# ExDoc
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ExDoc is a tool to generate documentation for your Elixir projects. To see an example, [you can access Elixir's official docs](https://hexdocs.pm/elixir/).
To learn about how to document your projects, see [Elixir's writing documentation page](https://hexdocs.pm/elixir/writing-documentation.html).
To see all supported options, see the documentation for [mix docs](https://hexdocs.pm/ex_doc/Mix.Tasks.Docs.html).
## Features
ExDoc ships with many features:
* Automatically generates HTML and EPUB documents from your API documentation
* Support for custom pages and guides (in addition to the API reference)
* Support for custom grouping of modules, functions, and pages in the sidebar
* Generates HTML documentation accessible online and offline
* Responsive design with built-in layout for phones and tablets
* Customizable logo on the generated documentation
* Each documented entry contains a direct link back to the source code
* Full-text search
* Keyboard shortcuts (press `?` inside an existing documentation to bring the help dialog)
* Quick search with autocompletion support (`s` keyboard shortcut)
* Go-to shortcut to take to any HexDocs package documentation with autocomplete support (`g` keyboard shortcut)
* Support for night-mode (automatically detected according to the browser preferences)
* Show tooltips when mousing over a link to a module/function (works for the current project and across projects)
* A version dropdown to quickly switch to other versions (automatically configured when hosted on HexDocs)
## Using ExDoc with Mix
To use ExDoc in your Mix projects, first add ExDoc as a dependency.
If you are using Elixir v1.10, or later:
```elixir
def deps do
[
{:ex_doc, "~> 0.24", only: :dev, runtime: false},
]
end
```
If you are using Elixir v1.7, v1.8, or v1.9:
```elixir
def deps do
[
{:ex_doc, "~> 0.22.0", only: :dev, runtime: false},
]
end
```
If you are using Elixir v1.6, or earlier:
```elixir
def deps do
[
{:ex_doc, "~> 0.18.0", 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:
```elixir
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`.
## Using ExDoc via command line
You can ExDoc via the command line as follows:
1. Install ExDoc as an escript:
```bash
$ mix escript.install hex ex_doc
```
2. Then you are ready to use it in your projects. First, move into your project directory and make sure it is already compiled:
```bash
$ cd PATH_TO_YOUR_PROJECT
$ mix compile
```
3. Next invoke the `ex_doc` executable from your project:
```bash
$ 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
```
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
## Using ExDoc with Erlang projects
ExDoc is capable of generating documentation from Erlang's `edoc` annotations through the following steps:
1. Use Erlang/OTP 24+
2. Add the following to your `rebar.config`. This instructs `edoc` to generate doc chunks
instead of HTML docs:
```erlang
{edoc_opts, [
{doclet, edoc_doclet_chunks},
{layout, edoc_layout_chunks},
{dir, "_build/default/lib/<app>/doc"}]}.
```
Replace `<app>` with the name of your app.
3. Install ExDoc escript:
```bash
$ mix escript.install hex ex_doc
$ ex_doc --version
```
Make sure escript is in your system path, otherwise point to it directly.
4. Generate docs:
```bash
$ rebar3 edoc
$ ex_doc "PROJECT_NAME" "PROJECT_VERSION" _build/default/lib/<app>/ebin
```
5. If you're publishing docs to Hex.pm, first add the following to your `src/<app>.app.src`:
```erlang
{doc, "doc"}
```
This instructs rebar3 to get HTML docs from the directory "doc" and that's where ExDoc would generate the docs by default.
Now you can publish your docs:
```bash
$ rebar3 hex docs
```
6. If your project has dependencies and you want to generate links to them, you need to add the dependencies to the code path.
Suppose you're building `foo` that depends on `bar` and `baz`. Generate the docs with:
```bash
$ ex_doc "foo" "1.0.0" "_build/default/lib/foo/ebin" \
--paths "_build/default/lib/*/ebin"
```
## Auto-linking
ExDoc for Elixir 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 function, type, or callback from OTP, such as (`` `:queue.new/0` ``), ExDoc will automatically link to the OTP 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](https://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` ``.
You can also use a custom text, e.g.: `` [custom text](`MyModule.function/1`) ``. This also allows to refer to OTP modules, e.g.: `` [`:array`](`:array`) ``.
Link to extra pages like this: `` [Up and running](Up and running.md) `` (skipping the directory
the page is in), the final link will be automatically converted to `up-and-running.html`.
## Contributing
The easiest way to test changes to ExDoc is to locally rebuild the app and its own documentation:
1. Run `mix setup` to install all dependencies
2. Run `mix build` to generate docs. This is a custom alias that will build assets, recompile ExDoc, and output fresh docs into the `doc/` directory
3. If you want to contribute a pull request, please do not add to your commits the files generated in the `assets/` and `formatters/` folders
4. Run `mix lint` to check if the Elixir and JavaScript files are properly formatted.
You can run `mix fix` to let the JavaScript linter and Elixir formatter fix the code automatically before submitting your pull request
## License
ExDoc source code is released under [Apache 2 License](LICENSE). The generated contents, however, are under different licenses based on projects used to help render HTML, including CSS, JS, and other assets.
Any documentation generated by ExDoc, or any documentation generated by any "Derivative Works" (as specified in the Apache 2 License), must include a direct, readable, and visible link to the [ExDoc repository](https://github.com/elixir-lang/ex_doc) on each rendered material. For HTML pages, a rendered material represents every single page. For PDF, EPUB and other ebook formats, it means one entry for the whole material.
