# Introduction to pkgdown

The goal of pkgdown is to make it easy to make an elegant and useful package website with a minimum of work. You can get a basic website up and running in just a couple of minutes:

    # Run once to configure package to use pkgdown
    usethis::use_pkgdown()
    # Run to build the website
    pkgdown::build_site()

If you’re using GitHub, we also recommend setting up GitHub actions to automatically build and publish your site:

    usethis::use_pkgdown_github_pages()

While you’ll get a decent website without any additional work, if you want a website that really pops, you’ll need to read the rest of this vignette. It starts by showing you how to configure pkgdown with a `_pkgdown.yml`. You’ll learn about the main components of the site (the home page, reference, articles, and news), and then how to publish and promote your site.

## Metadata

You can override pkgdown’s defaults with a YAML file called `_pkgdown.yml`1. The most important field is `url`, which gives the final location of the site:

    url: https://pkgdown.r-lib.org

`url` is used throughout the site to generate absolute urls where they are needed.

Another important option is `template`, which allows you to control the overall appearance of your site:

    template:
      bootstrap: 5
      bootswatch: cerulean

You can learn more about controlling the appearance of your site in `vignette("customise")`.

### Language

If your documentation (`.Rd` and `.Rmd`) is written in a language other than English, declare it by setting setting `lang` to the two letter language code for your language:

    lang: fr

This will be used to set the language of the web page and to translate the English words that pkgdown generates on your site. Current available translations are:

- `de`: German
- `dk`: Danish
- `es`: Spanish
- `fr`: French
- `ko`: Korean
- `pt`: Portuguese
- `tr`: Turkish
- `zh_CN`: Chinese (simplified)

## Home page

The contents of home page are automatically generated from `index.md` or `README.md`. pkgdown tries them in order, so it’s possible to have a different display on GitHub and pkgdown by providing both files. The homepage also includes a sidebar full of useful links; see `?build_home` for how these are generated and how you can customise them.

## Reference

pkgdown creates a function reference in `reference/` that includes one page for each `.Rd` help topic in `man/`. The translation of individual help topics from Rd to HTML is generally straightforward, but there are a couple of things you should bear in mind:

- pkgdown does its best to autolink all references to help topics and articles described in `vignette("linking")`.

- pkgdown executes all examples, inserting the rendered results in the generated HTML files.

By default, pkgdown generates a reference index that is just an alphabetically-ordered list of functions. The index is much more useful with human curation because functions can be grouped and described in categories. To override the default, provide a `reference` field in `_pkgdown.yml`.

Each entry in `reference` can take one of three forms:

- A title, defined by `title` and optional `desc` (description) fields.
- A subtitle, defined by `subtitle` and optional `desc` (description) fields.
- A list of topics defined by a `contents` field.

    reference:
    - title: "Connecting to Spark"
      desc: >
        Functions for installing Spark components and managing
        connections to Spark
      contents:
      - spark_config
      - spark_connect
      - spark_disconnect
      - spark_install
      - spark_log
    - title: "Reading and Writing Data"
      desc: "Functions for reading and writing Spark DataFrames."
      contents:
      - starts_with("spark_read")
      - starts_with("spark_write")
      - matches("saveload")

Note the use of `starts_with()` to select all functions with a common prefix. You can also use `ends_with()` and `matches()`. See complete details in `?build_reference`.

While iterating on the reference index you might want to run `pkgdown::build_reference_index()`. It just re-builds the index page, making it faster to quickly change `_pkgdown.yml` and see how it affects your site.

## Articles

pkgdown will automatically build all vignettes found in `vignettes/`, translating them to HTML files in `articles/`. Due to the way that pkgdown has to integrate RMarkdown generated HTML with its own HTML, relatively little control is available over the output format. You can see the details in `?build_articles`.

If you want to include an article on the website but not in the package (e.g., because it’s large), you can either place it in a subdirectory of `vignettes/` (e.g. `vignettes/web_only`) or add it to `.Rbuildignore` (and make sure that there’s no `vignettes:` section in the yaml header). In the extreme case where you want to produce only articles but not vignettes, you should add the complete `vignettes/` directory to `.Rbuildignore` and ensure that DESCRIPTION does not have a `VignetteBuilder` field.

## News

If `NEWS.md` is present, it will be rendered into a single-page changelog based on markdown level headings. pkgdown assumes your `NEWS.md` is formatted using level one headings (`#`) to specify package name and version number, and level two headings (`##`) to provide topical organization for each release.

    # pkgdown 1.1.0

    ## Bug Fixes

    * Lots of them

    # pkgdown 1.0.0

    * This is the first release of pkgdown.

See more suggestions for writing news bullets in the tidyverse style guide.

See `?build_news` for more customisation options including how to:

- Create one page for each major version and related minor versions.
- Add release announcements to the news navbar drop-down.

## Publishing

If you use GitHub, there are two ways to publish your site on GitHub Pages:

- Build the site locally, check in the docs directory, then configure GitHub Pages to use that directory.

- Use GitHub actions to automatically build and publish the site every time you make a change. The easiest way to set this up is to run `usethis::use_pkgdown_github_pages()`.

## Promoting

Once your finalized site is built and published on the web, you should publicize its URL in a few places:

1. The `URL` field of your package `DESCRIPTION`, alongside a link to its source:

       URL: https://pkgdown.r-lib.org, https://github.com/r-lib/pkgdown

   (`usethis::use_pkgdown_github_pages()` does this for you.)

2. Your repository description on GitHub.

3. On Twitter (make sure to include `#rstats`).

1. You can also put it in `pkgdown/_pkgdown.yml` if you want to keep the package root clutter-free, or in `inst/_pkgdown.yml` if you want to make it available when your package is installed.↩︎