Handles the agent that interacts with the user. A web view supports a complete web-browsing experience. You use WKWebView to display interactive web content in your app. The URL object is then provided to the URLRequest initializer, which then assigns a URLRequest object to the request constant. Save my name, email, and website in this browser for the next time I comment. All Rights Reserved. We send a JavaScript string to the web view. Privacy Policy WKWebView is an essential part of rendering web pages in mobile apps, but what is WKWebView? First, make sure youve set up the constraints of your web view and added an outlet of type NSLayoutConstraint for the heightConstraint of the web view itself. @abstract The frame's current request. addScriptMessageHandler/addScriptMessageHandlerWithReply will strongly hold the object, you need to removeScriptMessageHandlerForName operation at the right time, otherwise it will cause circular reference. The user script also attaches to that same clickListener handler. Responding to Navigation with WKNavigationDelegate, App Store Turns 10 in 2018: A Peek Into The Evolution of Mobile App Development, 6 Snapchat Hacks and Pro Tips to Grow Your Business, Error Handling with Try and Catch in Swift, 5 Key Steps to Apply for a Small Business Loan, 87 Instagram Ideas and Poll Questions to Catapult Engagement and Win Leads, 7 Simple Ways to Make Money Online in 2021, How Automated Customer Service Helps Scale Your Customer Support, Alexa Kid Skills Developers in UK & Germany Make It to the Amazon Developer Rewards Program, How to respond to events and user interaction with delegation, Why WKWebView is useful, and in what scenarios, Some quick tips, like getting the web page content size, Open the XIB or Storyboard you want to add the web view to in Interface Builder, Find the web view or WKWebView in the Object Library at the bottom-left of Interface Builder, Drag-and-drop a WKWebView object from the Object Library to your view controllers canvas, and adjust its size and position. Set their function bodies to print(#function), so we can see the order in which the functions are called. @property (nonatomic, readonly, getter=isMainFrame) BOOL mainFrame; /*! As you can see the WKProcessPool class does not leak any interface, which means we can only create and read the object and determine if it is in the same process by the object address. if(winScroll){ Once your code is updated to include WKWebView, you can take advantage of the additional features offered to enhance the web views of your app. Refund Policy A navigation delegate reacts when users click links in your web content or interact with your web content in any way that affects the navigation. WKScriptMessageHandler and WKScriptMessageHandlerWithReply are proxy protocols exposed by WKUserContentController and contain a must-implement method for responding to messages sent by the webs JavaScript code. Let customers reserve tables, pay bills, & find your restaurant through a restaurant mobile app. Update Policy Keep in mind that any HTML page needs and. So, lets hook into some page navigation events! so we can see the error message, You can show a network activity spinner when a page navigation starts, And stop the network activity indicator when navigation stops, You can show an alert controller dialog when errors occur, load(_:mimeType:characterEncodingName:baseURL:) and loadHTMLString(_:baseURL:) to load web pages, and HTML directly, estimatedProgress, isLoading and hasOnlySecureContent to get the state of the web page, reload() and stopLoading() to respectively reload and stop loading the page, goBack(), goForward() and go(to:) for history-based navigation, like a normal web browser, canGoBack, canGoForward and backForwardList to get information about navigation history. @property (nullable, nonatomic, copy) NSString *applicationNameForUserAgent API_AVAILABLE(macos(10.11), ios(9.0)); @interface WKProcessPool : NSObject . However, back when the very first iPhone was being designed and developed, the mobile Internet was in its infancy. btnFix.classList.remove('fixed-btn'); The above code works fine with iOS 12 and Swift 5. The navigator.userAgent is a browser property that contains the User Agent String, which is a bit of text that identifies the type/model of the browser thats loading the web page. In many ways, WKWebView is an evolution of UIWebView. Apple has already stopped accepting new apps that include the UIWebView framework. @abstract The preference settings to be used by the web view. The downside of this approach is that its only one way: you can inject JavaScript in the web page, but you cant respond to events happening in the web view from within the web view itself. The js prompt() method is used to display a dialog box for the user to make input. In the simplest terms, WKWebView allows mobile app developers to integrate mobile web content into their User Interface through the use of web views. NSHTTPURLResponse *response = (NSHTTPURLResponse *)navigationResponse.response; decisionHandler(WKNavigationResponsePolicyCancel); decisionHandler(WKNavigationResponsePolicyAllow); //Authentication Challenge:/blog/blog/137-ssl-pinning.html. JavaScript is used to code things in web browsers. The definition is as follows. This matches the height of the web page, which we subsequently use to set the heightConstraint on the web view. The above mentioned runJavaScriptTextInputPanelWithPrompt method when introducing WKUIDelegate, this method is meant to give native APP a time to realize prompt pop-up window by itself when executing prompt method, notice that this method has a completionHandler, that is, native APP will return data to JS side after processing. SPONSORED Whether it is Application Performance Monitoring, Crash Reporting or Bug Reporting, Instabug has your back. And youll need to import the WebKit framework too, at the top of your view controller: Awesome! PCT/US21/36182, |Last Updated on December 8th, 202112:00 pm|. Any URL on the web page will load relatively from your base URL. The most simple form of a web view is really bare-bones! The integration of web pages and content in modern app development projects is essential to creating a great User Experience. Unfortunately, web pages typically have a lot of moving pieces, so your mileage may vary. Unfortunately, JavaScript-based interaction between the web view and your app is interesting, to say the least. When users click a web link in your app content, the web view acts as a browser when it displays the content at the link. Heres how: Its recommended to create an outlet for the web view in your view controller class, such as: Dont forget to connect the outlet in Interface Builder! That means you can inspect elements, check the values of properties, and assign event handlers. JavaScripts alerts are blocking, which means JavaScript execution will not continue until the alert finishes. WKWebView is an API that helps render web pages in iOS and macOS apps. Minimalist Apps Are The Future. To understand the specifics of how WKWebView works, you need to understand what a web view is. And add the following function to your view controller: func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage){ print(message.body)}. Because postMessag has no callback interface, it cannot bring back the execution result of native APP. Heres a useful snippet that sets an initial viewport with, and uses iOSs default San Francisco font: And heres something else Imagine youre building your recipe app and you want to display a web view below some native views, such as an image view and a few labels.

And thats not everything, you can for example use the webView(_:decidePolicyFor:decisionHandler:) function to decide if a page navigation is allowed. WKContentWorld has two class attributes defaultClientWorld , pageWorld , which represent the JS runtime space of native APP and web container respectively. Weve looked at loading a simple web page in WKWebView and responding to navigation events. WWDC22 SALE: Save 50% on all my Swift books and bundles! Probably Apple also found this problem, so in iOS 14, there are many new optimized APIs for WKWebView, including the optimization for addScriptMessageHandler. In addition, they also told app developers that currently use UIWebView on the App Store that they need to update to WKWebView. @property (nonatomic, strong) WKProcessPool *processPool; /*! Before we really dive into this API and its power in iOS app development, lets look back to the beginning of the mobile Internet. The initial deadline that apps had to be updated by was the end of 2020. The web view is quite a powerful component, albeit tricky to work with too. String { print(userAgent) } })}Heres what happens when the web view finishes navigation: You can evaluate almost any kind of JavaScript code. ){ print(#function)}. Not quite yet. It is better than UIWebView, and soon it will be the only web view framework allowed on the App Store. We touched on this earlier in the piece. You could also create that same user interface with HTML and CSS. Chances are you have used apps that utilize a web view to deliver a quality User Experience; after all, this is a big part of modern mobile app development. WKWebView not only replaced UIWebView in UIKit but also WebView in AppKit. So, when the message My hovercraft is full of eels! gets posted to the message handler, the delegate function userContentController(_:didReceive:) gets called on your view controller. A web page and an app are two distinct environments. You should now see an error message in the Console: The resource could not be loaded because the App Transport Security policy requires the use of a secure connection.This happens because youre only allowed to load HTTPS URLs on iOS by default. A new didReceiveScriptMessage API with replyHandler has been added. }else {

Ideal for displaying HTML markup, styled text content, or complete web pages. First, make your view controller conform to it by adding WKUIDelegate to its list of protocols. Create Your App Nowwindow.addEventListener("scroll", function(){ - (void)webView:(WKWebView *)webView didFailNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error; - (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler; - (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler {, if ([navigationResponse.response isKindOfClass:[NSHTTPURLResponse class]]) {. You can, however, interact with the web view using a number of properties, objects and delegate protocols. WKWebViews with the same WKProcessPool object share the same process space. const btnFix = document.querySelector('.cstm-btn.hide.blog-btn.chat-btn.banner-btn'); This configuration object gets a WKUserScript object, which contains JavaScript code. And of course, you can load any kind of HTML and CSS in the web view. Weve provided a simple closure that prints out the userAgent constant if its a value of type String. }); Your email address will not be published. And its completely interactive, so you can navigate the web page like an ordinary browser. Turn leads into clients and prospects into sales with the help of a mobile app for your business. It is hard to remember a time before the rise of the mobile Internet. Streamlined communication between app and web page, The same powerful JavaScript engine used by Safari. And that concludes our exploration of WKWebView. Developers can use a navigation delegate to accomplish this. @abstract The frame's current security origin. WKNavigationDelegate has some important interfaces in addition to the above methods. The baseURL parameter allows you to set a base URL for the web page, like the HTML tag. 15+ years of technical experience helping over 500 clients build apps for iOS and Android with exceptional success. @property (nonatomic, strong) WKUserContentController *userContentController; /*! You want to get the content height as soon as the page has finished loading completely. Notifications can be turned off anytime from browser settings, 2021, Appy Pie. A WKWebView web view has two main delegate protocols and properties: Of these two delegate protocols, the WKNavigationDelegate is probably used most frequently. @abstract The user content controller to associate with the web view. And weve looked at different scenarios in which a web view might come in handy. For example, you can make WKWebView show a custom alert controller when any web page uses the alert() JavaScript function: Theres also runJavaScriptConfirmPanelWithMessage for showing confirm and deny UI, runJavaScriptTextInputPanelWithPrompt for requesting user text input, and so on. btnFix.classList.remove('fixed-btn'); Then the question arises: when executing postMessage on JS side, what if we get the execution result of native APP? You add these views, including the web view, in a scroll view, so the user can scroll the entire stack of views from top to bottom. Developers can also create a separate JS runtime environment by using: + (WKContentWorld *)worldWithName:(NSString *)name factory method. @property (nonatomic, readonly, copy) WKWebViewConfiguration *configuration; @property (nullable, nonatomic, weak) id navigationDelegate; @property (nullable, nonatomic, weak) id UIDelegate; @property (nonatomic, readonly, strong) WKBackForwardList *backForwardList; @property (nonatomic, readonly, nullable) SecTrustRef serverTrust; @property (nullable, nonatomic, copy) NSString *customUserAgent; @property (nonatomic) BOOL allowsLinkPreview; @property (nonatomic, readonly, strong) UIScrollView *scrollView; - (nullable WKNavigation *)loadRequest:(NSURLRequest *)request; - (nullable WKNavigation *)loadFileURL:(NSURL *)URL allowingReadAccessToURL:(NSURL *)readAccessURL; - (nullable WKNavigation *)reloadFromOrigin; + (BOOL)handlesURLScheme:(NSString *)urlScheme; - (void)evaluateJavaScript:(NSString *)javaScriptString completionHandler:(void (^ _Nullable)(_Nullable id, NSError * _Nullable error))completionHandler; - (void)evaluateJavaScript:(NSString *)javaScriptString inFrame:(nullable WKFrameInfo *)frame inContentWorld:(WKContentWorld *)contentWorld completionHandler:(void (^ _Nullable)(_Nullable id, NSError * _Nullable error))completionHandler; - (void)callAsyncJavaScript:(NSString *)functionBody arguments:(nullable NSDictionary *)arguments inFrame:(nullable WKFrameInfo *)frame inContentWorld:(WKContentWorld *)contentWorld completionHandler:(void (^ _Nullable)(_Nullable id, NSError * _Nullable error))completionHandler; - (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation; - (void)webView:(WKWebView *)webView didFinishNavigation:(null_unspecified WKNavigation *)navigation; - (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error. Developers can use a WKWebViewConfiguration object to specify parameters for custom URL schemes, media playback, interaction behaviors, customize preferences for web content, and manage cookies. The WKWebView class can be used to display interactive web content in your iOS app, much like an in-app browser. One of the best, most common examples of this concept at work is the Gmail app for iOS. This is also a big difference between WKWebView and UIWebView. The second webView(_:didCommit:) function is called when the web view starts receiving data from the web server. Second, assign your view controller to the uiDelegate property of your web view: Finally, implement whichever of the optional methods of WKUIDelegate takes your interest. This will show a bold string of text in the web view. @property (nonatomic, readonly, copy) NSURLRequest *request; /*! Stream music, and reach out to a wider audience with the help of your own radio app. You could even store the recipe HTML pages on a webserver, and update them on-the-fly. Mobile app builder to create an app in 3 steps. The crowning achievement of WebKit was WKWebView. Finally, run the app! The red thread here is that were creating an instance of WKWebView manually, and assign it a WKWebViewConfiguration object. WKUserScript represents a JavaScript script that needs to be injected into the web page. A UI delegate allows developers to present users with native User Interface elements while they are interacting with web content in a web view. JavaScript is enabled in a WKWebView by default, and you can use it to do a thousand-and-one things. [name].postMessage sometimes doesnt work well, and it doesnt work well when you need to synchronize the JS side to get the data from the native APP before you can continue executing the JS code. At present, I have not found an elegant solution for this problem, so I have two options for reference. Still, if youre launching iOS apps, you will need to migrate from UIWebView to WKWebView now because UIWebView is no longer accepted on the App Store as of April 2020. Youve got several options. Web Application: Understanding the Differences, Disruptive Technology Examples at Use Every Day, Understanding The Role Of Cyber Security When Creating Finance Apps. @property (nonatomic, strong) WKWebsiteDataStore *websiteDataStore API_AVAILABLE(macos(10.11), ios(9.0)); /*! Compared with UIWebView, WKWebView has higher performance, supports more HTML5 features and has more detailed control. func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation! >>, Paul Hudson @twostraws May 28th 2019. Users can accomplish all of this without ever leaving the Gmail app, thanks to WKWebView. - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message replyHandler:(void (^)(id _Nullable reply, NSString *_Nullable errorMessage))replyHandler; WKUserContentController *userContentController = [[WKUserContentController alloc] init]; [userContentController addScriptMessageHandler:self name:@"easeapiHandler"]; WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc] init]; configuration.userContentController = userContentController; self.webView = [[WKWebView alloc] initWithFrame:self.view.bounds configuration:configuration]; NSURLRequest *request = [[NSURLRequest alloc] initWithURL:[NSURL URLWithString:@"https://easeapi.com/blog"]]; How to package NextJs separately by server-side or browser-side type, WKScriptMessageHandler and WKScriptMessageHandlerWithReply, WKWebView and JS interaction synchronization problem, WKWebView addScriptMessageHandler circular reference. You could create the entire user interface natively, with views, buttons and labels. When the JavaScript has been evaluated, the result is provided to a completion handler. WKWebView has key performance features, including: In 2020, Apple announced that no new apps using the UIWebView framework would be accepted on the App Store. Its like having a small web browser right in your app! And vice-versa, you can create full-fledged web apps that run inside Safari on iOS. Ultimately, Apple decided to build iOS and run software like apps. Object that identifies information about the current page content. Technology protected by US Patent No. 2007 - Koombea, Inc. All Rights Reserved. At this point it will attempt to load the web page HTML, as data is coming in. } Its part of the WebKit framework and WKWebView uses the same browser engine as Safari on iOS and Mac. - (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential * _Nullable credential))completionHandler; @interface WKFrameInfo : NSObject , /*! Obviously, logically, there is a possibility of name conflict between native APP JS environment and web JS runtime environment. You have one function at your disposal: evaluateJavaScript(_:completionHandler:). There are three methods that need to be highlighted. Heres how: Next, implement the five delegate functions described earlier.

And you can respond to redirects, HTTP Authentication challenges, and use crash recovery. UIWebView was the earliest API used to render web views in iOS apps as a part of UIKit. @abstract The web view of the webpage that contains this frame.

Get the visibility you need to understand your apps performance and speed up the debugging process. App development projects had to use UIWebView for iOS apps despite the fact that it was slow, had poor memory functions, and couldnt keep up with mobile Safaris superior JavaScript and rendering capabilities. This effectively sends a message from the web page to your iOS app, and thats something we couldnt do before! @abstract The website data store to be used by the web view. The usefulness of WKWebView goes beyond displaying simple web pages in your app. - (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler; - (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler; - (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(nullable NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable result))completionHandler; @protocol WKScriptMessageHandler . After registering the unique name through addScriptMessageHandler, data can be sent in the js code by. Although the date this policy goes into effect is still up in the air after being pushed back in late 2020. With this function you can load HTML directly in the web view. @abstract The name of the application as used in the user agent string. WKNavigation object can be used to understand the loading progress of a web page. Does the iPhone run software using apps like macOS, or does it run software as web pages utilizing Safari? Use the promise asynchronous callback on the JS side to get the result. CGFloat { self.heightConstraint?.constant = height } })}). For example, you might want to prohibit users from navigating to new content until certain conditions are met. } else if (winScroll < 50){ Well do so with these delegate functions: First, lets adopt the protocol and set the webView delegate. It wasnt until 2014 and iOS 8.0 that WebKit was released. Youve inserted JavaScript into the page, with two methods, and used simple commands to navigate and inspect the web view. UIWebView has been deprecated by Apple. Mobile smartphone technology has become so ubiquitous over the last ten years that we take it for granted. Dont worry, UIWebView and WKWebView are similar in nature! If your app is still using UIWebView, now is the time to update your app to WKWebView. When the iPhone was being developed, Apple engineers were faced with a choice. This includes the ability to navigate between web pages using links, features like the forward and back button, and more of the traditional browser features that users are accustomed to. navigationDelegate of type WKNavigationDelegate, which responds to navigation events, uiDelegate of type WKUIDelegate, which responds to user interaction events, webView(_:didStartProvisionalNavigation:), webView(_:didFailProvisionalNavigation:withError:), Add the WKNavigationDelegate protocol to your view controllers class declaration, like: class WebViewController: UIViewController, WKNavigationDelegate, Set the navigationDelegate property of webView to self, before loading the web request, like: webView?.navigationDelegate = self, First, change the web page URL of the web view to http://example.com, Then, add print(error) to the two error functions. connect the constraint to the outlet so you can set its constant property, Get the inner content size of the web page, and dynamically set the height of the web view to match the height of the web page (with the constraint), Optionally, disable scrolling on the web view. Itll first read the readyState of the web page, and then itll read the offsetHeight of the document body. You now have a problem, because both the scroll view and the web view can scroll! if (winScroll > 50){ Then, add the following code to your view controller: webView.evaluateJavaScript(document.readyState, completionHandler: { result, error in, if result == nil || error != nil { return }, webView.evaluateJavaScript(document.body.offsetHeight, completionHandler: { result, error in if let height = result as? Adding a web view to your app is as simple as adding a UIView or UIButton to your view controller in Interface Builder. By default WKWebView works sort of like Safari, albeit in a single view rather than having tabs. - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message; @protocol WKScriptMessageHandlerWithReply . Create an app for users to order goods & receive it with live package tracking and auto payment on delivery. Sponsor Hacking with Swift and reach the world's largest Swift community! Web views created using WKWebView provide users with a complete browsing experience. However, Apple pushed this deadline back, and as of now, there is no new deadline for updating from UIWebView to WKWebView. A WKNavigation object will be returned when the page is loaded by methods such as loadRequest, goBack, etc. Unlike this, the evaluateJavaScript interface of native APP executing js code has a completionHandler callback to get the execution result of js on the native APP side. Is It True? Whats important is to evaluate the height of the web page as late as possible, but not later. This article briefly introduces the use of UIWebView and the synchronous interaction between JS and native APP. Lets find out! @property (nonatomic, readonly, weak) WKWebView *webView API_AVAILABLE(macos(10.13), ios(11.0)); @interface WKWebViewConfiguration : NSObject . WKWebView is also superior to UIWebView in many performance aspects as well. let winScroll = document.body.scrollTop || document.documentElement.scrollTop if let userAgent = result as? It is not fair to compare UIWebView and WKWebView. If you use the above code sample with the code youve written previously in this tutorial, make sure to disable the outlet and remove the WKWebView instance from your view controller in Interface Builder first. The WKWebView API renders a complete mobile browser experience within the app itself allowing users to interact with web content while remaining in the app. As a result, the web view resizes itself to match its inner content height. WKProcessPool represents a separate process used to manage web content, and for security and stability reasons, WKWebView allocates a separate process for each WKWebView instance (instead of using the APP process space directly).

The WKWebView component is a replacement for the legacy UIWebView component. Code of Conduct. If you click on a link within an email, you can access the links target content and navigate around it using the traditional browser features. WKWebViewConfiguration indicates the configuration information for initializing WKWebVie. When you call this function on a WKWebView instance, a string of JavaScript is sent to the web page and evaluated.

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions. This event usually coincides with the DOMContentLoaded JavaScript event, but keep in mind that webView(_:didFinish:) can also be called before the HTML DOM is ready. Now developers have access to a consistent API across the two platforms. Pulp Fiction is copyright 1994 Miramax Films. There are a number of different web view aspects that developers may want to consider customizing, and WKWebView gives them the power to do so. How do you interact with a web page in a WKWebView? Hacking with Swift is 2022 Hudson Heavy Industries. Were 100% certain weve provided a valid URL, so were using force unwrapping to unwrap the optional.