# `mix docs`
[🔗](https://github.com/elixir-lang/ex_doc/blob/v0.40.1/lib/mix/tasks/docs.ex#L1)

Uses ExDoc to generate a static web page from the project documentation.

## Command line options

  * `--canonical`, `-n` - Indicate the preferred URL with
    `rel="canonical"` link element, defaults to no canonical path

  * `--formatter`, `-f` - Which formatters to use, `html`,
    `epub`, or `markdown`. This option can be given more than once. By default,
    `html`, `epub`, and `markdown` are generated.

  * `--language` - Specifies the language to annotate the
    EPUB output in valid [BCP 47](https://tools.ietf.org/html/bcp47)

  * `--open` - open browser window pointed to the documentation

  * `--output`, `-o` - Output directory for the generated
    docs, default: `"doc"`

  * `--proglang` - Chooses the main programming language: `elixir`
    or `erlang`

  * `--warnings-as-errors` - Exits with non-zero exit code if any warnings are found

The command line options have higher precedence than the options
specified in your `mix.exs` file below.

## Configuration

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

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

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

ExDoc also allows configuration specific to the documentation to
be set. The following options should be put under the `:docs` key
in your project's main configuration. The `:docs` options should
be a keyword list or a function returning a keyword list that will
be lazily executed. See all supported options in `ExDoc.generate/4`.

## Umbrella project

ExDoc can be used in an umbrella project and generates a single documentation
for all child apps. You can use the `:ignore_apps` configuration to exclude
certain projects in the umbrella from documentation.

Generating documentation per each child app can be achieved by running:

    mix cmd mix docs

See `mix help cmd` for more information.

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*Consult [api-reference.md](api-reference.md) for complete listing*