add bridge base

Author: Lision

WKWebViewJavascriptBridge/WKWebViewJavascriptBridgeBase.swift

@@ -7,3 +7,160 @@
 //
 
 import Foundation
+
+@available(iOS 9.0, *)
+protocol WKWebViewJavascriptBridgeBaseDelegate: AnyObject {
+    func evaluateJavascript(javascript: String)
+}
+
+@available(iOS 9.0, *)
+class WKWebViewJavascriptBridgeBase: NSObject {
+    typealias Callback = (_ responseData: Any?) -> Void
+    typealias Handler = (_ parameters: [String: Any]?, _ callback: Callback?) -> Void
+    typealias Message = [String: Any]
+    
+    weak var delegate: WKWebViewJavascriptBridgeBaseDelegate?
+    var startupMessageQueue = [Message]()
+    var responseCallbacks = [String: Callback]()
+    var messageHandlers = [String: Handler]()
+    var uniqueId = 0
+    
+    override init() {
+        super.init()
+    }
+    
+    func reset() {
+        self.startupMessageQueue = [Message]()
+        self.responseCallbacks = [String: Callback]()
+        self.uniqueId = 0
+    }
+    
+    func send(data: Any?, callback: Callback?, handlerName: String?) {
+        var message = [String: Any]()
+        
+        if data != nil {
+            message["data"] = data
+        }
+        
+        if callback != nil {
+            self.uniqueId += 1
+            let callbackID = "native_iOS_cb_\(self.uniqueId)"
+            self.responseCallbacks[callbackID] = callback
+            message["callbackID"] = callbackID
+        }
+        
+        if handlerName != nil {
+            message["handlerName"] = handlerName
+        }
+        
+        self.queue(message: message)
+    }
+    
+    func flush(messageQueueString: String) {
+        guard let messages = self.deserialize(messageJSON: messageQueueString) else {
+            log(messageQueueString)
+            return
+        }
+        
+        for message in messages {
+            log(message)
+            
+            if let responseID = message["responseID"] as? String {
+                let callback = self.responseCallbacks[responseID]
+                callback!(message["responseData"]!)
+                self.responseCallbacks.removeValue(forKey: responseID)
+            } else {
+                var callback: Callback?
+                if let callbackID = message["callbackID"] {
+                    callback = { (_ responseData: Any?) -> Void in
+                        guard responseData != nil else {
+                            return
+                        }
+                        
+                        let msg = ["responseID": callbackID, "responseData": responseData!] as Message
+                        self.queue(message: msg)
+                    }
+                } else {
+                    callback = { (_ responseData: Any?) -> Void in
+                        // no logic
+                    }
+                }
+                
+                guard let handlerName = message["handlerName"] as? String else {
+                    return
+                }
+                guard let handler = self.messageHandlers[handlerName] else {
+                    log("NoHandlerException, No handler for message from JS: \(message)")
+                    return
+                }
+                handler(message["data"] as? [String : Any], callback)
+            }
+        }
+    }
+    
+    // MARK: - Private
+    fileprivate func queue(message: Message) {
+        if self.startupMessageQueue.isEmpty {
+            self.dispatch(message: message)
+        } else {
+            self.startupMessageQueue.append(message)
+        }
+    }
+    
+    fileprivate func dispatch(message: Message) {
+        guard var messageJSON = self.serialize(message: message, pretty: false) else {
+            return
+        }
+        
+        messageJSON = messageJSON.replacingOccurrences(of: "\\", with: "\\\\")
+        messageJSON = messageJSON.replacingOccurrences(of: "\"", with: "\\\"")
+        messageJSON = messageJSON.replacingOccurrences(of: "\'", with: "\\\'")
+        messageJSON = messageJSON.replacingOccurrences(of: "\n", with: "\\n")
+        messageJSON = messageJSON.replacingOccurrences(of: "\r", with: "\\r")
+//        messageJSON = messageJSON.replacingOccurrences(of: "\f", with: "\\f")
+//        messageJSON = messageJSON.replacingOccurrences(of: "\u2028", with: "\\u2028")
+//        messageJSON = messageJSON.replacingOccurrences(of: "\u2029", with: "\\u2029")
+        
+        let javascriptCommand = "WebViewJavascriptBridge._handleMessageFromObjC('\(messageJSON)');"
+        if Thread.current.isMainThread {
+            self.delegate?.evaluateJavascript(javascript: javascriptCommand)
+        } else {
+            DispatchQueue.main.async {
+                self.delegate?.evaluateJavascript(javascript: javascriptCommand)
+            }
+        }
+    }
+    
+    // MARK: - JSON
+    fileprivate func serialize(message: Message, pretty: Bool) -> String? {
+        var result: String?
+        do {
+            let data = try JSONSerialization.data(withJSONObject: message, options: pretty ? .prettyPrinted : JSONSerialization.WritingOptions(rawValue: 0))
+            result = String(data: data, encoding: .utf8)!
+        } catch let error {
+            log(error)
+        }
+        return result
+    }
+    
+    fileprivate func deserialize(messageJSON: String) -> [Message]? {
+        var result = [Message]()
+        guard let data = messageJSON.data(using: .utf8) else {
+            return nil
+        }
+        do {
+            result = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as! [WKWebViewJavascriptBridgeBase.Message]
+        } catch let error {
+            log(error)
+        }
+        return result
+    }
+    
+    // MARK: - Log
+    fileprivate func log<T>(_ message: T, file: String = #file, function: String = #function, line: Int = #line) {
+        #if DEBUG
+            let fileName = (file as NSString).lastPathComponent
+            print("\(fileName):\(line) \(function) | \(message)")
+        #endif
+    }
+}