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showdownjs/showdown

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Original source (github.com)
Tags: tooling html markdown nodejs document-converter github.com
Clipped on: 2018-01-13
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  • Image (Asset 1/11) alt= like GitHub does, without needing 2 spaces at the end of the line (since v1.5.1)

    a line
wrapped in two

    turns into:

    <p>a line<br>
wrapped in two</p>

  • requireSpaceBeforeHeadingText: (boolean) [default false] Makes adding a space between # and the header text mandatory (since v1.5.3)

  • ghMentions: (boolean) [default false] Enables github @mentions, which link to the username mentioned (since v1.6.0)

  • ghMentionsLink: (string) [default https://github.com/{u}] Changes the link generated by @mentions. Showdown will replace {u} with the username. Only applies if ghMentions option is enabled. Example: @tivie with ghMentionsOption set to //mysite.com/{u}/profile will result in <a href="//mysite.com/tivie/profile">@tivie</a>

  • encodeEmails: (boolean) [default true] Enable e-mail addresses encoding through the use of Character Entities, transforming ASCII e-mail addresses into its equivalent decimal entities. (since v1.6.1)

    NOTE: Prior to version 1.6.1, emails would always be obfuscated through dec and hex encoding.

  • openLinksInNewWindow: (boolean) [default false] Open all links in new windows (by adding the attribute target="_blank" to <a> tags) (since v1.7.0)

  • backslashEscapesHTMLTags: (boolean) [default false] Support for HTML Tag escaping. ex: \<div>foo\</div> (since v1.7.2)

  • emoji: (boolean) [default false] Enable emoji support. Ex: this is a :smile: emoji For more info on available emojis, see https://github.com/showdownjs/showdown/wiki/Emojis (since v.1.8.0)

  • underline: (boolean) [default false] EXPERIMENTAL FEATURE Enable support for underline. Syntax is double or triple underscores ex: __underlined word__. With this option enabled, underscores are no longer parses into <em> and <strong>.

  • completeHTMLDocument: (boolean) [default false] Outputs a complete html document, including <html>, <head> and <body> tags' instead of an HTML fragment. (since v.1.8.5)

  • metadata: (boolean) [default false] Enable support for document metadata (defined at the top of the document between ««« and »»» or between --- and ---). (since v.1.8.5)

  • splitAdjacentBlockquotes: (boolean) [default false] Split adjacent blockquote blocks.(since v.1.8.6)

NOTE: Please note that until version 1.6.0, all of these options are DISABLED by default in the cli tool.

Flavors

You can also use flavors or presets to set the correct options automatically, so that showdown behaves like popular markdown flavors.

Currently, the following flavors are available:

  • original - original markdown flavor as in John Gruber's spec
  • vanilla - showdown base flavor (as from v1.3.1)
  • github - GFM (GitHub Flavored Markdown)

Global

showdown.setFlavor('github');

Instance

converter.setFlavor('github');

CLI Tool

Showdown also comes bundled with a Command Line Interface tool. You can check the CLI wiki page for more info

Integration with AngularJS

ShowdownJS project also provides seamlessly integration with AngularJS via a "plugin". Please visit https://github.com/showdownjs/ngShowdown for more information.

Integration with TypeScript

If you're using TypeScript you maybe want to use the types from DefinitelyTyped

Integration with SystemJS/JSPM

Integration with SystemJS can be obtained via the third party "system-md" plugin.

XSS vulnerability

Showdown doesn't sanitize the input. This is by design since markdown relies on it to allow certain features to be correctly parsed into HTML. This, however, means XSS injection is quite possible.

Please refer to the wiki article Markdown's XSS Vulnerability (and how to mitigate it) for more information.

Extensions

Showdown allows additional functionality to be loaded via extensions. (you can find a list of known showdown extensions here) You can also find a boilerplate, to create your own extensions in this repository

Client-side Extension Usage

<script src="showdown.js" />
<script src="twitter-extension.js" />

var converter = new showdown.Converter({ extensions: ['twitter'] });

Server-side Extension Usage

var showdown    = require('showdown'),
    myExtension = require('myExtension'),
    converter = new showdown.Converter({ extensions: ['myExtension'] });

Tests

A suite of tests is available which require node.js. Once node is installed, run the following command from the project root to install the dependencies:

npm install

Once installed the tests can be run from the project root using:

npm test

New test cases can easily be added. Create a markdown file (ending in .md) which contains the markdown to test. Create a .html file of the exact same name. It will automatically be tested when the tests are executed with mocha.

Contributing

If you wish to contribute please read the following quick guide.

Want a Feature?

You can request a new feature by submitting an issue. If you would like to implement a new feature feel free to issue a Pull Request.

Pull requests (PRs)

PRs are awesome. However, before you submit your pull request consider the following guidelines:

  • Search GitHub for an open or closed Pull Request that relates to your submission. You don't want to duplicate effort.

  • When issuing PRs that change code, make your changes in a new git branch based on master:

    git checkout -b my-fix-branch master

  • Documentation (i.e: README.md) changes can be made directly against master.

  • Run the full test suite before submitting and make sure all tests pass (obviously =P).

  • Try to follow our coding style rules. Breaking them prevents the PR to pass the tests.

  • Refrain from fixing multiple issues in the same pull request. It's preferable to open multiple small PRs instead of one hard to review big one.

  • If the PR introduces a new feature or fixes an issue, please add the appropriate test case.

  • We use commit notes to generate the changelog. It's extremely helpful if your commit messages adhere to the AngularJS Git Commit Guidelines.

  • If we suggest changes then:

    • Make the required updates.
    • Re-run the Angular test suite to ensure tests are still passing.
    • Rebase your branch and force push to your GitHub repository (this will update your Pull Request):
    git rebase master -i
git push origin my-fix-branch -f

  • After your pull request is merged, you can safely delete your branch.

If you have time to contribute to this project, we feel obliged that you get credit for it. These rules enable us to review your PR faster and will give you appropriate credit in your GitHub profile. We thank you in advance for your contribution!

Joining the team

We're looking for members to help maintaining Showdown. Please see this issue to express interest or comment on this note.

Credits

Full credit list at https://github.com/showdownjs/showdown/blob/master/CREDITS.md

Showdown is powered by:
webstorm