[webview_flutter] Webiew post url support

packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebView.java

@@ -18,12 +18,15 @@
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
 import io.flutter.plugin.common.MethodChannel.Result;
 import io.flutter.plugin.platform.PlatformView;
+import java.io.UnsupportedEncodingException;
+import java.net.URLEncoder;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
 public class FlutterWebView implements PlatformView, MethodCallHandler {
   private static final String JS_CHANNEL_NAMES_FIELD = "javascriptChannelNames";
+  private static final String TAG = "FlutterWebView";
   private final InputAwareWebView webView;
   private final MethodChannel methodChannel;
   private final FlutterWebViewClient flutterWebViewClient;
@@ -121,6 +124,9 @@ public void onMethodCall(MethodCall methodCall, Result result) {
       case "loadUrl":
         loadUrl(methodCall, result);
         break;
+      case "postUrl":
+        postUrl(methodCall, result);
+        break;
       case "updateSettings":
         updateSettings(methodCall, result);
         break;
@@ -162,6 +168,20 @@ public void onMethodCall(MethodCall methodCall, Result result) {
     }
   }
 
+  private static String initialParametersToString(Map<String, Object> parameters)
+      throws UnsupportedEncodingException {
+    StringBuilder sb = new StringBuilder();
+    for (Map.Entry<String, Object> entry : parameters.entrySet()) {
+      sb.append(
+          URLEncoder.encode(entry.getKey(), "UTF-8")
+              + "="
+              + URLEncoder.encode(entry.getValue().toString(), "UTF-8")
+              + "&");
+    }
+
+    return sb.deleteCharAt(sb.length() - 1).toString();
+  }
+
   @SuppressWarnings("unchecked")
   private void loadUrl(MethodCall methodCall, Result result) {
     Map<String, Object> request = (Map<String, Object>) methodCall.arguments;
@@ -174,6 +194,18 @@ private void loadUrl(MethodCall methodCall, Result result) {
     result.success(null);
   }
 
+  @SuppressWarnings("unchecked")
+  private void postUrl(MethodCall methodCall, Result result) {
+    Map<String, Object> request = (Map<String, Object>) methodCall.arguments;
+    String url = (String) request.get("url");
+
+    byte[] params = (byte[]) request.get("params");
+
+    webView.postUrl(url, params);
+
+    result.success(null);
+  }
+
   private void canGoBack(Result result) {
     result.success(webView.canGoBack());
   }

packages/webview_flutter/ios/Classes/FlutterWebView.m

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #import "FlutterWebView.h"
+#import <os/log.h>
 #import "FLTWKNavigationDelegate.h"
 #import "JavaScriptChannelHandler.h"
 
@@ -98,6 +99,8 @@ - (void)onMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
     [self onUpdateSettings:call result:result];
   } else if ([[call method] isEqualToString:@"loadUrl"]) {
     [self onLoadUrl:call result:result];
+  } else if ([[call method] isEqualToString:@"postUrl"]) {
+    [self postUrl:call result:result];
   } else if ([[call method] isEqualToString:@"canGoBack"]) {
     [self onCanGoBack:call result:result];
   } else if ([[call method] isEqualToString:@"canGoForward"]) {
@@ -340,6 +343,29 @@ - (bool)loadUrl:(NSString*)url withHeaders:(NSDictionary<NSString*, NSString*>*)
   return true;
 }
 
+- (bool)postUrl:(FlutterMethodCall*)call result:(FlutterResult)result {
+  NSDictionary<NSString*, NSObject*>* args = [call arguments];
+
+  NSString* url = (NSString*)args[@"url"];
+  NSURL* nsUrl = [NSURL URLWithString:url];
+  if (!nsUrl) {
+    return false;
+  }
+
+  NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:nsUrl];
+  FlutterStandardTypedData* postData = (FlutterStandardTypedData*)args[@"params"];
+  NSString* contentLength = @(postData.data.length).stringValue;
+
+  [request setHTTPMethod:@"POST"];
+  [request setHTTPBody:postData.data];
+
+  [request setValue:contentLength forHTTPHeaderField:@"Content-Length"];
+  [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
+
+  [_webView loadRequest:request];
+  return true;
+}
+
 - (void)registerJavaScriptChannels:(NSSet*)channelNames
                         controller:(WKUserContentController*)userContentController {
   for (NSString* channelName in channelNames) {

packages/webview_flutter/lib/platform_interface.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:typed_data';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
@@ -61,6 +62,18 @@ abstract class WebViewPlatformController {
         "WebView loadUrl is not implemented on the current platform");
   }
 
+  /// Post to the specified URL.
+  ///
+  /// `url` must not be null
+  /// `params` must not be null
+  ///
+  /// `params` have to be ascii encoded
+  /// Throws an ArgumentError if `url` is not a valid URL string.
+  Future<void> postUrl(String url, Uint8List params) {
+    throw UnimplementedError(
+        "Webview postUrl is not implemented on the current platform");
+  }
+
   /// Updates the webview settings.
   ///
   /// Any non null field in `settings` will be set as the new setting value.

packages/webview_flutter/lib/src/webview_method_channel.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:typed_data';
 
 import 'package:flutter/services.dart';
 
@@ -55,6 +56,16 @@ class MethodChannelWebViewPlatform implements WebViewPlatformController {
     });
   }
 
+  @override
+  Future<void> postUrl(String url, Uint8List params) async {
+    assert(url != null);
+    assert(params != null);
+    return _channel.invokeMethod('postUrl', <String, dynamic>{
+      'url': url,
+      'params': params,
+    });
+  }
+
   @override
   Future<String> currentUrl() => _channel.invokeMethod<String>('currentUrl');
 

packages/webview_flutter/lib/webview_flutter.dart

@@ -505,6 +505,20 @@ class WebViewController {
     return _webViewPlatformController.loadUrl(url, headers);
   }
 
+  /// Post to the specified URL.
+  ///
+  /// `url` must not be null
+  /// `params` must not be null
+  ///
+  /// `params` have to be ascii encoded
+  /// Throws an ArgumentError if `url` is not a valid URL string.
+  Future<void> postUrl(String url, List<int> params) async {
+    assert(url != null);
+    assert(params != null);
+    _validateUrlString(url);
+    return _webViewPlatformController.postUrl(url, params);
+  }
+
   /// Accessor to the current URL that the WebView is displaying.
   ///
   /// If [WebView.initialUrl] was never specified, returns `null`.