Applying changes by flutter#1247 and adapting them to work with webview_flutter 0.3.9 (iOS code: not tested)

Author: Andrei Bosco

packages/webview_flutter/ios/Classes/FlutterWebView.h

@@ -12,13 +12,13 @@ NS_ASSUME_NONNULL_BEGIN
 - (instancetype)initWithFrame:(CGRect)frame
                viewIdentifier:(int64_t)viewId
                     arguments:(id _Nullable)args
-              binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger;
+                    registrar:(NSObject<FlutterPluginRegistrar>*)registrar;
 
 - (UIView*)view;
 @end
 
 @interface FLTWebViewFactory : NSObject <FlutterPlatformViewFactory>
-- (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger;
+- (instancetype)initWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar;
 @end
 
 NS_ASSUME_NONNULL_END

packages/webview_flutter/ios/Classes/FlutterWebView.m

@@ -7,13 +7,14 @@
 #import "JavaScriptChannelHandler.h"
 
 @implementation FLTWebViewFactory {
-  NSObject<FlutterBinaryMessenger>* _messenger;
+  NSObject<FlutterPluginRegistrar>* _registrar;
 }
 
-- (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {
+- (instancetype)initWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
   self = [super init];
   if (self) {
-    _messenger = messenger;
+    _registrar = registrar;
+    _messenger = registrar.messenger;
   }
   return self;
 }
@@ -28,7 +29,7 @@ - (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {
   FLTWebViewController* webviewController = [[FLTWebViewController alloc] initWithFrame:frame
                                                                          viewIdentifier:viewId
                                                                               arguments:args
-                                                                        binaryMessenger:_messenger];
+                                                                              registrar:_registrar];
   return webviewController;
 }
 
@@ -42,17 +43,20 @@ @implementation FLTWebViewController {
   // The set of registered JavaScript channel names.
   NSMutableSet* _javaScriptChannelNames;
   FLTWKNavigationDelegate* _navigationDelegate;
+  NSObject<FlutterPluginRegistrar>* _registrar;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame
                viewIdentifier:(int64_t)viewId
                     arguments:(id _Nullable)args
-              binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {
+                    registrar:(NSObject<FlutterPluginRegistrar>*)registrar {
   if ([super init]) {
     _viewId = viewId;
+    _registrar = registrar;
 
     NSString* channelName = [NSString stringWithFormat:@"plugins.flutter.io/webview_%lld", viewId];
-    _channel = [FlutterMethodChannel methodChannelWithName:channelName binaryMessenger:messenger];
+    _channel = [FlutterMethodChannel methodChannelWithName:channelName
+                                           binaryMessenger:registrar.messenger];
     _javaScriptChannelNames = [[NSMutableSet alloc] init];
 
     WKUserContentController* userContentController = [[WKUserContentController alloc] init];
@@ -77,7 +81,11 @@ - (instancetype)initWithFrame:(CGRect)frame
 
     NSString* initialUrl = args[@"initialUrl"];
     if ([initialUrl isKindOfClass:[NSString class]]) {
-      [self loadUrl:initialUrl];
+      if ([initialUrl rangeOfString:@"://"].location == NSNotFound) {
+        [self loadAssetFile:initialUrl];
+      } else {
+        [self loadUrl:initialUrl];
+      }
     }
   }
   return self;
@@ -92,6 +100,8 @@ - (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:@"loadAssetFile"]) {
+    [self onLoadAssetFile:call result:result];
   } else if ([[call method] isEqualToString:@"canGoBack"]) {
     [self onCanGoBack:call result:result];
   } else if ([[call method] isEqualToString:@"canGoForward"]) {
@@ -133,6 +143,17 @@ - (void)onLoadUrl:(FlutterMethodCall*)call result:(FlutterResult)result {
   }
 }
 
+- (void)onLoadAssetFile:(FlutterMethodCall*)call result:(FlutterResult)result {
+  NSString* url = [call arguments];
+  if (![self loadAssetFile:url]) {
+    result([FlutterError errorWithCode:@"loadAssetFile_failed"
+                               message:@"Failed parsing the URL"
+                               details:[NSString stringWithFormat:@"URL was: '%@'", url]]);
+  } else {
+    result(nil);
+  }
+}
+
 - (void)onCanGoBack:(FlutterMethodCall*)call result:(FlutterResult)result {
   BOOL canGoBack = [_webView canGoBack];
   result([NSNumber numberWithBool:canGoBack]);
@@ -289,6 +310,20 @@ - (bool)loadUrl:(NSString*)url withHeaders:(NSDictionary<NSString*, NSString*>*)
   return true;
 }
 
+- (bool)loadAssetFile:(NSString*)url {
+  NSString* key = [_registrar lookupKeyForAsset:url];
+  NSURL* nsUrl = [[NSBundle mainBundle] URLForResource:key withExtension:nil];
+  if (!nsUrl) {
+    return false;
+  }
+  if (@available(iOS 9.0, *)) {
+    [_webView loadFileURL:nsUrl allowingReadAccessToURL:[NSURL URLWithString:@"file:///"]];
+  } else {
+    return false;
+  }
+  return true;
+}
+
 - (void)registerJavaScriptChannels:(NSSet*)channelNames
                         controller:(WKUserContentController*)userContentController {
   for (NSString* channelName in channelNames) {

packages/webview_flutter/ios/Classes/WebViewFlutterPlugin.m

@@ -5,8 +5,7 @@
 @implementation FLTWebViewFlutterPlugin
 
 + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
-  FLTWebViewFactory* webviewFactory =
-      [[FLTWebViewFactory alloc] initWithMessenger:registrar.messenger];
+  FLTWebViewFactory* webviewFactory = [[FLTWebViewFactory alloc] initWithRegistrar:registrar];
   [registrar registerViewFactory:webviewFactory withId:@"plugins.flutter.io/webview"];
   [FLTCookieManager registerWithRegistrar:registrar];
 }