markdown 1.0.0

Build Status

A portable Markdown library written in Dart. It can parse Markdown into HTML on both the client and server.

Play with it at dart-lang.github.io/markdown.

Usage

import 'package:markdown/markdown.dart';

void main() {
  print(markdownToHtml('Hello *Markdown*'));
  //=> <p>Hello <em>Markdown</em></p>
}

Syntax extensions

A few Markdown extensions, beyond what was specified in the original Perl Markdown implementation, are supported. By default, the ones supported in CommonMark are enabled. Any individual extension can be enabled by specifying an Array of extension syntaxes in the blockSyntaxes or inlineSyntaxes argument of markdownToHtml.

The currently supported inline extension syntaxes are:

  • new InlineHtmlSyntax() - approximately CommonMark's definition of "Raw HTML".

The currently supported block extension syntaxes are:

  • const FencedCodeBlockSyntax() - Code blocks familiar to Pandoc and PHP Markdown Extra users.
  • const HeaderWithIdSyntax() - ATX-style headers have generated IDs, for link anchors (akin to Pandoc's auto_identifiers).
  • const SetextHeaderWithIdSyntax() - Setext-style headers have generated IDs for link anchors (akin to Pandoc's auto_identifiers).
  • const TableSyntax() - Table syntax familiar to GitHub, PHP Markdown Extra, and Pandoc users.

For example:

import 'package:markdown/markdown.dart';

void main() {
  print(markdownToHtml('Hello <span class="green">Markdown</span>',
      inlineSyntaxes: [new InlineHtmlSyntax()]));
  //=> <p>Hello <span class="green">Markdown</span></p>
}

Extension Sets

To make extension management easy, you can also just specify an extension set. Both markdownToHtml() and new Document() accept an extensionSet named parameter. Right now there are two extension sets:

  • ExtensionSet.none includes no extensions. With no extensions, Markdown documents will be parsed closely to how they might be parsed by the original Perl Markdown implementation.

  • ExtensionSet.commonMark includes two extensions so far, which bring this package's Markdown parsing closer to what is found in the CommonMark spec:

    • new InlineHtmlSyntax()
    • const FencedCodeBlockSyntax()
  • ExtensionSet.gitHub includes five extensions:

    • new InlineHtmlSyntax()
    • const FencedCodeBlockSyntax()
    • const HeaderWithIdSyntax(), which adds id attributes to ATX-style headers, for easy intra-document linking.
    • const SetextHeaderWithIdSyntax(), which adds id attributes to Setext-style headers, for easy intra-document linking.
    • const TableSyntax()

Custom syntax extensions

You can create and use your own syntaxes.

import 'package:markdown/markdown.dart';

void main() {
  var syntaxes = [new TextSyntax('nyan', sub: '~=[,,_,,]:3')];
  print(markdownToHtml('nyan', inlineSyntaxes: syntaxes));
  //=> <p>~=[,,_,,]:3</p>
}

### HTML Sanitization

This package offers no features in the way of HTML sanitization. Read Estevão
Soares dos Santos's great article, ["Markdown's XSS Vulnerability (and how to
mitigate it)"], to learn more.

The authors recommend that you perform any necessary sanitization on the
resulting HTML, for example via `dart:html`'s [NodeValidator].

CommonMark compliance

This package contains a number of files in the tool directory for tracking compliance with CommonMark.

Updating CommonMark stats when changing the implementation

  1. Update the library and test code, making sure that tests still pass.
  2. Run dart tool/stats.dart --update-files to update the per-test results tool/common_mark_stats.json and the test summary tool/common_mark_stats.txt.
  3. Verify that more tests now pass – or at least, no more tests fail.
  4. Make sure you include the updated stats files in your commit.

Updating the CommonMark test file for a spec update

  1. Check out the CommonMark source. Make sure you checkout a major release.

  2. Dump the test output overwriting the existing tests file.

    /path/to/common_mark_dir> python3 test/spec_tests.py --dump-tests \
      > /path/to/markdown.dart/tool/common_mark_tests.json
    
  3. Update the stats files as described above. Note any changes in the results.

  4. Update any references to the existing spec by search for http://spec.commonmark.org/0.28 in the repository. (Including this one.) Verify the updated links are still valid.

  5. Commit changes, including a corresponding note in CHANGELOG.md.

1.0.0

  • Fix issue where accept could cause an exception.
  • Remove deprecated escapeHtml function.
  • Fix compliance with auto-links, including support for email addresses.
  • Updated ExtensionSet.gitHub to more closely align with GitHub markdown.

0.11.4

  • Fix bug with lazy blockquote continuations (#162)
  • Fix bug with list item continuations (#156)

0.11.3

  • Deprecate escapeHtml. This code exists in dart:convert.

0.11.2

  • Fix reference code links inside blockquotes.
  • Add src/util.dart to exports.

0.11.1

  • Add version information:
    • dart bin/markdown.dart --version now shows the package version number.
    • The playground app now shows the version number.
  • Improve autolink parsing.
  • Add new table syntax: TableSyntax.
  • Add new ExtensionSet that includes the table syntax: ExtensionSet.gitHub.
  • For development: added tool/travis.sh.
  • Support multiline Setext headers.
  • Handle loose-vs-strict list items better.
  • Support ordered lists that start with a number other than 1.

0.11.0+1

  • Add playground app at https://dart-lang.github.io/markdown.

0.11.0

  • Parse HTML blocks more accurately, according to CommonMark.
  • Support shortcut reference links.
  • Don't allow an indented code block to interrupt a paragraph.
  • Change definition of "loose" and "strict" lists (items wrapped in paragraph tags vs not) to CommonMark's. The primary difference is that any single list item can trigger the entire list to be marked as "loose", rather than defining "looseness" on each specific item.
  • Fix paragraph continuations in blockquotes and list items.
  • Fix silly typing bug with tool/common_mark_stats.dart, which resulted in a dramatic overestimate of our CommonMark compliance.
  • There are now 427/613 (69%) passing CommonMark v0.25 specs.

0.10.1

  • Parse hard line breaks properly (#86). Thanks @mehaase!
  • Fix processing of [ ... ] syntax when no resolver is specified (#92).
  • There are now 401/613 (65%) passing CommonMark v0.24 specs. (Actually: after 0f64c8f the actual number of passing tests was 352/613 (57%).)

0.10.0

  • BREAKING: Now following the CommonMark spec for fenced code blocks. If a language (info string) is provided, it is added as a class to the code element with a language- prefix.
  • BREAKING: Now following the CommonMark spec for images. Previously, ![text](img.png) would compile too <a href="img.prg"><img src="img.prg" alt="text"></img></a>. That same code will now compile to <img src="img.png" alt="text" />.
  • Fix all strong mode errors.

0.9.0

  • BREAKING: The text [foo] (bar) no longer renders as an inline link (#53).
  • BREAKING: Change list parsing to allow lists to begin immediately after a preceding block element, without a blank line in between.
  • Formalize an API for Markdown extensions (#43).
  • Introduce ExtensionSets. FencedCodeBlock is considered an extension, but existing usage of markdownToHtml() and new Document() will use the default extension set, which is ExtensionSet.commonMark, which includes FencedCodeBlock.
  • Inline HTML syntax support; This is also considered an extension (#18).
  • The text [foo]() now renders as an inline link.
  • Whitespace now allowed between a link's destination and title (#65).
  • Header identifier support in the HeaderWithIdSyntax and SetextHeaderWithIdSyntax extensions.
  • Implement backslash-escaping so that Markdown syntax can be escaped, such as [foo]\(bar) ==> <p>[foo](bar)</p>.
  • Support for hard line breaks with either \\\n or <code> \n</code> (#30, #60).
  • New public method for BlockParser: peek(int linesAhead), meant for use in subclasses.
  • New public members for ListSyntax: blocksInList and determineBlockItems(), meant for use in subclasses.
  • Improve public docs (better, and more of them).

0.8.0

  • Breaking: Remove (probably unused) fields: LinkSyntax.resolved, InlineParser.currentSource.
  • Switch tests to use test instead of unittest.
  • Fix a few bugs in inline code syntax.
  • Ignore underscores inside words (#41).

0.7.2

  • Allow resolving links that contain inline syntax (#42).

0.7.1+3

  • Updated homepage.

0.7.1+2

  • Formatted code.

  • Updated readme.

1. Depend on it

Add this to your package's pubspec.yaml file:

dependencies:
  markdown: "^1.0.0"

2. Install it

You can install packages from the command line:

with pub:


$ pub get

with Flutter:


$ flutter packages get

Alternatively, your editor might support pub get or packages get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:

import 'package:markdown/markdown.dart';

Platforms

About

A library for converting markdown to HTML.

Author

Dart Team

Homepage

github.com/dart-lang/markdown

Documentation

www.dartdocs.org/documentation/markdown/1.0.0/

Uploader

kevmoo@google.com
sethladd@google.com
rnystrom@google.com
dgrove@google.com
srawlins@google.com

License

BSD (LICENSE)

Published

Nov 2, 2017