feat: Add WrapperExtension helper (#1264)

Sub6Resources · May 15, 2023 · 2ffa1dd · 2ffa1dd
1 parent 8ac444b
commit 2ffa1dd
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Showing 22 changed files with 296 additions and 62 deletions.
diff --git a/example/lib/main.dart b/example/lib/main.dart
@@ -317,6 +317,14 @@ class MyHomePageState extends State<MyHomePage> {
             ),
           },
           extensions: [
+            TagWrapExtension(
+                tagsToWrap: {"table"},
+                builder: (child) {
+                  return SingleChildScrollView(
+                    scrollDirection: Axis.horizontal,
+                    child: child,
+                  );
+                }),
             TagExtension(
               tagsToExtend: {"tex"},
               builder: (context) => Math.tex(

diff --git a/lib/src/builtins/details_element_builtin.dart b/lib/src/builtins/details_element_builtin.dart
@@ -24,8 +24,8 @@ class DetailsElementBuiltIn extends HtmlExtension {
 
   @override
   InlineSpan build(ExtensionContext context,
-      Map<StyledElement, InlineSpan> Function() parseChildren) {
-    final childList = parseChildren();
+      Map<StyledElement, InlineSpan> Function() buildChildren) {
+    final childList = buildChildren();
     final children = childList.values;
 
     InlineSpan? firstChild = children.isNotEmpty ? children.first : null;

diff --git a/lib/src/builtins/image_builtin.dart b/lib/src/builtins/image_builtin.dart
@@ -72,7 +72,7 @@ class ImageBuiltIn extends HtmlExtension {
 
   @override
   InlineSpan build(ExtensionContext context,
-      Map<StyledElement, InlineSpan> Function() parseChildren) {
+      Map<StyledElement, InlineSpan> Function() buildChildren) {
     final element = context.styledElement as ImageElement;
 
     final imageStyle = Style(

diff --git a/lib/src/builtins/interactive_element_builtin.dart b/lib/src/builtins/interactive_element_builtin.dart
@@ -39,9 +39,9 @@ class InteractiveElementBuiltIn extends HtmlExtension {
 
   @override
   InlineSpan build(ExtensionContext context,
-      Map<StyledElement, InlineSpan> Function() parseChildren) {
+      Map<StyledElement, InlineSpan> Function() buildChildren) {
     return TextSpan(
-      children: parseChildren().values.map((childSpan) {
+      children: buildChildren().values.map((childSpan) {
         return _processInteractableChild(context, childSpan);
       }).toList(),
     );

diff --git a/lib/src/builtins/ruby_builtin.dart b/lib/src/builtins/ruby_builtin.dart
@@ -40,7 +40,7 @@ class RubyBuiltIn extends HtmlExtension {
 
   @override
   InlineSpan build(ExtensionContext context,
-      Map<StyledElement, InlineSpan> Function() parseChildren) {
+      Map<StyledElement, InlineSpan> Function() buildChildren) {
     StyledElement? node;
     List<Widget> widgets = <Widget>[];
     final rubySize = context.parser.style['rt']?.fontSize?.value ??

diff --git a/lib/src/builtins/styled_element_builtin.dart b/lib/src/builtins/styled_element_builtin.dart
@@ -409,7 +409,7 @@ class StyledElementBuiltIn extends HtmlExtension {
 
   @override
   InlineSpan build(ExtensionContext context,
-      Map<StyledElement, InlineSpan> Function() parseChildren) {
+      Map<StyledElement, InlineSpan> Function() buildChildren) {
     if (context.styledElement!.style.display == Display.listItem ||
         ((context.styledElement!.style.display == Display.block ||
                 context.styledElement!.style.display == Display.inlineBlock) &&
@@ -424,7 +424,7 @@ class StyledElementBuiltIn extends HtmlExtension {
           shrinkWrap: context.parser.shrinkWrap,
           childIsReplaced: ["iframe", "img", "video", "audio"]
               .contains(context.styledElement!.name),
-          children: parseChildren()
+          children: buildChildren()
               .entries
               .expandIndexed((i, child) => [
                     child.value,
@@ -441,7 +441,7 @@ class StyledElementBuiltIn extends HtmlExtension {
 
     return TextSpan(
       style: context.styledElement!.style.generateTextStyle(),
-      children: parseChildren()
+      children: buildChildren()
           .entries
           .expand((child) => [
                 child.value,

diff --git a/lib/src/builtins/text_builtin.dart b/lib/src/builtins/text_builtin.dart
@@ -44,7 +44,7 @@ class TextBuiltIn extends HtmlExtension {
 
   @override
   InlineSpan build(ExtensionContext context,
-      Map<StyledElement, InlineSpan> Function() parseChildren) {
+      Map<StyledElement, InlineSpan> Function() buildChildren) {
     final element = context.styledElement! as TextContentElement;
     return TextSpan(
       style: element.style.generateTextStyle(),

diff --git a/lib/src/builtins/vertical_align_builtin.dart b/lib/src/builtins/vertical_align_builtin.dart
@@ -23,12 +23,12 @@ class VerticalAlignBuiltIn extends HtmlExtension {
   }
 
   @override
-  InlineSpan build(ExtensionContext context, parseChildren) {
+  InlineSpan build(ExtensionContext context, buildChildren) {
     return WidgetSpan(
       child: Transform.translate(
         offset: Offset(0, _getVerticalOffset(context.styledElement!)),
         child: CssBoxWidget.withInlineSpanChildren(
-          children: parseChildren().values.toList(),
+          children: buildChildren().values.toList(),
           style: context.styledElement!.style,
         ),
       ),

diff --git a/lib/src/extension/helpers/image_extension.dart b/lib/src/extension/helpers/image_extension.dart
@@ -59,11 +59,11 @@ class ImageExtension extends ImageBuiltIn {
   }
 
   @override
-  InlineSpan build(ExtensionContext context, parseChildren) {
+  InlineSpan build(ExtensionContext context, buildChildren) {
     if (builder != null) {
       return builder!.call(context);
     } else {
-      return super.build(context, parseChildren);
+      return super.build(context, buildChildren);
     }
   }
 }
diff --git a/lib/src/extension/helpers/image_tap_extension.dart b/lib/src/extension/helpers/image_tap_extension.dart
@@ -44,8 +44,8 @@ class OnImageTapExtension extends ImageBuiltIn {
   }
 
   @override
-  InlineSpan build(ExtensionContext context, parseChildren) {
-    final children = parseChildren();
+  InlineSpan build(ExtensionContext context, buildChildren) {
+    final children = buildChildren();
 
     assert(children.keys.isNotEmpty,
         "The OnImageTapExtension has been thwarted! It no longer has an `img` child");

diff --git a/lib/src/extension/helpers/matcher_extension.dart b/lib/src/extension/helpers/matcher_extension.dart
@@ -38,7 +38,7 @@ class MatcherExtension extends HtmlExtension {
   }
 
   @override
-  InlineSpan build(ExtensionContext context, parseChildren) {
+  InlineSpan build(ExtensionContext context, buildChildren) {
     return builder(context);
   }
 }
diff --git a/lib/src/extension/helpers/tag_extension.dart b/lib/src/extension/helpers/tag_extension.dart
@@ -8,7 +8,10 @@ class TagExtension extends HtmlExtension {
   late final InlineSpan Function(ExtensionContext) builder;
 
   /// [TagExtension] allows you to extend the functionality of flutter_html
-  /// by defining the behavior of custom tags to return a child widget.
+  /// by defining a mapping from a custom or existing tag to a widget.
+  ///
+  /// If instead you'd like to wrap a tag (or custom tag) in a widget,
+  /// see [TagWrapExtension].
   TagExtension({
     required this.tagsToExtend,
     Widget? child,
@@ -23,8 +26,8 @@ class TagExtension extends HtmlExtension {
   }
 
   /// [TagExtension.inline] allows you to extend the functionality of
-  /// flutter_html by defining the behavior of custom tags to return
-  /// a child InlineSpan.
+  /// flutter_html by defining a mapping from a custom or existing tag
+  /// to an InlineSpan.
   TagExtension.inline({
     required this.tagsToExtend,
     InlineSpan? child,
@@ -42,7 +45,7 @@ class TagExtension extends HtmlExtension {
   Set<String> get supportedTags => tagsToExtend;
 
   @override
-  InlineSpan build(ExtensionContext context, parseChildren) {
+  InlineSpan build(ExtensionContext context, buildChildren) {
     return builder(context);
   }
 }
diff --git a/lib/src/extension/helpers/tag_wrap_extension.dart b/lib/src/extension/helpers/tag_wrap_extension.dart
@@ -0,0 +1,85 @@
+import 'package:flutter/widgets.dart';
+import 'package:flutter_html/src/css_box_widget.dart';
+import 'package:flutter_html/src/extension/html_extension.dart';
+import 'package:flutter_html/src/style.dart';
+import 'package:flutter_html/src/tree/styled_element.dart';
+import 'package:html/dom.dart' as html;
+
+class TagWrapExtension extends HtmlExtension {
+  final Set<String> tagsToWrap;
+  final Widget Function(Widget child) builder;
+
+  /// [TagWrapExtension] allows you to easily wrap a specific tag (or tags)
+  /// in another element. For example, you could wrap `<table>` in a
+  /// `SingleChildScrollView`:
+  ///
+  /// ```dart
+  /// extensions: [
+  ///   WrapperExtension(
+  ///     tagsToWrap: {"table"},
+  ///     builder: (child) {
+  ///       return SingleChildScrollView(
+  ///         scrollDirection: Axis.horizontal,
+  ///         child: child,
+  ///       );
+  ///     },
+  ///   ),
+  /// ],
+  /// ```
+  TagWrapExtension({
+    required this.tagsToWrap,
+    required this.builder,
+  });
+
+  @override
+  Set<String> get supportedTags => tagsToWrap;
+
+  @override
+  bool matches(ExtensionContext context) {
+    switch (context.currentStep) {
+      case CurrentStep.preparing:
+        return super.matches(context);
+      case CurrentStep.preStyling:
+      case CurrentStep.preProcessing:
+        return false;
+      case CurrentStep.building:
+        return context.styledElement is WrapperElement;
+    }
+  }
+
+  @override
+  StyledElement prepare(
+      ExtensionContext context, List<StyledElement> children) {
+    return WrapperElement(
+      child: context.parser.prepareFromExtension(
+        context,
+        children,
+        extensionsToIgnore: {this},
+      ),
+    );
+  }
+
+  @override
+  InlineSpan build(ExtensionContext context, buildChildren) {
+    final children = buildChildren();
+    final child = CssBoxWidget.withInlineSpanChildren(
+      children: children.values.toList(),
+      style: context.styledElement!.style,
+    );
+
+    return WidgetSpan(
+      child: builder.call(child),
+    );
+  }
+}
+
+class WrapperElement extends StyledElement {
+  WrapperElement({
+    required StyledElement child,
+  }) : super(
+          node: html.Element.tag("wrapper-element"),
+          style: Style(),
+          children: [child],
+          name: "[wrapper-element]",
+        );
+}
diff --git a/lib/src/extension/html_extension.dart b/lib/src/extension/html_extension.dart
@@ -8,6 +8,7 @@ export 'package:flutter_html/src/extension/helpers/tag_extension.dart';
 export 'package:flutter_html/src/extension/helpers/matcher_extension.dart';
 export 'package:flutter_html/src/extension/helpers/image_extension.dart';
 export 'package:flutter_html/src/extension/helpers/image_tap_extension.dart';
+export 'package:flutter_html/src/extension/helpers/tag_wrap_extension.dart';
 
 /// The [HtmlExtension] class allows you to customize the behavior of flutter_html
 /// or add additional functionality.
@@ -58,7 +59,7 @@ abstract class HtmlExtension {
   /// attached `Style` elements, into an `InlineSpan` tree that includes
   /// Widget/TextSpans that can be rendered in a RichText widget.
   InlineSpan build(ExtensionContext context,
-      Map<StyledElement, InlineSpan> Function() parseChildren) {
+      Map<StyledElement, InlineSpan> Function() buildChildren) {
     throw UnimplementedError(
         "Extension `$runtimeType` matched `${context.styledElement!.name}` but didn't implement `parse`");
   }

diff --git a/lib/src/html_parser.dart b/lib/src/html_parser.dart
@@ -92,6 +92,61 @@ class HtmlParser extends StatefulWidget {
         }
         onLinkTap?.call(url, attributes, element);
       };
+
+  /// Prepares the html node using one of the built-ins or HtmlExtensions
+  /// available. If none of the extensions matches, returns an
+  /// EmptyContentElement
+  StyledElement prepareFromExtension(
+    ExtensionContext extensionContext,
+    List<StyledElement> children, {
+    Set<HtmlExtension> extensionsToIgnore = const {},
+  }) {
+    // Loop through every extension and see if it can handle this node
+    for (final extension in extensions) {
+      if (!extensionsToIgnore.contains(extension) &&
+          extension.matches(extensionContext)) {
+        return extension.prepare(extensionContext, children);
+      }
+    }
+
+    // Loop through built in elements and see if they can handle this node.
+    for (final builtIn in builtIns) {
+      if (!extensionsToIgnore.contains(builtIn) &&
+          builtIn.matches(extensionContext)) {
+        return builtIn.prepare(extensionContext, children);
+      }
+    }
+
+    // If no extension or built-in matches, then return an empty content element.
+    return EmptyContentElement(node: extensionContext.node);
+  }
+
+  /// Builds the StyledElement into an InlineSpan using one of the built-ins
+  /// or HtmlExtensions available. If none of the extensions matches, returns
+  /// an empty TextSpan.
+  InlineSpan buildFromExtension(
+    ExtensionContext extensionContext,
+    Map<StyledElement, InlineSpan> Function() buildChildren, {
+    Set<HtmlExtension> extensionsToIgnore = const {},
+  }) {
+    // Loop through every extension and see if it can handle this node
+    for (final extension in extensions) {
+      if (!extensionsToIgnore.contains(extension) &&
+          extension.matches(extensionContext)) {
+        return extension.build(extensionContext, buildChildren);
+      }
+    }
+
+    // Loop through built in elements and see if they can handle this node.
+    for (final builtIn in builtIns) {
+      if (!extensionsToIgnore.contains(builtIn) &&
+          builtIn.matches(extensionContext)) {
+        return builtIn.build(extensionContext, buildChildren);
+      }
+    }
+
+    return const TextSpan(text: "");
+  }
 }
 
 class _HtmlParserState extends State<HtmlParser> {
@@ -189,22 +244,8 @@ class _HtmlParserState extends State<HtmlParser> {
     // Lex this element's children
     final children = node.nodes.map(_prepareHtmlTreeRecursive).toList();
 
-    // Loop through every extension and see if it can handle this node
-    for (final extension in widget.extensions) {
-      if (extension.matches(extensionContext)) {
-        return extension.prepare(extensionContext, children);
-      }
-    }
-
-    // Loop through built in elements and see if they can handle this node.
-    for (final builtIn in HtmlParser.builtIns) {
-      if (builtIn.matches(extensionContext)) {
-        return builtIn.prepare(extensionContext, children);
-      }
-    }
-
-    // If no extension or built-in matches, then return an empty content element.
-    return EmptyContentElement(node: node);
+    // Prepare the element from one of the extensions
+    return widget.prepareFromExtension(extensionContext, children);
   }
 
   /// Called before any styling is cascaded on the tree
@@ -353,26 +394,12 @@ class _HtmlParserState extends State<HtmlParser> {
     }
 
     // Generate a function that allows children to be generated
-    Map<StyledElement, InlineSpan> parseChildren() {
+    Map<StyledElement, InlineSpan> buildChildren() {
       return Map.fromEntries(tree.children.map((child) {
         return MapEntry(child, _buildTreeRecursive(child));
       }));
     }
 
-    // Loop through every extension and see if it can handle this node
-    for (final extension in widget.extensions) {
-      if (extension.matches(extensionContext)) {
-        return extension.build(extensionContext, parseChildren);
-      }
-    }
-
-    // Loop through built in elements and see if they can handle this node.
-    for (final builtIn in HtmlParser.builtIns) {
-      if (builtIn.matches(extensionContext)) {
-        return builtIn.build(extensionContext, parseChildren);
-      }
-    }
-
-    return const TextSpan(text: "");
+    return widget.buildFromExtension(extensionContext, buildChildren);
   }
 }