[webview_flutter] Expose loadData function for webviews

Author: Geert-Johan Riemer

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

@@ -122,6 +122,9 @@ public void onMethodCall(MethodCall methodCall, Result result) {
       case "loadUrl":
         loadUrl(methodCall, result);
         break;
+      case "loadData":
+        loadData(methodCall, result);
+        break;
       case "updateSettings":
         updateSettings(methodCall, result);
         break;
@@ -175,6 +178,18 @@ private void loadUrl(MethodCall methodCall, Result result) {
     result.success(null);
   }
 
+  @SuppressWarnings("unchecked")
+  private void loadData(MethodCall methodCall, Result result) {
+    Map<String, Object> request = (Map<String, Object>) methodCall.arguments;
+    String baseUrl = (String) request.get("baseUrl");
+    String data = (String) request.get("data");
+    String mimeType = (String) request.get("mimeType");
+    String encoding = (String) request.get("encoding");
+    webView.loadDataWithBaseURL(baseUrl, data, mimeType, encoding, "");
+    result.success(null);
+  }
+
+
   private void canGoBack(Result result) {
     result.success(webView.canGoBack());
   }

packages/webview_flutter/ios/Classes/FlutterWebView.m

@@ -128,6 +128,8 @@ - (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:@"loadData"]) {
+    [self onLoadData:call result:result];
   } else if ([[call method] isEqualToString:@"canGoBack"]) {
     [self onCanGoBack:call result:result];
   } else if ([[call method] isEqualToString:@"canGoForward"]) {
@@ -175,6 +177,17 @@ - (void)onLoadUrl:(FlutterMethodCall*)call result:(FlutterResult)result {
   }
 }
 
+- (void)onLoadData:(FlutterMethodCall*)call result:(FlutterResult)result {
+  if (![self loadData:[call arguments]]) {
+    result([FlutterError
+        errorWithCode:@"loadData_failed"
+              message:@"Failed parsing the data"
+              details:[NSString stringWithFormat:@"Request was: '%@'", [call arguments]]]);
+  } else {
+    result(nil);
+  }
+}
+
 - (void)onCanGoBack:(FlutterMethodCall*)call result:(FlutterResult)result {
   BOOL canGoBack = [_webView canGoBack];
   result([NSNumber numberWithBool:canGoBack]);
@@ -374,6 +387,20 @@ - (bool)loadUrl:(NSString*)url withHeaders:(NSDictionary<NSString*, NSString*>*)
   return true;
 }
 
+- (bool)loadData:(NSDictionary<NSString*, id>*)request {
+  if (!request) {
+    return false;
+  }
+
+  NSString* data = request[@"data"];
+  NSString* baseUrl = request[@"baseUrl"];
+  NSString* mimeType = request[@"mimeType"];
+  NSString* encoding = request[@"encoding"];
+  NSData* nsData = [data dataUsingEncoding:NSUTF8StringEncoding];
+  NSURL* nsUrl = [NSURL URLWithString:baseUrl];
+  return [_webView loadData:nsData MIMEType:mimeType characterEncodingName:encoding baseURL:nsUrl];
+}
+
 - (void)registerJavaScriptChannels:(NSSet*)channelNames
                         controller:(WKUserContentController*)userContentController {
   for (NSString* channelName in channelNames) {

packages/webview_flutter/lib/platform_interface.dart

@@ -64,6 +64,16 @@ abstract class WebViewPlatformController {
         "WebView loadUrl is not implemented on the current platform");
   }
 
+  Future<void> loadData(
+    String baseUrl,
+    String data,
+    String mimeType,
+    String encoding
+  ) {
+    throw UnimplementedError(
+        "WebView loadData 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

@@ -60,6 +60,22 @@ class MethodChannelWebViewPlatform implements WebViewPlatformController {
     });
   }
 
+      @override
+  Future<void> loadData(
+    String baseUrl,
+    String data,
+    String mimeType,
+    String encoding
+  ) async {
+    print("loadData call");
+    return _channel.invokeMethod<void>('loadData', <String, dynamic>{
+      'baseUrl': baseUrl,
+      'data': data,
+      'mimeType': mimeType,
+      'encoding': encoding,
+    });
+  }
+
   @override
   Future<String> currentUrl() => _channel.invokeMethod<String>('currentUrl');
 

packages/webview_flutter/lib/webview_flutter.dart

@@ -531,6 +531,14 @@ class WebViewController {
     return _webViewPlatformController.loadUrl(url, headers);
   }
 
+  Future<void> loadData(
+    String baseUrl, 
+    String data,
+    String mimeType,
+    String encoding) async {
+    return _webViewPlatformController.loadData(baseUrl, data, mimeType, encoding);
+  }
+
   /// Accessor to the current URL that the WebView is displaying.
   ///
   /// If [WebView.initialUrl] was never specified, returns `null`.