I know how to pass data from javascript to swift, but don't know how to pass data from swift to javascript.
The method i use to pass data from javascript to swift is below:
<head>
<title>Test</title>
<meta charset="UTF-8">
</head>
<body>
<h1>WebView Test 3</h1>
<script>
function callNativeApp () {
try {
webkit.messageHandlers.callbackHandler.postMessage("Here");
} catch(err) {
console.log('The native context does not exist yet');
}
}
callNativeApp();
</script>
</body>
import UIKit
import WebKit
class ThirdViewController: UIViewController,WKScriptMessageHandler{
override func viewDidLoad() {
super.viewDidLoad()
let configuration=WKWebViewConfiguration()
let controller=WKUserContentController()
controller.addScriptMessageHandler(self, name: "callbackHandler")
configuration.userContentController=controller
let webView=WKWebView(frame: self.view.frame, configuration: configuration)
let url=NSBundle.mainBundle().URLForResource("test3", withExtension: "html")
let request=NSURLRequest(URL: url!)
self.view=webView
webView.loadRequest(request)
}
func userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) {
if(message.name == "callbackHandler"){
print("callbackHandler: \(message.body)")
}
}
}
I know how to pass data from javascript to swift, but don't know how to pass data from swift to javascript.
The method i use to pass data from javascript to swift is below:
<head>
<title>Test</title>
<meta charset="UTF-8">
</head>
<body>
<h1>WebView Test 3</h1>
<script>
function callNativeApp () {
try {
webkit.messageHandlers.callbackHandler.postMessage("Here");
} catch(err) {
console.log('The native context does not exist yet');
}
}
callNativeApp();
</script>
</body>
import UIKit
import WebKit
class ThirdViewController: UIViewController,WKScriptMessageHandler{
override func viewDidLoad() {
super.viewDidLoad()
let configuration=WKWebViewConfiguration()
let controller=WKUserContentController()
controller.addScriptMessageHandler(self, name: "callbackHandler")
configuration.userContentController=controller
let webView=WKWebView(frame: self.view.frame, configuration: configuration)
let url=NSBundle.mainBundle().URLForResource("test3", withExtension: "html")
let request=NSURLRequest(URL: url!)
self.view=webView
webView.loadRequest(request)
}
func userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) {
if(message.name == "callbackHandler"){
print("callbackHandler: \(message.body)")
}
}
}
2 Answers
Reset to default 5As you know, you pass information to Swift by calling postMessage.
To pass information to the browser from Swift you just call evaluateJavascript like so:
let num1 = 4
let num2 = 8
webView.evaluateJavaScript("addTwoNumbers(\(num1), \(num2);") { (result, error) in
guard error == nil else {
print("there was an error")
return
}
print(Int(result))
}
For this particular code to do anything you would need a addTwoNumbers function in the Javascript that handled the function and done something.
As an example I'll take a JS function like this :-
function send_message(val01, val02) {
// you JS CODE
}
Then to run the function you should call :-
self.webView.stringByEvaluatingJavaScriptFromString("send_message(\"\(self.value1)\", \"\(self.value2)\")")!