feat: break long words, remove large width settings

robert-virkus · robert-virkus · commit 6fc33b5333f5 · 2023-11-15T07:21:28.000+01:00
diff --git a/analysis_options.yaml b/analysis_options.yaml
@@ -92,7 +92,6 @@ linter:
     - prefer_const_literals_to_create_immutables
     - prefer_constructors_over_static_methods
     - prefer_contains
-    - prefer_equal_for_default_values
     - prefer_expression_function_bodies
     - prefer_final_fields
     - prefer_final_in_for_each
diff --git a/lib/src/dom/dark_mode_transformer.dart b/lib/src/dom/dark_mode_transformer.dart
@@ -14,8 +14,9 @@ class DarkModeTransformer extends DomTransformer {
     if (configuration.enableDarkMode) {
       ensureDocumentHeadIsAvailable(document);
       final style = Element.html(
-          '<style type="text/css">body {color: #FFFFFF; margin: 4px;}</style>');
-      document.head!.append(style);
+        '<style type="text/css">body {color: #FFFFFF; margin: 4px;}</style>',
+      );
+      document.head?.append(style);
     }
   }
 }
diff --git a/lib/src/dom/image_transformers.dart b/lib/src/dom/image_transformers.dart
@@ -12,8 +12,11 @@ class ImageTransformer extends DomTransformer {
   const ImageTransformer();
 
   @override
-  void process(Document document, MimeMessage message,
-      TransformConfiguration configuration) {
+  void process(
+    Document document,
+    MimeMessage message,
+    TransformConfiguration configuration,
+  ) {
     final imageElements = document.getElementsByTagName('img');
     final usedContentIds = <String>[];
     for (final imageElement in imageElements) {
diff --git a/lib/src/dom/link_transformers.dart b/lib/src/dom/link_transformers.dart
@@ -9,8 +9,11 @@ class EnsureRelationNoreferrerTransformer extends DomTransformer {
   const EnsureRelationNoreferrerTransformer();
 
   @override
-  void process(Document document, MimeMessage message,
-      TransformConfiguration configuration) {
+  void process(
+    Document document,
+    MimeMessage message,
+    TransformConfiguration configuration,
+  ) {
     final linkElements = document.getElementsByTagName('a');
     for (final linkElement in linkElements) {
       linkElement.attributes['rel'] = 'noopener noreferrer';
diff --git a/lib/src/dom/meta_transformers.dart b/lib/src/dom/meta_transformers.dart
@@ -15,12 +15,15 @@ class ViewPortTransformer extends DomTransformer {
       Element.html('<meta name="viewport" content="$_viewPortContent">');
   static final Element _contentTypeMetaElement = Element.html(
       '<meta http-equiv="Content-Type" content="text/html; charset=utf-8">');
-  static final Element _wordWrapStyleElement =
-      Element.html('<style type="text/css">* {word-wrap: break-word;}</style>');
+  static final Element _wordWrapStyleElement = Element.html(
+      '<style type="text/css">* {word-wrap: break-word; word-break: break-word;}</style>');
 
   @override
-  void process(Document document, MimeMessage message,
-      TransformConfiguration configuration) {
+  void process(
+    Document document,
+    MimeMessage message,
+    TransformConfiguration configuration,
+  ) {
     final metaElements = document.getElementsByTagName('meta');
     var viewportNeedsToBeAdded = true;
     var contentTypeNeedsToBeAdded = true;
diff --git a/lib/src/dom/script_transformers.dart b/lib/src/dom/script_transformers.dart
@@ -5,11 +5,14 @@ import '../enough_mail_html_base.dart';
 
 /// Removes script references from a DOM
 class RemoveScriptTransformer extends DomTransformer {
-  /// Craetes a new script removing transformer
+  /// Creates a new script removing transformer
   const RemoveScriptTransformer();
   @override
-  void process(Document document, MimeMessage message,
-      TransformConfiguration configuration) {
+  void process(
+    Document document,
+    MimeMessage message,
+    TransformConfiguration configuration,
+  ) {
     final scriptElements = document.getElementsByTagName('script');
     for (final scriptElement in scriptElements) {
       scriptElement.remove();
diff --git a/lib/src/dom/width_transformers.dart b/lib/src/dom/width_transformers.dart
@@ -0,0 +1,73 @@
+import 'package:enough_mail/mime.dart';
+import 'package:html/dom.dart';
+
+import '../enough_mail_html_base.dart';
+
+/// Removes any width attributes that are larger than the maxWidth
+class WidthTransformer extends DomTransformer {
+  /// Creates a [WidthTransformer]
+  const WidthTransformer();
+
+  @override
+  void process(
+    Document document,
+    MimeMessage message,
+    TransformConfiguration configuration,
+  ) {
+    final body = document.body;
+    if (body != null) {
+      _processElement(body, message, configuration);
+    }
+    final styleElements = document.getElementsByTagName('style');
+    for (final styleElement in styleElements) {
+      var text = styleElement.text;
+      int startIndex;
+      while ((startIndex = text.indexOf('-webkit-background-size:')) != -1) {
+        final endIndex =
+            text.indexOf(';', startIndex + '-webkit-background-size:'.length);
+        if (endIndex == -1) {
+          break;
+        }
+        text = startIndex == 0
+            ? text.substring(endIndex + 1)
+            : text.substring(0, startIndex) + text.substring(endIndex + 1);
+      }
+      styleElement.text = text;
+    }
+  }
+
+  void _processElement(
+    Element element,
+    MimeMessage message,
+    TransformConfiguration configuration,
+  ) {
+    final widthAttribute = element.attributes['width'];
+    if (widthAttribute != null) {
+      final width = int.tryParse(widthAttribute);
+      if (width != null) {
+        final maxWidth = configuration.attributeWidthMax;
+        if (width > maxWidth) {
+          element.attributes.remove('width');
+        }
+      }
+    }
+    final styleAttribute = element.attributes['style'];
+    if (styleAttribute != null) {
+      final widthIndex = styleAttribute.indexOf('width:');
+      if (widthIndex != -1) {
+        final semicolonIndex =
+            styleAttribute.indexOf(';', widthIndex + 'width:'.length);
+        if (semicolonIndex != -1) {
+          final newStyleAttribute = widthIndex == 0
+              ? styleAttribute.substring(semicolonIndex + 1)
+              : styleAttribute.substring(0, widthIndex) +
+                  styleAttribute.substring(semicolonIndex + 1);
+          element.attributes['style'] = newStyleAttribute;
+        }
+      }
+    }
+    for (final element in element.children) {
+      _processElement(element, message, configuration);
+    }
+  }
+}
diff --git a/lib/src/enough_mail_html_base.dart b/lib/src/enough_mail_html_base.dart
@@ -8,6 +8,7 @@ import 'dom/image_transformers.dart';
 import 'dom/link_transformers.dart';
 import 'dom/meta_transformers.dart';
 import 'dom/script_transformers.dart';
+import 'dom/width_transformers.dart';
 import 'text/convert_tags_text_transformer.dart';
 import 'text/linebreak_text_transformer.dart';
 import 'text/links_text_transformer.dart';
@@ -28,6 +29,7 @@ class TransformConfiguration {
     this.enableDarkMode = false,
     this.emptyMessageText = standardEmptyMessageText,
     this.plainTextHtmlTemplate = standardPlainTextHtmlTemplate,
+    this.attributeWidthMax = standardAttributeMaxWidth,
     this.customValues,
   });
 
@@ -44,6 +46,7 @@ class TransformConfiguration {
     String plainTextHtmlTemplate = standardPlainTextHtmlTemplate,
     List<DomTransformer>? customDomTransformers,
     List<TextTransformer>? customTextTransformers,
+    int attributeWidthMax = standardAttributeMaxWidth,
     Map<String, dynamic>? customValues,
   }) {
     final domTransformers = (customDomTransformers != null)
@@ -53,6 +56,7 @@ class TransformConfiguration {
         ? [...standardTextTransformers, ...customTextTransformers]
         : standardTextTransformers;
     maxImageWidth ??= standardMaxImageWidth;
+
     return TransformConfiguration(
       blockExternalImages: blockExternalImages,
       preferPlainText: preferPlainText,
@@ -62,6 +66,7 @@ class TransformConfiguration {
       domTransformers: domTransformers,
       textTransformers: textTransformers,
       plainTextHtmlTemplate: plainTextHtmlTemplate,
+      attributeWidthMax: attributeWidthMax,
       customValues: customValues,
     );
   }
@@ -96,6 +101,9 @@ class TransformConfiguration {
   /// before a plain text message without HTML part is converted into HTML
   final List<TextTransformer> textTransformers;
 
+  /// The maximum value for width attributes, defaults to 400.
+  final int attributeWidthMax;
+
   /// Optional custom values, `null` unless specified.
   final Map<String, dynamic>? customValues;
 
@@ -111,6 +119,7 @@ class TransformConfiguration {
     domTransformers: standardDomTransformers,
     textTransformers: standardTextTransformers,
     plainTextHtmlTemplate: standardPlainTextHtmlTemplate,
+    attributeWidthMax: standardAttributeMaxWidth,
   );
 
   /// The standard maximum image width is `null`, ie not restricted.
@@ -129,13 +138,17 @@ class TransformConfiguration {
   static const String standardEmptyMessageText =
       'This message has no contents.';
 
+  /// The standard maximum width for attributes is 400.
+  static const int standardAttributeMaxWidth = 400;
+
   /// The list of default DOM transformers
   static const List<DomTransformer> standardDomTransformers = [
     ViewPortTransformer(),
     RemoveScriptTransformer(),
     ImageTransformer(),
     EnsureRelationNoreferrerTransformer(),
     DarkModeTransformer(),
+    WidthTransformer(),
   ];
 
   /// The list of default text transformers
@@ -155,8 +168,11 @@ abstract class DomTransformer {
   /// Transforms the [document] of the [message] using [configuration].
   ///
   /// All changes will be visible to subsequent transformers.
-  void process(Document document, MimeMessage message,
-      TransformConfiguration configuration);
+  void process(
+    Document document,
+    MimeMessage message,
+    TransformConfiguration configuration,
+  );
 
   /// Adds a HEAD element if necessary
   void ensureDocumentHeadIsAvailable(Document document) {
diff --git a/pubspec.yaml b/pubspec.yaml
@@ -4,7 +4,7 @@ version: 2.0.1
 homepage: https://github.com/Enough-Software/enough_mail_html
 
 environment:
-  sdk: '>=2.18.0 <4.0.0'
+  sdk: '>=3.0.0 <4.0.0'
 
 dependencies:
   enough_mail: ^2.0.0
@@ -19,5 +19,5 @@ dependency_overrides:
   #   path: ../enough_mail/
 
 dev_dependencies:
-  lints: ^2.0.0
+  lints: ^3.0.0
   test: ^1.16.7

Original file line number	Diff line number	Diff line change
`@@ -14,8 +14,9 @@ class DarkModeTransformer extends DomTransformer {`
`14`	`14`	`if (configuration.enableDarkMode) {`
`15`	`15`	`ensureDocumentHeadIsAvailable(document);`
`16`	`16`	`final style = Element.html(`
`17`		`- '<style type="text/css">body {color: #FFFFFF; margin: 4px;}</style>');`
`18`		`- document.head!.append(style);`
	`17`	`+ '<style type="text/css">body {color: #FFFFFF; margin: 4px;}</style>',`
	`18`	`+ );`
	`19`	`+ document.head?.append(style);`
`19`	`20`	`}`
`20`	`21`	`}`
`21`	`22`	`}`