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| 1 | +import 'package:flutter/material.dart'; |
| 2 | +import 'package:flutter_widget_from_html_core/flutter_widget_from_html_core.dart'; |
| 3 | +import 'package:html/dom.dart' as h; |
| 4 | +import 'package:html/dom_parsing.dart'; |
| 5 | +import 'package:html/parser.dart'; |
| 6 | +import 'package:markdown/markdown.dart' as m; |
| 7 | +import 'package:markdown_widget/markdown_widget.dart'; |
| 8 | + |
| 9 | +void htmlToMarkdown(h.Node? node, int deep, List<m.Node> mNodes) { |
| 10 | + if (node == null) return; |
| 11 | + if (node is h.Text) { |
| 12 | + mNodes.add(m.Text(node.text)); |
| 13 | + } else if (node is h.Element) { |
| 14 | + final tag = node.localName; |
| 15 | + final List<m.Node> children = []; |
| 16 | + for (final e in node.children) { |
| 17 | + htmlToMarkdown(e, deep + 1, children); |
| 18 | + } |
| 19 | + m.Element element; |
| 20 | + if (tag == MarkdownTag.img.name || tag == 'video') { |
| 21 | + element = HtmlElement(tag!, children, node.text); |
| 22 | + element.attributes.addAll(node.attributes.cast()); |
| 23 | + } else { |
| 24 | + element = HtmlElement(tag!, children, node.text); |
| 25 | + element.attributes.addAll(node.attributes.cast()); |
| 26 | + } |
| 27 | + mNodes.add(element); |
| 28 | + } |
| 29 | +} |
| 30 | + |
| 31 | +final RegExp tableRep = RegExp(r'<table[^>]*>', multiLine: true); |
| 32 | + |
| 33 | +final RegExp htmlRep = RegExp(r'<[^>]*>', multiLine: true); |
| 34 | + |
| 35 | +///parse [m.Node] to [h.Node] |
| 36 | +List<SpanNode> parseHtml( |
| 37 | + m.Text node, { |
| 38 | + ValueCallback<dynamic>? onError, |
| 39 | + WidgetVisitor? visitor, |
| 40 | + TextStyle? parentStyle, |
| 41 | +}) { |
| 42 | + try { |
| 43 | + final text = node.textContent.replaceAll( |
| 44 | + visitor?.splitRegExp ?? WidgetVisitor.defaultSplitRegExp, |
| 45 | + '', |
| 46 | + ); |
| 47 | + if (!text.contains(htmlRep)) return [TextNode(text: node.text)]; |
| 48 | + final h.DocumentFragment document = parseFragment(text); |
| 49 | + return HtmlToSpanVisitor( |
| 50 | + visitor: visitor, |
| 51 | + parentStyle: parentStyle, |
| 52 | + ).toVisit(document.nodes.toList()); |
| 53 | + } catch (e) { |
| 54 | + onError?.call(e); |
| 55 | + return [TextNode(text: node.text)]; |
| 56 | + } |
| 57 | +} |
| 58 | + |
| 59 | +class HtmlElement extends m.Element { |
| 60 | + @override |
| 61 | + final String textContent; |
| 62 | + |
| 63 | + HtmlElement(super.tag, super.children, this.textContent); |
| 64 | +} |
| 65 | + |
| 66 | +class HtmlToSpanVisitor extends TreeVisitor { |
| 67 | + final List<SpanNode> _spans = []; |
| 68 | + final List<SpanNode> _spansStack = []; |
| 69 | + final WidgetVisitor visitor; |
| 70 | + final TextStyle parentStyle; |
| 71 | + |
| 72 | + HtmlToSpanVisitor({WidgetVisitor? visitor, TextStyle? parentStyle}) |
| 73 | + : visitor = visitor ?? WidgetVisitor(), |
| 74 | + parentStyle = parentStyle ?? const TextStyle(); |
| 75 | + |
| 76 | + List<SpanNode> toVisit(List<h.Node> nodes) { |
| 77 | + _spans.clear(); |
| 78 | + for (final node in nodes) { |
| 79 | + final emptyNode = ConcreteElementNode(style: parentStyle); |
| 80 | + _spans.add(emptyNode); |
| 81 | + _spansStack.add(emptyNode); |
| 82 | + visit(node); |
| 83 | + _spansStack.removeLast(); |
| 84 | + } |
| 85 | + final result = List.of(_spans); |
| 86 | + _spans.clear(); |
| 87 | + _spansStack.clear(); |
| 88 | + return result; |
| 89 | + } |
| 90 | + |
| 91 | + @override |
| 92 | + void visitText(h.Text node) { |
| 93 | + final last = _spansStack.last; |
| 94 | + if (last is ElementNode) { |
| 95 | + final textNode = TextNode(text: node.text); |
| 96 | + last.accept(textNode); |
| 97 | + } |
| 98 | + } |
| 99 | + |
| 100 | + @override |
| 101 | + void visitElement(h.Element node) { |
| 102 | + final localName = node.localName ?? ''; |
| 103 | + final mdElement = m.Element(localName, []); |
| 104 | + mdElement.attributes.addAll(node.attributes.cast()); |
| 105 | + SpanNode spanNode = visitor.getNodeByElement(mdElement, visitor.config); |
| 106 | + if (spanNode is! ElementNode) { |
| 107 | + final n = ConcreteElementNode(tag: localName, style: parentStyle); |
| 108 | + n.accept(spanNode); |
| 109 | + spanNode = n; |
| 110 | + } |
| 111 | + final last = _spansStack.last; |
| 112 | + if (last is ElementNode) { |
| 113 | + last.accept(spanNode); |
| 114 | + } |
| 115 | + _spansStack.add(spanNode); |
| 116 | + for (final child in node.nodes.toList(growable: false)) { |
| 117 | + visit(child); |
| 118 | + } |
| 119 | + _spansStack.removeLast(); |
| 120 | + } |
| 121 | +} |
| 122 | + |
| 123 | +class CustomTextNode extends ElementNode { |
| 124 | + final String text; |
| 125 | + final MarkdownConfig config; |
| 126 | + final WidgetVisitor visitor; |
| 127 | + bool isTable = false; |
| 128 | + |
| 129 | + CustomTextNode(this.text, this.config, this.visitor); |
| 130 | + |
| 131 | + @override |
| 132 | + InlineSpan build() { |
| 133 | + if (isTable) { |
| 134 | + //deal complex table tag with html core widget |
| 135 | + return WidgetSpan(child: HtmlWidget(text)); |
| 136 | + } else { |
| 137 | + return super.build(); |
| 138 | + } |
| 139 | + } |
| 140 | + |
| 141 | + @override |
| 142 | + void onAccepted(SpanNode parent) { |
| 143 | + final textStyle = config.p.textStyle.merge(parentStyle); |
| 144 | + children.clear(); |
| 145 | + if (!text.contains(htmlRep)) { |
| 146 | + accept(TextNode(text: text, style: textStyle)); |
| 147 | + return; |
| 148 | + } |
| 149 | + //Intercept as table tag |
| 150 | + if (text.contains(tableRep)) { |
| 151 | + isTable = true; |
| 152 | + accept(parent); |
| 153 | + return; |
| 154 | + } |
| 155 | + |
| 156 | + //The remaining ones are processed by the regular HTML processing. |
| 157 | + final spans = parseHtml( |
| 158 | + m.Text(text), |
| 159 | + visitor: WidgetVisitor( |
| 160 | + config: visitor.config, |
| 161 | + generators: visitor.generators, |
| 162 | + richTextBuilder: visitor.richTextBuilder, |
| 163 | + ), |
| 164 | + parentStyle: parentStyle, |
| 165 | + ); |
| 166 | + for (final element in spans) { |
| 167 | + isTable = false; |
| 168 | + accept(element); |
| 169 | + } |
| 170 | + } |
| 171 | +} |
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