Updated markdown library. This adds support for images in the doccumentation!

third_party/pkg/markdown/lib/src/inline_parser.dart

 // 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.
 
 library markdown.inline_parser;
 
 import 'ast.dart';
 import 'document.dart';
 import 'util.dart';
 
@@ skipping 11 matching lines @@
     // Since it is purely for optimization, it can be removed for debugging.
 
     // TODO(amouravski): this regex will glom up any custom syntaxes unless
     // they're at the beginning.
     new TextSyntax(r'\s*[A-Za-z0-9]+'),
 
     // The real syntaxes.
 
     new AutolinkSyntax(),
     new LinkSyntax(),
+    new ImageLinkSyntax(),
     // "*" surrounded by spaces is left alone.
     new TextSyntax(r' \* '),
     // "_" surrounded by spaces is left alone.
     new TextSyntax(r' _ '),
     // Leave already-encoded HTML entities alone. Ensures we don't turn
     // "&" into "&"
     new TextSyntax(r'&[#a-zA-Z0-9]*;'),
     // Encode "&".
     new TextSyntax(r'&', sub: '&'),
     // Encode "<". (Why not encode ">" too? Gruber is toying with us.)
@@ skipping 34 matching lines @@
   InlineParser(this.source, this.document)
     : _stack = <TagState>[] {
     /// User specified syntaxes will be the first syntaxes to be evaluated.
     if (document.inlineSyntaxes != null) {
       syntaxes = [];
       syntaxes.addAll(document.inlineSyntaxes);
       syntaxes.addAll(defaultSyntaxes);
     } else {
       syntaxes = defaultSyntaxes;
     }
-    // Custom link resolver goes after the generic text syntax.
-    syntaxes.insert(1, new LinkSyntax(linkResolver: document.linkResolver));
+    // Custom link resolvers goes after the generic text syntax.
+    syntaxes.insertAll(1, [
+      new LinkSyntax(linkResolver: document.linkResolver),
+      new ImageLinkSyntax(linkResolver: document.linkResolver)
+    ]);
   }
 
   List<Node> parse() {
     // Make a fake top tag to hold the results.
     _stack.add(new TagState(0, 0, null));
 
     while (!isDone) {
       bool matched = false;
 
       // See if any of the current tags on the stack match. We don't allow tags
@@ skipping 109 matching lines @@
 
 /// Matches autolinks like `<http://foo.com>`.
 class AutolinkSyntax extends InlineSyntax {
   AutolinkSyntax()
     : super(r'<((http|https|ftp)://[^>]*)>');
   // TODO(rnystrom): Make case insensitive.
 
   bool onMatch(InlineParser parser, Match match) {
     final url = match[1];
 
-    final anchor = new Element.text('a', escapeHtml(url));
-    anchor.attributes['href'] = url;
+    final anchor = new Element.text('a', escapeHtml(url))
+      ..attributes['href'] = url;
     parser.addNode(anchor);
 
     return true;
   }
 }
 
 /// Matches syntax that has a pair of tags and becomes an element, like `*` for
 /// `<em>`. Allows nested tags.
 class TagSyntax extends InlineSyntax {
   final RegExp endPattern;
@@ skipping 31 matching lines @@
     return '\](?:($refLink|$inlineLink)|)';
 
     // The groups matched by this are:
     // 1: Will be non-empty if it's either a ref or inline link. Will be empty
     //    if it's just a bare pair of square brackets with nothing after them.
     // 2: Contains the id inside [] for a reference-style link.
     // 3: Contains the URL for an inline link.
     // 4: Contains the title, if present, for an inline link.
   }
 
-  LinkSyntax({this.linkResolver})
-    : super(r'\[', end: linkPattern);
+  LinkSyntax({this.linkResolver, String pattern: r'\['})
+    : super(pattern, end: linkPattern);
 
-  bool onMatchEnd(InlineParser parser, Match match, TagState state) {
-    var url;
-    var title;
-
+  Node createNode(InlineParser parser, Match match, TagState state) {
     // If we didn't match refLink or inlineLink, then it means there was
     // nothing after the first square bracket, so it isn't a normal markdown
     // link at all. Instead, we allow users of the library to specify a special
     // resolver function ([linkResolver]) that may choose to handle
     // this. Otherwise, it's just treated as plain text.
-    if ((match[1] == null) || (match[1] == '')) {
-      if (linkResolver == null) return false;
+    if (isNullOrEmpty(match[1])) {
+      if (linkResolver == null) return null;
 
       // Only allow implicit links if the content is just text.
       // TODO(rnystrom): Do we want to relax this?
-      if (state.children.any((child) => child is! Text)) return false;
+      if (state.children.any((child) => child is! Text)) return null;
       // If there are multiple children, but they are all text, send the
       // combined text to linkResolver.
       var textToResolve = state.children.fold('',
           (oldVal, child) => oldVal + child.text);
+
       // See if we have a resolver that will generate a link for us.
-      final node = linkResolver(textToResolve);
-      if (node == null) return false;
+      return linkResolver(textToResolve);
+    } else {
+      Link link = getLink(parser, match, state);
+      if (link == null) return null;
 
-      parser.addNode(node);
-      return true;
+      final Element node = new Element('a', state.children)
+        ..attributes["href"] = escapeHtml(link.url)
+        ..attributes['title'] = escapeHtml(link.title);
+
+      cleanMap(node.attributes);
+      return node;
     }
+  }
 
+  Link getLink(InlineParser parser, Match match, TagState state) {
     if ((match[3] != null) && (match[3] != '')) {
       // Inline link like [foo](url).
-      url = match[3];
-      title = match[4];
+      var url = match[3];
+      var title = match[4];
 
       // For whatever reason, markdown allows angle-bracketed URLs here.
       if (url.startsWith('<') && url.endsWith('>')) {
         url = url.substring(1, url.length - 1);
       }
+
+      return new Link(null, url, title);
     } else {
+      var id;
       // Reference link like [foo] [bar].
-      var id = match[2];
-      if (id == '') {
+      if (match[2] == '')
         // The id is empty ("[]") so infer it from the contents.
         id = parser.source.substring(state.startPos + 1, parser.pos);
-      }
+      else
+        id = match[2];
 
       // References are case-insensitive.
       id = id.toLowerCase();
+      return parser.document.refLinks[id];
+    }
+  }
 
-      // Look up the link.
-      final link = parser.document.refLinks[id];
-      // If it's an unknown link just emit plaintext.
-      if (link == null) return false;
-
-      url = link.url;
-      title = link.title;
-    }
-
-    final anchor = new Element('a', state.children);
-    anchor.attributes['href'] = escapeHtml(url);
-    if ((title != null) && (title != '')) {
-      anchor.attributes['title'] = escapeHtml(title);
-    }
-
-    parser.addNode(anchor);
+  bool onMatchEnd(InlineParser parser, Match match, TagState state) {
+    Node node = createNode(parser, match, state);
+    if (node == null) return false;
+    parser.addNode(node);
     return true;
   }
 }
 
+/// Matches images like `![alternate text](url "optional title")` and
+/// `![alternate text][url reference]`.
+class ImageLinkSyntax extends LinkSyntax {
+  Resolver linkResolver;
+  ImageLinkSyntax({this.linkResolver})
+    : super(pattern: r'!\[');
+
+  Node createNode(InlineParser parser, Match match, TagState state) {
+    Node node = super.createNode(parser, match, state);
+    if (node == null) return null;
+
+    final Element imageElement = new Element.withTag("img")
+      ..attributes["src"] = node.attributes["href"]
+      ..attributes["title"] = node.attributes["title"]
+      ..attributes["alt"] = node.children
+        .map((e) => isNullOrEmpty(e) || e is! Text ? '' : e.text)
+        .join(' ');
+
+    cleanMap(imageElement.attributes);
+
+    node.children
+      ..clear()
+      ..add(imageElement);
+
+    return node;
+  }
+}
+
+
 /// Matches backtick-enclosed inline code blocks.
 class CodeSyntax extends InlineSyntax {
   CodeSyntax(String pattern)
     : super(pattern);
 
   bool onMatch(InlineParser parser, Match match) {
     parser.addNode(new Element.text('code', escapeHtml(match[1])));
     return true;
   }
 }
@@ skipping 64 matching lines @@
       parser.consume(endMatch[0].length);
     } else {
       // Didn't close correctly so revert to text.
       parser.start = startPos;
       parser.advanceBy(endMatch[0].length);
     }
 
     return null;
   }
 }