I am using Xcode 8.3.3 and Swift 3 to develop an app for the iMac using Cocoa. My goal is to use VCgoToWebPage and display a webpage to the user. My program calls this function many times, but the only webpage I see is the last one called. How do I implement a window refresh inside this function and wait for the webpage to be fully rendered?
func VCgoToWebPage(theWebPage : String) {
let url = URL(string: theWebPage)!
let request = URLRequest(url: url)
webView.load(request)
/*The modal box allows the web pages to be seen. Without it, after a series of calls to VCgoToWebPage only the last page called is displayed. The modal box code is just for debugging and will be removed. */
let alert = NSAlert()
alert.messageText="calling EDGAR page"
alert.informativeText=theWebPage
alert.addButton(withTitle: "OK")
alert.runModal()
}
You can use navigation delegate to make sure navigation to a page is complete before trying to load another. Have your class conform to WKNavigationDelegate and set webView.navigationDelegate to that class instance.
var allRequests = [URLRequest]()
func VCgoToWebPage(theWebPage : String) {
guard let url = URL(string: theWebPage) else {
return
}
let request = URLRequest(url: url)
if webView.isLoading{
allRequests.append(request)
} else {
webView.load(request)
}
}
func webView(WKWebView, didFinish: WKNavigation!){
if let nextRequest = allRequests.first{
webView.load(nextRequest)
allRequests.removeFirst()
}
}
Related
I am using WKWebView to render several (around 100) web pages that I then need to render to PDF. I am using the createPDF method of WKWebView to accomplish this. The reason I'm doing each individual page in its own web view is because createPDF doesn't respect page breaks in the HTML (as far as I know).
So I have a class where I start the loop to render each page:
class PrintVC: ViewController, WKNavigationDelegate {
var pages = [Page]()
func start(){
//A "page" is a struct that has the string content to load each web view
for page in pages{
let webView = WKWebView()
webView.navigationDelegate = self
webView.loadHTMLString(page.content, baseURL: Bundle.main.bundleURL)
}
}
}
I know the page is ready to be saved to PDF in the didFinish navigation delegate method:
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
let config = WKPDFConfiguration()
config.rect = CGRect(x: 0, y: 0, width: 792, height: 612)
//Create the PDF
webView.createPDF(configuration: config){ result in
switch result{
case .success(let data):
do{
try data.write(to: URL(fileURLWithPath: "file-???.pdf"))
}catch let error{
print(error)
}
case .failure(let error):
print(error)
}
}
}
}
The trouble I'm having is I don't know when each individual page is done rendering. I also don't know how to pass each page's name to be used in the file path to save it.
How can I start a bunch of WKWebView loads and know when they are all done? Or better still, how can I reuse the same WKWebView and load each individual page in the same way? I assume using the same web view would be a better use of memory.
How can I start a bunch of WKWebView loads and know when they are all done?
Well, you'd need to identify which web view caused the delegate method to be called. It is for this reason that the first parameter - webView: WKWebView - exists.
One way is to put each (web view, pair) into a dictionary ([WKWebView: Page]). Then start the loading:
// assume you have declared a property "self.webViewDict"
for page in pages{
let webView = WKWebView()
webView.navigationDelegate = self
self.webViewDict[webView] = page
webView.loadHTMLString(page.content, baseURL: Bundle.main.bundleURL)
}
When one finishes loading, you can identify the page by doing webViewDict[webView]. You should then remove the web view from the dictionary:
webViewDict[webView] = nil
if webViewDict.isEmpty {
// everything is loaded!
}
how can I reuse the same WKWebView and load each individual page in the same way?
Note that if you use the same WKWebView, you'll have to load the pages sequentially. The same web view can't load multiple things at the same time.
You can just removed the loaded pages from pages. If you don't want to do that, you can copy pages to another var first.
In start, load the first page:
if let firstPage = pages.first {
webView.loadHTMLString(firstPage.content, baseURL: Bundle.main.bundleURL)
}
When you successfully load a page, do the same thing again:
case .success(let data):
pages.removeFirst()
if let firstPage = pages.first {
webView.loadHTMLString(firstPage.content, baseURL: Bundle.main.bundleURL)
} else {
// we are done!
}
I have an array of Google News article urls. Google News article urls redirect immediately to real urls, ie: CNBC.com/.... I am trying to pull out the real, redirected url. I thought I could loop through the list and load the Google News link in a WebView, then call webView.url in a DispatchQueue after 1 second to get the real url, but this doesn't work.
How could you fetch a list of redirected urls quickly?
Here's my code you could use to reproduce the problem:
let webView = WKWebView()
let myList = [URL(string: "https://news.google.com/articles/CAIiEDthIxbgofssGWTpXgeJXzwqGQgEKhAIACoHCAow2Nb3CjDivdcCMJ_d7gU?hl=en-US&gl=US&ceid=US%3Aen"), URL(string: "https://news.google.com/articles/CAIiEP5m1nAOPt-LIA4IWMOdB3MqGQgEKhAIACoHCAowocv1CjCSptoCMPrTpgU?hl=en-US&gl=US&ceid=US%3Aen")]
for url in myList {
guard let link = url else {continue}
self.webView.loadUrl(string: link.absoluteString)
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
let redirectedLink = self.webView.url
print("HERE redirected url: ", redirectedLink) // this does not work
}
}
There are two problems with your attempt:
1) You're using one and the same web view in the loop and since nothing inside the loop blocks until the web view has finished loading, you just end up cancelling the previous request with every loop pass.
2) Even if you did block inside the loop, accessing the URL after a second won't work reliably since the navigation could easily take longer than that.
What I would recommend doing is to continue using a single web view (to save resources) but to use its navigation delegate interface for resolving the URLs one by one.
This is a crude example to give you a basic idea:
import UIKit
import WebKit
#objc class RedirectResolver: NSObject, WKNavigationDelegate {
private var urls: [URL]
private var resolvedURLs = [URL]()
private let completion: ([URL]) -> Void
private let webView = WKWebView()
init(urls: [URL], completion: #escaping ([URL]) -> Void) {
self.urls = urls
self.completion = completion
super.init()
webView.navigationDelegate = self
}
func start() {
resolveNext()
}
private func resolveNext() {
guard let url = urls.popLast() else {
completion(resolvedURLs)
return
}
let request = URLRequest(url: url)
webView.load(request)
}
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
resolvedURLs.append(webView.url!)
resolveNext()
}
}
class ViewController: UIViewController {
private var resolver: RedirectResolver!
override func viewDidLoad() {
super.viewDidLoad()
resolver = RedirectResolver(
urls: [URL(string: "https://news.google.com/articles/CAIiEDthIxbgofssGWTpXgeJXzwqGQgEKhAIACoHCAow2Nb3CjDivdcCMJ_d7gU?hl=en-US&gl=US&ceid=US%3Aen")!, URL(string: "https://news.google.com/articles/CAIiEP5m1nAOPt-LIA4IWMOdB3MqGQgEKhAIACoHCAowocv1CjCSptoCMPrTpgU?hl=en-US&gl=US&ceid=US%3Aen")!],
completion: { urls in
print(urls)
})
resolver.start()
}
}
This outputs the following resolved URLs:
[https://amp.cnn.com/cnn/2020/04/09/politics/trump-coronavirus-tests/index.html, https://www.cnbc.com/amp/2020/04/10/asia-markets-coronavirus-china-inflation-data-currencies-in-focus.html]
One other thing to note is that the redirection of those URLs in particular seems to rely on JavaScript which means you indeed need a web view. Otherwise kicking off URLRequests manually and observing the responses would have been enough.
I'm getting info from an API using the following function where I pass in a string of a word. Sometimes the word doesn't available in the API if it doesn't available I generate a new word and try that one.
The problem is because this is an asynchronous function when I launch the page where the value from the API appears it is sometimes empty because the function is still running in the background trying to generate a word that exists in the API.
How can I make sure the page launches only when the data been received from the api ?
static func wordDefin (word : String, completion: #escaping (_ def: String )->(String)) {
let wordEncoded = word.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)
let uri = URL(string:"https://dictapi.lexicala.com/search?source=global&language=he&morph=false&text=" + wordEncoded! )
if let unwrappedURL = uri {
var request = URLRequest(url: unwrappedURL);request.addValue("Basic bmV0YXlhbWluOk5ldGF5YW1pbjg5Kg==", forHTTPHeaderField: "Authorization")
let dataTask = URLSession.shared.dataTask(with: request) { (data, response, error) in
do {
if let data = data {
let decoder = JSONDecoder()
let empty = try decoder.decode(Empty.self, from: data)
if (empty.results?.isEmpty)!{
print("oops looks like the word :" + word)
game.wordsList.removeAll(where: { ($0) == game.word })
game.floffWords.removeAll(where: { ($0) == game.word })
helper.newGame()
} else {
let definition = empty.results?[0].senses?[0].definition
_ = completion(definition ?? "test")
return
}
}
}
catch {
print("connection")
print(error)
}
}
dataTask.resume()
}
}
You can't stop a view controller from "launching" itself (except not to push/present/show it at all). Once you push/present/show it, its lifecycle cannot—and should not—be stopped. Therefore, it's your responsibility to load the appropriate UI for the "loading state", which may be a blank view controller with a loading spinner. You can do this however you want, including loading the full UI with .isHidden = true set for all view objects. The idea is to do as much pre-loading of the UI as possible while the database is working in the background so that when the data is ready, you can display the full UI with as little work as possible.
What I'd suggest is after you've loaded the UI in its "loading" configuration, download the data as the final step in your flow and use a completion handler to finish the task:
override func viewDidLoad() {
super.viewDidLoad()
loadData { (result) in
// load full UI
}
}
Your data method may look something like this:
private func loadData(completion: #escaping (_ result: Result) -> Void) {
...
}
EDIT
Consider creating a data manager that operates along the following lines. Because the data manager is a class (a reference type), when you pass it forward to other view controllers, they all point to the same instance of the manager. Therefore, changes that any of the view controllers make to it are seen by the other view controllers. That means when you push a new view controller and it's time to update a label, access it from the data property. And if it's not ready, wait for the data manager to notify the view controller when it is ready.
class GameDataManager {
// stores game properties
// updates game properties
// does all thing game data
var score = 0
var word: String?
}
class MainViewController: UIViewController {
let data = GameDataManager()
override func viewDidLoad() {
super.viewDidLoad()
// when you push to another view controller, point it to the data manager
let someVC = SomeOtherViewController()
someVC.data = data
}
}
class SomeOtherViewController: UIViewController {
var data: GameDataManager?
override func viewDidLoad() {
super.viewDidLoad()
if let word = data?.word {
print(word)
}
}
}
class AnyViewController: UIViewController {
var data: GameDataManager?
}
I've been trying to figure out how to integrate an ASWebAuthenticationSession (to perform login via Oauth) with SwiftUI. I can't find any documentation on the same online anywhere and was wondering if someone with more SwiftUI and iOS dev experience could tell me how I can achieve something along the lines. I currently need a system for someone to click the Login button which then opens a ASWebAuthSession and allows the user to login before redirecting them back to my app and loading another SwiftUI view.
I have in my ContentView one button whos calls this function :
func getAuthTokenWithWebLogin() {
let authURL = URL(string: "https://test-login.blabla.no/connect/authorize?scope=openid%20profile%20AppFramework%20offline_access&response_type=code&client_id=<blalblalba>&redirect_uri=https://integration-partner/post-login")
let callbackUrlScheme = "no.blabla:/oauthdirect"
webAuthSession = ASWebAuthenticationSession.init(url: authURL!, callbackURLScheme: callbackUrlScheme, completionHandler: { (callBack:URL?, error:Error?) in
// handle auth response
guard error == nil, let successURL = callBack else {
return
}
let oauthToken = NSURLComponents(string: (successURL.absoluteString))?.queryItems?.filter({$0.name == "code"}).first
// Do what you now that you've got the token, or use the callBack URL
print(oauthToken ?? "No OAuth Token")
})
// Kick it off
webAuthSession?.start()
}
But I get this error:
Cannot start ASWebAuthenticationSession without providing presentation
context. Set presentationContextProvider before calling -start.
How should I do this in SwiftUI? Any examples would be fantastic!
With .webAuthenticationSession(isPresented:content) modifier in BetterSafariView, you can easily use ASWebAuthenticationSession in SwiftUI. It handles the work related to providing presentation context.
import SwiftUI
import BetterSafariView
struct ContentView: View {
#State private var startingWebAuthenticationSession = false
var body: some View {
Button("Start WebAuthenticationSession") {
self.startingWebAuthenticationSession = true
}
.webAuthenticationSession(isPresented: $startingWebAuthenticationSession) {
WebAuthenticationSession(
url: URL(string: "https://github.com/login/oauth/authorize?client_id=\(clientID)")!,
callbackURLScheme: "myapp"
) { callbackURL, error in
print(callbackURL, error)
}
}
}
}
As written in the subject, I would like to redirect the user to my App when he's using share extensions. For example when he tries to share a photo through my app - he opens the images, clicks on share, selects my app and then he is redirected to the app. He is in fact, but when he is, the app opens and then instantly closes. I made the solution in reference to this:
https://kitefaster.com/2016/07/13/how-to-open-ios-app-with-custom-url/
(adding all the necessary stuff in plist)
And in Share Extensions I made the following function:
func redirectToApp() {
let urlString = "myAppName://"
let url = NSURL(string: urlString)
let selectorOpenURL = sel_registerName("openURL:")
let context = NSExtensionContext()
context.open(url! as URL, completionHandler: nil)
var responder = self as UIResponder?
while (responder != nil) {
if responder?.responds(to: selectorOpenURL) == true {
responder?.perform(selectorOpenURL, with: url)
}
responder = responder!.next
}
}