WKJavaScriptController

Calling native code from Javascript in iOS likes JavascriptInterface in Android.

Requirements

• Xcode 11.4+
• Swift 5.2+
• iOS8+

(based on WKJavaScriptController 2.1.0+)

Installation with Swift Package Manager

Add the following to your Package.swift:

dependencies:[
// ...
.package(url:"https://github.com/ridi/WKJavaScriptController.git"),]

Usage

import WKJavaScriptController
// Create protocol.
// '@objc' keyword is required. because method call is based on ObjC.
@objcprotocolJavaScriptInterface{func onSubmit(_ dictonary:[String:AnyObject])func onSubmit(_ email:String, firstName:String, lastName:String, address1:String, address2:String, zipCode:JSInt, phoneNumber:String)func onCancel()varisSubmitted:JSBool{get}@objcoptionalfunc getErrorMessages(codes:[JSInt])->[String]}
// Implement protocol. extensionViewController:JavaScriptInterface{func onSubmit(_ dictonary:[String:AnyObject]){NSLog("onSubmit \(dictonary)")}func onSubmit(_ email:String, firstName:String, lastName:String, address1:String, address2:String, zipCode:JSInt, phoneNumber:String){NSLog("onSubmit \(email), \(firstName), \(lastName), \(address1), \(address2), \(zipCode.value), \(phoneNumber)")}func onCancel(){NSLog("onCancel")}varisSubmitted:JSBool{returnJSBool(true)}func getErrorMessages(codes:[JSInt])->[String]{return codes.map{"message\($0)"}}}classViewController:UIViewController{overridefunc viewDidAppear(_ animated:Bool){
super.viewDidAppear(animated)
// Create javaScriptController.
letjavaScriptController=WKJavaScriptController(name:"native", target:self, bridgeProtocol:JavaScriptInterface.self)
// [Optional] Add your javascript.
letconfiguration=WKWebViewConfiguration()letjsCode=...letuserScript=WKUserScript(source: jsCode, injectionTime:.AtDocumentEnd, forMainFrameOnly:true)
userContentController.addUserScript(userScript)
configuration.userContentController = userContentController
// Create WKWebView instance.
webView =WKWebView(frame: view.frame, configuration: configuration)
// Assign javaScriptController.
webView.javaScriptController = javaScriptController
// Call prepareForJavaScriptController before initializing WKWebView or loading page.
webView.prepareForJavaScriptController()
webView.loadRequest(...)}...}

// In javascript.native.onSubmit({'first_name': 'Davin','last_name': 'Ahn','mail': 'davin.ahn@ridi.com',});

Can receive native return in JavaScript as Promise:

// In javascript.constisSubmitted=awaitnative.isSubmitted;// or native.isSubmitted.then(isSubmitted => ...);constmessages=awaitnative.getErrorMessages([200,400,500]);// or native.getErrorMessages([200, 400, 500]).then(messages => ...);

Limitations

• Can not receive native return in JavaScript as sync. can only async return.
• Method argument length is up to 10.
• Allowed argument types are String, Date, Array, Dictionary, JSBool, JSInt, JSFloat, NSNumber and NSNull(when undefined or null passed from JavaScript).
• If Swift value types(Bool, Int32, Int, Float, Double, ...) used in argument, it must be replaced with JSBool, JSInt or JSFloat. (Because Swift value type is replaced by NSNumber in ObjC.)
• Class methods in protocol are not supported.

License

MIT