fix bridge leaks

Author: Lision

WKWebViewJavascriptBridge/WKWebViewJavascriptBridge.swift

@@ -20,12 +20,16 @@ public class WKWebViewJavascriptBridge: NSObject {
  public init(webView: WKWebView) {
  super.init()
  self.webView = webView
- self.webView?.configuration.userContentController.add(self, name: iOS_Native_InjectJavascript)
- self.webView?.configuration.userContentController.add(self, name: iOS_Native_FlushMessageQueue)
  base = WKWebViewJavascriptBridgeBase()
  base.delegate = self
+ addScriptMessageHandlers()
  }
 
+ deinit {
+ removeScriptMessageHandlers()
+ }
+ 
+ // MARK: - Public Funcs
  public func reset() {
  base.reset()
  }
@@ -42,7 +46,8 @@ public class WKWebViewJavascriptBridge: NSObject {
  base.send(handlerName: handlerName, data: data, callback: callback)
  }
 
- func flushMessageQueue() {
+ // MARK: - Private Funcs
+ private func flushMessageQueue() {
  webView?.evaluateJavaScript("WKWebViewJavascriptBridge._fetchQueue();") { (result, error) in
  if error != nil {
  print("WKWebViewJavascriptBridge: WARNING: Error when trying to fetch data from WKWebView: \(String(describing: error))")
@@ -52,6 +57,16 @@ public class WKWebViewJavascriptBridge: NSObject {
  self.base.flush(messageQueueString: resultStr)
  }
  }
+ 
+ private func addScriptMessageHandlers() {
+ webView?.configuration.userContentController.add(LeakAvoider(delegate: self), name: iOS_Native_InjectJavascript)
+ webView?.configuration.userContentController.add(LeakAvoider(delegate: self), name: iOS_Native_FlushMessageQueue)
+ }
+ 
+ private func removeScriptMessageHandlers() {
+ webView?.configuration.userContentController.removeScriptMessageHandler(forName: iOS_Native_InjectJavascript)
+ webView?.configuration.userContentController.removeScriptMessageHandler(forName: iOS_Native_FlushMessageQueue)
+ }
 }
 
 extension WKWebViewJavascriptBridge: WKWebViewJavascriptBridgeBaseDelegate {
@@ -71,3 +86,18 @@ extension WKWebViewJavascriptBridge: WKScriptMessageHandler {
  }
  }
 }
+
+class LeakAvoider: NSObject {
+ weak var delegate: WKScriptMessageHandler?
+ 
+ init(delegate: WKScriptMessageHandler) {
+ super.init()
+ self.delegate = delegate
+ }
+}
+
+extension LeakAvoider: WKScriptMessageHandler {
+ func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
+ delegate?.userContentController(userContentController, didReceive: message)
+ }
+}

WKWebViewJavascriptBridge/WKWebViewJavascriptBridgeBase.swift

@@ -8,7 +8,6 @@
 
 import Foundation
 
-@available(iOS 9.0, *)
 protocol WKWebViewJavascriptBridgeBaseDelegate: AnyObject {
  func evaluateJavascript(javascript: String)
 }