fixed issue with headers in javascript code for intercepting ajax requests

android/src/main/java/com/pichillilorenzo/flutter_inappbrowser/InAppWebView/InAppWebView.java

@@ -146,10 +146,12 @@ final public class InAppWebView extends InputAwareWebView {
           "    this._flutter_inappbrowser_isAsync = isAsync;" +
           "    this._flutter_inappbrowser_user = user;" +
           "    this._flutter_inappbrowser_password = password;" +
+          "    this._flutter_inappbrowser_request_headers = {};" +
           "    open.call(this, method, url, isAsync, user, password);" +
           "  };" +
           "  ajax.prototype.setRequestHeader = function(header, value) {" +
           "    this._flutter_inappbrowser_request_headers[header] = value;" +
+          "    setRequestHeader.call(this, header, value);" +
           "  };" +
           "  function handleEvent(e) {" +
           "    var self = this;" +
@@ -290,10 +292,12 @@ final public class InAppWebView extends InputAwareWebView {
           "          };" +
           "          for (var header in result.headers) {" +
           "            var value = result.headers[header];" +
+          "            var flutter_inappbrowser_value = self._flutter_inappbrowser_request_headers[header];" +
+          "            if (flutter_inappbrowser_value == null) {" +
           "              self._flutter_inappbrowser_request_headers[header] = value;" +
-          "          };" +
-          "          for (var header in self._flutter_inappbrowser_request_headers) {" +
-          "            var value = self._flutter_inappbrowser_request_headers[header];" +
+          "            } else {" +
+          "              self._flutter_inappbrowser_request_headers[header] += ', ' + value;" +
+          "            }" +
           "            setRequestHeader.call(self, header, value);" +
           "          };" +
           "          if ((self._flutter_inappbrowser_method != result.method && result.method != null) || (self._flutter_inappbrowser_url != result.url && result.url != null)) {" +

android/src/main/java/com/pichillilorenzo/flutter_inappbrowser/JavaScriptBridgeInterface.java

@@ -39,7 +39,7 @@ public class JavaScriptBridgeInterface {
   }
 
   @JavascriptInterface
-  public void _callHandler(String handlerName, final String _callHandlerID, String args) {
+  public void _callHandler(final String handlerName, final String _callHandlerID, String args) {
     final Map<String, Object> obj = new HashMap<>();
     if (inAppBrowserActivity != null)
       obj.put("uuid", inAppBrowserActivity.uuid);
@@ -62,10 +62,10 @@ public class JavaScriptBridgeInterface {
               return;
             }
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
-              webView.evaluateJavascript("window." + name + "[" + _callHandlerID + "](" + json + "); delete window." + name + "[" + _callHandlerID + "];", (ValueCallback<String>) null);
+              webView.evaluateJavascript("if(window." + name + "[" + _callHandlerID + "] != null) {window." + name + "[" + _callHandlerID + "](" + json + "); delete window." + name + "[" + _callHandlerID + "];}", (ValueCallback<String>) null);
             }
             else {
-              webView.loadUrl("javascript:window." + name + "[" + _callHandlerID + "](" + json + "); delete window." + name + "[" + _callHandlerID + "];");
+              webView.loadUrl("javascript:if(window." + name + "[" + _callHandlerID + "] != null) {window." + name + "[" + _callHandlerID + "](" + json + "); delete window." + name + "[" + _callHandlerID + "];}");
             }
           }
 

ios/Classes/InAppWebView.swift

@@ -296,10 +296,12 @@ let interceptAjaxRequestsJS = """
     this._flutter_inappbrowser_isAsync = isAsync;
     this._flutter_inappbrowser_user = user;
     this._flutter_inappbrowser_password = password;
+    this._flutter_inappbrowser_request_headers = {};
     open.call(this, method, url, isAsync, user, password);
   };
   ajax.prototype.setRequestHeader = function(header, value) {
     this._flutter_inappbrowser_request_headers[header] = value;
+    setRequestHeader.call(this, header, value);
   };
   function handleEvent(e) {
     var self = this;
@@ -440,10 +442,12 @@ let interceptAjaxRequestsJS = """
           };
           for (var header in result.headers) {
             var value = result.headers[header];
+            var flutter_inappbrowser_value = self._flutter_inappbrowser_request_headers[header];
+            if (flutter_inappbrowser_value == null) {
               self._flutter_inappbrowser_request_headers[header] = value;
-          };
-          for (var header in self._flutter_inappbrowser_request_headers) {
-            var value = self._flutter_inappbrowser_request_headers[header];
+            } else {
+              self._flutter_inappbrowser_request_headers[header] += ', ' + value;
+            }
             setRequestHeader.call(self, header, value);
           };
           if ((self._flutter_inappbrowser_method != result.method && result.method != null) || (self._flutter_inappbrowser_url != result.url && result.url != null)) {
@@ -2021,7 +2025,7 @@ public class InAppWebView: WKWebView, UIScrollViewDelegate, WKUIDelegate, WKNavi
                     if let r = result {
                         json = r as! String
                     }
-                    self.evaluateJavaScript("window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)](\(json)); delete window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)];", completionHandler: nil)
+                    self.evaluateJavaScript("if(window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)] != null) {window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)](\(json)); delete window.\(JAVASCRIPT_BRIDGE_NAME)[\(_callHandlerID)];}", completionHandler: nil)
                 }
             })
         }

lib/src/in_app_webview.dart

@@ -591,7 +591,7 @@ class InAppWebViewController {
             String user = argMap["user"];
             String password = argMap["password"];
             bool withCredentials = argMap["withCredentials"];
-            Map<dynamic, dynamic> headers = argMap["headers"];
+            AjaxRequestHeaders headers = AjaxRequestHeaders(argMap["headers"]);
             String responseType = argMap["responseType"];
 
             var request = new AjaxRequest(data: data, method: method, url: url, isAsync: isAsync, user: user, password: password, withCredentials: withCredentials, headers: headers, responseType: responseType);
@@ -610,7 +610,7 @@ class InAppWebViewController {
             String user = argMap["user"];
             String password = argMap["password"];
             bool withCredentials = argMap["withCredentials"];
-            Map<dynamic, dynamic> headers = argMap["headers"];
+            AjaxRequestHeaders headers = AjaxRequestHeaders(argMap["headers"]);
             int readyState = argMap["readyState"];
             int status = argMap["status"];
             String responseURL = argMap["responseURL"];
@@ -639,7 +639,7 @@ class InAppWebViewController {
             String user = argMap["user"];
             String password = argMap["password"];
             bool withCredentials = argMap["withCredentials"];
-            Map<dynamic, dynamic> headers = argMap["headers"];
+            AjaxRequestHeaders headers = AjaxRequestHeaders(argMap["headers"]);
             int readyState = argMap["readyState"];
             int status = argMap["status"];
             String responseURL = argMap["responseURL"];

lib/src/types.dart

@@ -1064,6 +1064,31 @@ class AjaxRequestReadyState {
   int get hashCode => _value.hashCode;
 }
 
+///AjaxRequestHeaders class represents the HTTP headers of an [AjaxRequest].
+class AjaxRequestHeaders {
+  Map<dynamic, dynamic> _headers;
+  Map<String, dynamic> _newHeaders = {};
+
+  AjaxRequestHeaders(this._headers);
+
+  ///Gets the HTTP headers of the [AjaxRequest].
+  Map<dynamic, dynamic> getHeaders() {
+    return this._headers;
+  }
+
+  ///Sets/updates an HTTP header of the [AjaxRequest]. If there is already an existing [header] with the same name, the values are merged into one single request header.
+  ///For security reasons, some headers can only be controlled by the user agent.
+  ///These headers include the [forbidden header names](https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_header_name)
+  ///and [forbidden response header names](https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_response_header_name).
+  void setRequestHeader(String header, String value) {
+    _newHeaders[header] = value;
+  }
+
+  Map<String, dynamic> toMap() {
+    return _newHeaders;
+  }
+}
+
 ///AjaxRequest class represents a JavaScript [XMLHttpRequest](https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest) object.
 class AjaxRequest {
   ///Data passed as a parameter to the `XMLHttpRequest.send()` method.
@@ -1084,7 +1109,7 @@ class AjaxRequest {
   ///In addition, this flag is also used to indicate when cookies are to be ignored in the response. The default is false.
   bool withCredentials;
   ///The HTTP request headers.
-  Map<dynamic, dynamic> headers;
+  AjaxRequestHeaders headers;
   ///The state of the `XMLHttpRequest` request.
   AjaxRequestReadyState readyState;
   ///The numerical HTTP [status code](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status) of the `XMLHttpRequest`'s response.
@@ -1128,7 +1153,7 @@ class AjaxRequest {
       "user": user,
       "password": password,
       "withCredentials": withCredentials,
-      "headers": headers,
+      "headers": headers?.toMap(),
       "readyState": readyState?.toValue(),
       "status": status,
       "responseURL": responseURL,