Sub6Resources · ryan-berger · Nov 22, 2020 · Oct 25, 2020
diff --git a/lib/flutter_html.dart b/lib/flutter_html.dart
@@ -3,6 +3,7 @@ library flutter_html;
 import 'package:flutter/material.dart';
 import 'package:flutter_html/html_parser.dart';
 import 'package:flutter_html/style.dart';
+import 'package:webview_flutter/webview_flutter.dart';
 
 class Html extends StatelessWidget {
   /// The `Html` widget takes HTML as input and displays a RichText
@@ -40,6 +41,7 @@ class Html extends StatelessWidget {
     this.onImageTap,
     this.blacklistedElements = const [],
     this.style,
+    this.navigationDelegateForIframe,
   }) : super(key: key);
 
   final String data;
@@ -59,6 +61,11 @@ class Html extends StatelessWidget {
   /// Fancy New Parser parameters
   final Map<String, Style> style;
 
+  /// Decides how to handle a specific navigation request in the WebView of an
+  /// Iframe. It's necessary to use the webview_flutter package inside the app
+  /// to use NavigationDelegate.
+  final NavigationDelegate navigationDelegateForIframe;
+
   @override
   Widget build(BuildContext context) {
     final double width = shrinkWrap ? null : MediaQuery.of(context).size.width;
@@ -74,6 +81,7 @@ class Html extends StatelessWidget {
         style: style,
         customRender: customRender,
         blacklistedElements: blacklistedElements,
+        navigationDelegateForIframe: navigationDelegateForIframe,
       ),
     );
   }

diff --git a/lib/html_parser.dart b/lib/html_parser.dart
@@ -11,6 +11,7 @@ import 'package:flutter_html/src/utils.dart';
 import 'package:flutter_html/style.dart';
 import 'package:html/dom.dart' as dom;
 import 'package:html/parser.dart' as htmlparser;
+import 'package:webview_flutter/webview_flutter.dart';
 
 typedef OnTap = void Function(String url);
 typedef CustomRender = Widget Function(
@@ -30,6 +31,7 @@ class HtmlParser extends StatelessWidget {
   final Map<String, Style> style;
   final Map<String, CustomRender> customRender;
   final List<String> blacklistedElements;
+  final NavigationDelegate navigationDelegateForIframe;
 
   HtmlParser({
     @required this.htmlData,
@@ -40,6 +42,7 @@ class HtmlParser extends StatelessWidget {
     this.style,
     this.customRender,
     this.blacklistedElements,
+    this.navigationDelegateForIframe,
   });
 
   @override
@@ -49,6 +52,7 @@ class HtmlParser extends StatelessWidget {
       document,
       customRender?.keys?.toList() ?? [],
       blacklistedElements,
+      navigationDelegateForIframe,
     );
     StyledElement styledTree = applyCSS(lexedTree);
     StyledElement inlineStyledTree = applyInlineStyles(styledTree);
@@ -69,7 +73,7 @@ class HtmlParser extends StatelessWidget {
     // scaling is used, but relies on https://github.com/flutter/flutter/pull/59711
     // to wrap everything when larger accessibility fonts are used.
     return StyledText(
-      textSpan: parsedTree, 
+      textSpan: parsedTree,
       style: cleanedTree.style,
       textScaleFactor: MediaQuery.of(context).textScaleFactor,
     );
@@ -90,6 +94,7 @@ class HtmlParser extends StatelessWidget {
     dom.Document html,
     List<String> customRenderTags,
     List<String> blacklistedElements,
+    NavigationDelegate navigationDelegateForIframe,
   ) {
     StyledElement tree = StyledElement(
       name: "[Tree Root]",
@@ -98,8 +103,12 @@ class HtmlParser extends StatelessWidget {
     );
 
     html.nodes.forEach((node) {
-      tree.children
-          .add(_recursiveLexer(node, customRenderTags, blacklistedElements));
+      tree.children.add(_recursiveLexer(
+        node,
+        customRenderTags,
+        blacklistedElements,
+        navigationDelegateForIframe,
+      ));
     });
 
     return tree;
@@ -113,12 +122,17 @@ class HtmlParser extends StatelessWidget {
     dom.Node node,
     List<String> customRenderTags,
     List<String> blacklistedElements,
+    NavigationDelegate navigationDelegateForIframe,
   ) {
     List<StyledElement> children = List<StyledElement>();
 
     node.nodes.forEach((childNode) {
-      children.add(
-          _recursiveLexer(childNode, customRenderTags, blacklistedElements));
+      children.add(_recursiveLexer(
+        childNode,
+        customRenderTags,
+        blacklistedElements,
+        navigationDelegateForIframe,
+      ));
     });
 
     //TODO(Sub6Resources): There's probably a more efficient way to look this up.
@@ -131,7 +145,7 @@ class HtmlParser extends StatelessWidget {
       } else if (INTERACTABLE_ELEMENTS.contains(node.localName)) {
         return parseInteractableElement(node, children);
       } else if (REPLACED_ELEMENTS.contains(node.localName)) {
-        return parseReplacedElement(node);
+        return parseReplacedElement(node, navigationDelegateForIframe);
       } else if (LAYOUT_ELEMENTS.contains(node.localName)) {
         return parseLayoutElement(node, children);
       } else if (TABLE_STYLE_ELEMENTS.contains(node.localName)) {
@@ -268,7 +282,8 @@ class HtmlParser extends StatelessWidget {
           shrinkWrap: context.parser.shrinkWrap,
           child: Stack(
             children: [
-              if (tree.style?.listStylePosition == ListStylePosition.OUTSIDE || tree.style?.listStylePosition == null)
+              if (tree.style?.listStylePosition == ListStylePosition.OUTSIDE ||
+                  tree.style?.listStylePosition == null)
                 PositionedDirectional(
                   width: 30, //TODO derive this from list padding.
                   start: 0,

diff --git a/lib/src/replaced_element.dart b/lib/src/replaced_element.dart
@@ -5,16 +5,16 @@ import 'package:chewie/chewie.dart';
 import 'package:chewie_audio/chewie_audio.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
-import 'package:flutter_html/src/utils.dart';
-import 'package:flutter_svg/flutter_svg.dart';
-import 'package:video_player/video_player.dart';
-import 'package:webview_flutter/webview_flutter.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_html/html_parser.dart';
 import 'package:flutter_html/src/html_elements.dart';
+import 'package:flutter_html/src/utils.dart';
 import 'package:flutter_html/style.dart';
+import 'package:flutter_svg/flutter_svg.dart';
 import 'package:html/dom.dart' as dom;
+import 'package:video_player/video_player.dart';
+import 'package:webview_flutter/webview_flutter.dart';
 
 /// A [ReplacedElement] is a type of [StyledElement] that does not require its [children] to be rendered.
 ///
@@ -158,6 +158,7 @@ class IframeContentElement extends ReplacedElement {
   final String src;
   final double width;
   final double height;
+  final NavigationDelegate navigationDelegate;
 
   IframeContentElement({
     String name,
@@ -166,6 +167,7 @@ class IframeContentElement extends ReplacedElement {
     this.width,
     this.height,
     dom.Element node,
+    this.navigationDelegate,
   }) : super(name: name, style: style, node: node);
 
   @override
@@ -176,6 +178,7 @@ class IframeContentElement extends ReplacedElement {
       child: WebView(
         initialUrl: src,
         javascriptMode: JavascriptMode.unrestricted,
+        navigationDelegate: navigationDelegate,
         gestureRecognizers: {
           Factory(() => PlatformViewVerticalGestureRecognizer())
         },
@@ -350,7 +353,10 @@ class RubyElement extends ReplacedElement {
   }
 }
 
-ReplacedElement parseReplacedElement(dom.Element element) {
+ReplacedElement parseReplacedElement(
+  dom.Element element,
+  NavigationDelegate navigationDelegateForIframe,
+) {
   switch (element.localName) {
     case "audio":
       final sources = <String>[
@@ -377,6 +383,7 @@ ReplacedElement parseReplacedElement(dom.Element element) {
         src: element.attributes['src'],
         width: double.tryParse(element.attributes['width'] ?? ""),
         height: double.tryParse(element.attributes['height'] ?? ""),
+        navigationDelegate: navigationDelegateForIframe,
       );
     case "img":
       return ImageContentElement(

diff --git a/test/html_parser_test.dart b/test/html_parser_test.dart
@@ -1,9 +1,9 @@
 import 'package:flutter/material.dart';
-import 'package:flutter_html/src/html_elements.dart';
+import 'package:flutter_html/flutter_html.dart';
 import 'package:flutter_html/html_parser.dart';
+import 'package:flutter_html/src/html_elements.dart';
 import 'package:flutter_html/style.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:flutter_html/flutter_html.dart';
 
 void main() {
   testWidgets("Check that default parser does not fail on empty data",
@@ -29,10 +29,12 @@ void testNewParser() {
 
   test("lexDomTree works correctly", () {
     StyledElement tree = HtmlParser.lexDomTree(
-        HtmlParser.parseHTML(
-            "Hello! <b>Hello, World!</b><i>Hello, New World!</i>"),
-        [],
-        []);
+      HtmlParser.parseHTML(
+          "Hello! <b>Hello, World!</b><i>Hello, New World!</i>"),
+      [],
+      [],
+      null,
+    );
     print(tree.toString());
   });
 
@@ -41,36 +43,43 @@ void testNewParser() {
         HtmlParser.parseHTML(
             "Hello, World! <a href='https://example.com'>This is a link</a>"),
         [],
-        []);
+        [],
+        null);
     print(tree.toString());
   });
 
   test("ContentElements work correctly", () {
     StyledElement tree = HtmlParser.lexDomTree(
-        HtmlParser.parseHTML("<img src='https://image.example.com' />"),
-        [],
-        []);
+      HtmlParser.parseHTML("<img src='https://image.example.com' />"),
+      [],
+      [],
+      null,
+    );
     print(tree.toString());
   });
 
   test("Nesting of elements works correctly", () {
     StyledElement tree = HtmlParser.lexDomTree(
-        HtmlParser.parseHTML(
-            "<div><div><div><div><a href='link'>Link</a><div>Hello, World! <b>Bold and <i>Italic</i></b></div></div></div></div></div>"),
-        [],
-        []);
+      HtmlParser.parseHTML(
+          "<div><div><div><div><a href='link'>Link</a><div>Hello, World! <b>Bold and <i>Italic</i></b></div></div></div></div></div>"),
+      [],
+      [],
+      null,
+    );
     print(tree.toString());
   });
 
   test("Video Content Source Parser works correctly", () {
-    ReplacedElement videoContentElement =
-        parseReplacedElement(HtmlParser.parseHTML("""
+    ReplacedElement videoContentElement = parseReplacedElement(
+      HtmlParser.parseHTML("""
       <video width="320" height="240" controls>
        <source src="movie.mp4" type="video/mp4">
        <source src="movie.ogg" type="video/ogg">
        Your browser does not support the video tag.
       </video>
-    """).getElementsByTagName("video")[0]);
+    """).getElementsByTagName("video")[0],
+      null,
+    );
 
     expect(videoContentElement, isA<VideoContentElement>());
     if (videoContentElement is VideoContentElement) {
@@ -82,14 +91,16 @@ void testNewParser() {
   });
 
   test("Audio Content Source Parser works correctly", () {
-    ReplacedElement audioContentElement =
-        parseReplacedElement(HtmlParser.parseHTML("""
+    ReplacedElement audioContentElement = parseReplacedElement(
+      HtmlParser.parseHTML("""
       <audio controls>
         <source src='audio.mp3' type='audio/mpeg'>
         <source src='audio.wav' type='audio/wav'>
         Your browser does not support the audio tag.
       </audio>
-    """).getElementsByTagName("audio")[0]);
+    """).getElementsByTagName("audio")[0],
+      null,
+    );
     expect(audioContentElement, isA<AudioContentElement>());
     if (audioContentElement is AudioContentElement) {
       expect(audioContentElement.showControls, equals(true),