fluttercommunity · panuavakul · Jan 24, 2019
diff --git a/android/src/main/java/com/flutter_webview_plugin/FlutterWebviewPlugin.java b/android/src/main/java/com/flutter_webview_plugin/FlutterWebviewPlugin.java
@@ -97,6 +97,8 @@ private void openUrl(MethodCall call, MethodChannel.Result result) {
         Map<String, String> headers = call.argument("headers");
         boolean scrollBar = call.argument("scrollBar");
         boolean allowFileURLs = call.argument("allowFileURLs");
+        boolean isPost = call.argument("isPost");
+        Map<String, Object> body = call.argument("body");
 
         if (webViewManager == null || webViewManager.closed == true) {
             webViewManager = new WebviewManager(activity);
@@ -118,7 +120,9 @@ private void openUrl(MethodCall call, MethodChannel.Result result) {
                 scrollBar,
                 supportMultipleWindows,
                 appCacheEnabled,
-                allowFileURLs
+                allowFileURLs,
+                isPost,
+                body
         );
         result.success(null);
     }

diff --git a/android/src/main/java/com/flutter_webview_plugin/WebviewManager.java b/android/src/main/java/com/flutter_webview_plugin/WebviewManager.java
@@ -16,6 +16,18 @@
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
 import android.widget.FrameLayout;
+import android.os.AsyncTask;
+
+import java.io.InputStreamReader;
+import java.net.URL;
+import java.net.HttpURLConnection;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.BufferedReader;
+import java.io.DataOutputStream;
+
+import 	org.json.JSONObject;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -204,7 +216,9 @@ void openUrl(
             boolean scrollBar,
             boolean supportMultipleWindows,
             boolean appCacheEnabled,
-            boolean allowFileURLs
+            boolean allowFileURLs,
+            boolean isPost,
+            Map<String, Object> body
     ) {
         webView.getSettings().setJavaScriptEnabled(withJavascript);
         webView.getSettings().setBuiltInZoomControls(withZoom);
@@ -243,13 +257,38 @@ void openUrl(
             webView.setVerticalScrollBarEnabled(false);
         }
 
-        if (headers != null) {
-            webView.loadUrl(url, headers);
+        if (isPost && body != null) {
+            PostUrlTask task = new PostUrlTask();
+            task.setListener(createPostUrlTaskListener(url));
+
+            PostUrlInput input = new PostUrlInput(url, headers, body, userAgent);
+
+            task.execute(input);
+
         } else {
-            webView.loadUrl(url);
+            if (headers != null) {
+                webView.loadUrl(url, headers);
+            } else {
+                webView.loadUrl(url);
+            }
         }
     }
 
+    /// Helper method for creating the listener for the Post Url task
+    private PostUrlTask.Listener createPostUrlTaskListener(String url) {
+        final String urlString = url;
+        return new PostUrlTask.Listener() {
+            @Override
+            public void onSuccess(PostUrlResult result) {
+                if (result.responseStatus == "HTTP_OK") {
+                    webView.loadDataWithBaseURL(urlString, result.htmlResult, "text/html", "utf-8", null);
+                } else {
+                    // Do nothing for now // Show error page?
+                }
+            }
+        };
+    }
+
     void reloadUrl(String url) {
         webView.loadUrl(url);
     }
@@ -340,3 +379,157 @@ void stopLoading(MethodCall call, MethodChannel.Result result){
         }
     }
 }
+
+
+class PostUrlInput {
+    PostUrlInput(
+        String urlString,
+        Map<String, String> headers,
+        Map<String, Object> body,
+        String userAgent
+    ){
+        this.urlString = urlString;
+        this.headers = headers;
+        this.body = body;
+        this.userAgent = userAgent;
+    }
+
+    String urlString;
+    Map<String, String> headers;
+    Map<String, Object> body;
+    String userAgent;
+}
+
+class PostUrlResult {
+    PostUrlResult(String responseStatus, String htmlResult) {
+        this.responseStatus = responseStatus;
+        this.htmlResult = htmlResult;
+    }
+
+    String responseStatus;
+    String htmlResult;
+}
+
+// Since Android WebView does not support loading POST with
+// custom header, this class is used to get the html needed
+// to make a POST request and show the response to WebView
+class PostUrlTask extends AsyncTask<PostUrlInput, Void, PostUrlResult> {
+
+    private Listener listener;
+
+    @Override
+    protected PostUrlResult doInBackground(PostUrlInput... params) {
+
+        HttpURLConnection httpConn = null;
+        String responseStatus = null;
+        String htmlResult = "";
+        PostUrlInput input = params[0];
+
+        try {
+            URL url = new URL(input.urlString);
+
+            // HttpURLConnection
+            httpConn = (HttpURLConnection) url.openConnection();
+
+            // request POST
+            httpConn.setRequestMethod("POST");
+
+            // no Redirects
+            httpConn.setInstanceFollowRedirects(false);
+
+            httpConn.setDoOutput(true);
+
+            // Set headers
+            if (input.headers != null){
+                for (Map.Entry<String, String> header : input.headers.entrySet()){
+                    httpConn.setRequestProperty(header.getKey(), header.getValue());
+                }
+            }
+
+            // Set user agent
+            if(input.userAgent != null) {
+                httpConn.setRequestProperty("User-Agent", input.userAgent);
+            }
+
+            httpConn.setReadTimeout(10000);
+            httpConn.setConnectTimeout(20000);
+
+            httpConn.connect();
+
+            OutputStream outStream = null;
+
+            try {
+                outStream = new DataOutputStream(httpConn.getOutputStream ());
+
+                JSONObject bodyJson = new JSONObject(input.body);
+
+                outStream = httpConn.getOutputStream();
+                outStream.write( bodyJson.toString().getBytes("UTF-8"));
+
+                outStream.flush();
+
+                Log.d("debug","flush");
+            } catch (IOException e) {
+                e.printStackTrace();
+                responseStatus = "POST_ERROR";
+            } finally {
+                if (outStream != null) {
+                    outStream.close();
+                }
+            }
+
+            final int status = httpConn.getResponseCode();
+
+            if (status == HttpURLConnection.HTTP_OK) {
+                responseStatus = "HTTP_OK";
+
+                // Get the html here
+                InputStream stream = httpConn.getInputStream();
+                StringBuffer stringBuffer = new StringBuffer();
+                String line;
+                BufferedReader br = new BufferedReader(new InputStreamReader(stream, "UTF-8"));
+                while ((line = br.readLine()) != null) {
+                    stringBuffer.append(line);
+                }
+
+                try {
+                    stream.close();
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+
+                htmlResult = stringBuffer.toString();
+            }
+            else{
+                responseStatus = "STATUS="+String.valueOf(status);
+            }
+
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            if (httpConn != null) {
+                httpConn.disconnect();
+            }
+        }
+
+        PostUrlResult result = new PostUrlResult(responseStatus, htmlResult);
+        return result;
+    }
+
+    @Override
+    protected void onPostExecute(PostUrlResult result) {
+        super.onPostExecute(result);
+
+        if (listener != null) {
+            listener.onSuccess(result);
+        }
+    }
+
+    void setListener(Listener listener) {
+        this.listener = listener;
+    }
+
+    interface Listener {
+        void onSuccess(PostUrlResult result);
+    }
+}
diff --git a/ios/Classes/FlutterWebviewPlugin.m b/ios/Classes/FlutterWebviewPlugin.m
@@ -137,6 +137,7 @@ - (void)navigate:(FlutterMethodCall*)call {
     if (self.webview != nil) {
             NSString *url = call.arguments[@"url"];
             NSNumber *withLocalUrl = call.arguments[@"withLocalUrl"];
+            NSNumber *isPost = call.arguments[@"isPost"];
             if ( [withLocalUrl boolValue]) {
                 NSURL *htmlUrl = [NSURL fileURLWithPath:url isDirectory:false];
                 if (@available(iOS 9.0, *)) {
@@ -152,6 +153,27 @@ - (void)navigate:(FlutterMethodCall*)call {
                     [request setAllHTTPHeaderFields:headers];
                 }
 
+                if (isPost != nil) {
+                    if ([isPost boolValue]) {
+                        /// If this is a post request then set the method and body
+                        [request setHTTPMethod:@"POST"];
+
+                        NSDictionary *body = call.arguments[@"body"];
+
+                        NSError *error = nil;
+                        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:body
+                                                                options:NSJSONWritingPrettyPrinted
+                                                                error:&error];
+
+                        /// Check if there is an error
+                        if (!jsonData) {
+                            NSLog(@"Error parsing JSON %@", error);
+                        } else {
+                            [request setHTTPBody:jsonData];
+                        }
+                    }
+                }
+
                 [self.webview loadRequest:request];
             }
         }

diff --git a/lib/src/base.dart b/lib/src/base.dart
@@ -101,6 +101,8 @@ class FlutterWebviewPlugin {
     bool clearCookies,
     bool hidden,
     bool enableAppScheme,
+    bool isPost,
+    Map<String, dynamic> body,
     Rect rect,
     String userAgent,
     bool withZoom,
@@ -118,6 +120,7 @@ class FlutterWebviewPlugin {
       'hidden': hidden ?? false,
       'clearCookies': clearCookies ?? false,
       'enableAppScheme': enableAppScheme ?? true,
+      'isPost': isPost ?? false,
       'userAgent': userAgent,
       'withZoom': withZoom ?? false,
       'withLocalStorage': withLocalStorage ?? true,
@@ -132,6 +135,10 @@ class FlutterWebviewPlugin {
       args['headers'] = headers;
     }
 
+    if (isPost != false && body != null) {
+      args['body'] = body;
+    }
+
     if (rect != null) {
       args['rect'] = {
         'left': rect.left,

diff --git a/lib/src/webview_scaffold.dart b/lib/src/webview_scaffold.dart
@@ -17,6 +17,8 @@ class WebviewScaffold extends StatefulWidget {
     this.clearCache,
     this.clearCookies,
     this.enableAppScheme,
+    this.isPost,
+    this.body,
     this.userAgent,
     this.primary = true,
     this.persistentFooterButtons,
@@ -39,6 +41,8 @@ class WebviewScaffold extends StatefulWidget {
   final bool clearCache;
   final bool clearCookies;
   final bool enableAppScheme;
+  final bool isPost;
+  final Map<String, dynamic> body;
   final String userAgent;
   final bool primary;
   final List<Widget> persistentFooterButtons;
@@ -106,6 +110,8 @@ class _WebviewScaffoldState extends State<WebviewScaffold> {
               clearCookies: widget.clearCookies,
               hidden: widget.hidden,
               enableAppScheme: widget.enableAppScheme,
+              isPost: widget.isPost,
+              body: widget.body,
               userAgent: widget.userAgent,
               rect: _rect,
               withZoom: widget.withZoom,