ExDoc

ExDoc is a tool to generate documentation for your Elixir projects. In case you are looking for documentation for Elixir itself, check out Elixir's website.

To learn about how to document your projects check out Elixir's writing documentation page.

Using ExDoc with Mix

To use ExDoc in your Mix projects, first add ExDoc as a dependency:

def deps do
  [{:ex_doc, "~> 0.14", only: :dev, runtime: false}]
end

After adding ExDoc as a dependency, run mix deps.get to install it.

ExDoc will automatically pull in information from your projects, like the application and version. However, you may want to set :name, :source_url and :homepage_url to have a nicer output from ExDoc, such as:

def project do
  [app: :my_app,
   version: "0.1.0-dev",
   deps: deps(),

   # Docs
   name: "MyApp",
   source_url: "https://github.com/USER/PROJECT",
   homepage_url: "http://YOUR_PROJECT_HOMEPAGE",
   docs: [main: "MyApp", # The main page in the docs
          logo: "path/to/logo.png",
          extras: ["README.md"]]]
end

Now you are ready to generate your project documentation with mix docs.

To see all options available when generating docs, run mix help docs. You may have to run mix docs or mix compile first.

Using ExDoc via command line

You can ExDoc via the command line as follows:

1. First clone and compile it:

   $ git clone https://github.com/elixir-lang/ex_doc.git
   $ cd ex_doc
   $ mix do deps.get, compile

2. Then you are ready to use it in your projects. First, move into your project directory and make sure it is already compiled:

   $ cd PATH_TO_YOUR_PROJECT
   $ mix compile

3. Next invoke the ex_doc executable from your project:

   $ PATH_TO_YOUR_EXDOC/bin/ex_doc "PROJECT_NAME" "PROJECT_VERSION" path/to/project/ebin -m "PROJECT_MODULE" -u "https://github.com/GITHUB_USER/GITHUB_REPO" -l path/to/logo.png

4. By default, ex_doc produces HTML files, but, you can also create a EPUB document passing the option --formatter epub:

   $ PATH_TO_YOUR_EXDOC/bin/ex_doc "PROJECT_NAME" "PROJECT_VERSION" path/to/project/ebin -m "PROJECT_MODULE" -u "https://github.com/GITHUB_USER/GITHUB_REPO" -l path/to/logo.png -f epub

For example, here are some acceptable values:

PROJECT_NAME    => Ecto
PROJECT_VERSION => 0.1.0
PROJECT_MODULE  => Ecto (the main module provided by the library)
GITHUB_USER     => elixir-lang
GITHUB_REPO     => ecto

Auto-linking

ExDoc will automatically generate links across modules and functions if you enclose them in backticks:

• By referring to a module, function, type or callback from your project, such as `MyModule`, ExDoc will automatically link to those
• By referring to a module, function, type or callback from Elixir, such as `String`, ExDoc will automatically link to Elixir's stable documentation
• By referring to a module or function from erlang, such as (`:erlang`), ExDoc will automatically link to the Erlang documentation
• By referring to a module, function, type or callback from any of your dependencies, such as `MyDep`, ExDoc will automatically link to that dependency documentation on hexdocs.pm (the link can be configured by setting docs: [deps: [my_dep: "https://path/to/docs/"]] in your mix.exs)

ExDoc supports linking to modules (`MyModule`), functions (`MyModule.function/1`), types (`t:MyModule.type/2`) and callbacks (`c:MyModule.callback/3`). If you want to link a function, type or callback in the current module, you may skip the module name, such as `function/1`.

Changing the Markdown tool

In the examples above, we have used Earmark to convert Markdown to HTML. If you prefer, you can also use hoedown (in C) or cmark (in C).

Hoedown

Hoedown is a standard compliant Markdown parser written in C. To use hoedown, add the elixir NIF wrapper markdown as a dependency to your project:

{:markdown, github: "devinus/markdown"}

Update your project configuration to use hoedown:

config :ex_doc, :markdown_processor, ExDoc.Markdown.Hoedown

Cmark

Cmark is a CommonMark parser written in C. To use cmark add the elixir NIF wrapper cmark.ex as a dependency to your project:

{:cmark, "~> 0.6", only: :dev}

Update your project configuration to use Cmark:

config :ex_doc, :markdown_processor, ExDoc.Markdown.Cmark

License

ExDoc source code is released under Apache 2 License. The generated contents, however, are under different licenses based on projects used to help render HTML, including CSS, JS, and other assets.

Check the LICENSE file for more information.