arrow.right").foregroundColor(.black)
}
}.padding([.leading,.trailing],20)
}.navigationBarTitle("")
.navigationBarHidden(true)
}.onAppear{
self.loadURL()
}
}
func loadURL() {
//For Admin
let rootRef = Database.database().reference().child("Admin").child(websiteURL)
rootRef.observeSingleEvent(of: .value, with: { (snapshot) in
// Get user value
let value = snapshot.value as? NSDictionary
let getURL:String = value?["value"] as? String ?? ""
self.websiteURL = getURL
// new code <-----
self.websiteView.loadRequest(request: URLRequest(url: URL(string: self.websiteURL)!))
// ...
}) { (error) in
print(error.localizedDescription)
}
}
}
struct Webview : UIViewRepresentable {
#State var request: URLRequest?
let webview = WKWebView()
func makeUIView(context: Context) -> WKWebView {
return webview
}
func updateUIView(_ uiView: WKWebView, context: Context) {
if request != nil { uiView.load(request!) }
}
func loadRequest(request: URLRequest) {
self.request = request
webview.load(request)
}
func goBack(){
webview.goBack()
}
func goForward(){
webview.goForward()
}
}