| // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| import 'dart:collection'; |
| |
| import 'ast.dart'; |
| import 'block_parser.dart'; |
| import 'document.dart'; |
| import 'extension_set.dart'; |
| import 'inline_parser.dart'; |
| |
| /// Converts the given string of Markdown to HTML. |
| String markdownToHtml(String markdown, |
| {Iterable<BlockSyntax> blockSyntaxes, |
| Iterable<InlineSyntax> inlineSyntaxes, |
| ExtensionSet extensionSet, |
| Resolver linkResolver, |
| Resolver imageLinkResolver, |
| bool inlineOnly: false}) { |
| var document = new Document( |
| blockSyntaxes: blockSyntaxes, |
| inlineSyntaxes: inlineSyntaxes, |
| extensionSet: extensionSet, |
| linkResolver: linkResolver, |
| imageLinkResolver: imageLinkResolver); |
| |
| if (inlineOnly) return renderToHtml(document.parseInline(markdown)); |
| |
| // Replace windows line endings with unix line endings, and split. |
| var lines = markdown.replaceAll('\r\n', '\n').split('\n'); |
| |
| return renderToHtml(document.parseLines(lines)) + '\n'; |
| } |
| |
| /// Renders [nodes] to HTML. |
| String renderToHtml(List<Node> nodes) => new HtmlRenderer().render(nodes); |
| |
| /// Translates a parsed AST to HTML. |
| class HtmlRenderer implements NodeVisitor { |
| static final _blockTags = new RegExp('blockquote|h1|h2|h3|h4|h5|h6|hr|p|pre'); |
| |
| StringBuffer buffer; |
| Set<String> uniqueIds; |
| |
| HtmlRenderer(); |
| |
| String render(List<Node> nodes) { |
| buffer = new StringBuffer(); |
| uniqueIds = new LinkedHashSet<String>(); |
| |
| for (final node in nodes) node.accept(this); |
| |
| return buffer.toString(); |
| } |
| |
| void visitText(Text text) { |
| buffer.write(text.text); |
| } |
| |
| bool visitElementBefore(Element element) { |
| // Hackish. Separate block-level elements with newlines. |
| if (buffer.isNotEmpty && _blockTags.firstMatch(element.tag) != null) { |
| buffer.write('\n'); |
| } |
| |
| buffer.write('<${element.tag}'); |
| |
| // Sort the keys so that we generate stable output. |
| var attributeNames = element.attributes.keys.toList(); |
| attributeNames.sort((a, b) => a.compareTo(b)); |
| |
| for (var name in attributeNames) { |
| buffer.write(' $name="${element.attributes[name]}"'); |
| } |
| |
| // attach header anchor ids generated from text |
| if (element.generatedId != null) { |
| buffer.write(' id="${uniquifyId(element.generatedId)}"'); |
| } |
| |
| if (element.isEmpty) { |
| // Empty element like <hr/>. |
| buffer.write(' />'); |
| |
| if (element.tag == 'br') { |
| buffer.write('\n'); |
| } |
| |
| return false; |
| } else { |
| buffer.write('>'); |
| return true; |
| } |
| } |
| |
| void visitElementAfter(Element element) { |
| buffer.write('</${element.tag}>'); |
| } |
| |
| /// Uniquifies an id generated from text. |
| String uniquifyId(String id) { |
| if (!uniqueIds.contains(id)) { |
| uniqueIds.add(id); |
| return id; |
| } |
| |
| var suffix = 2; |
| var suffixedId = '$id-$suffix'; |
| while (uniqueIds.contains(suffixedId)) { |
| suffixedId = '$id-${suffix++}'; |
| } |
| uniqueIds.add(suffixedId); |
| return suffixedId; |
| } |
| } |