Within a package

pkgdown will automatically link to documentation and articles wherever it’s possible to do unambiguously. This includes:

Across packages

Linking to documentation in another package is straightforward. Just adapt the call in the usual way:

If pkgdown can find a pkgdown site for the remote package, it will link to it; otherwise it will link to https://rdrr.io/ for documentation, and CRAN for vignettes. In order for a pkgdown site to be findable, it needs to be listed in two places:

  • In the URL field in the DESCRIPTION, as in dplyr:

    URL: https://dplyr.tidyverse.org, https://github.com/tidyverse/dplyr
  • In the url field in _pkgdown.yml, as in dplyr

    url: https://dplyr.tidyverse.org

    When this field is defined, pkgdown generate a public facing pkgdown.yml file that provides metadata about the site:

    pandoc: '2.2'
    pkgdown: 1.3.0
    pkgdown_sha: ~
      compatibility: compatibility.html
      dplyr: dplyr.html
      dplyr_0.8.0: future/dplyr_0.8.0.html
      dplyr_0.8.0_new_hybrid: future/dplyr_0.8.0_new_hybrid.html
      programming: programming.html
      two-table: two-table.html
      window-functions: window-functions.html
      reference: https://dplyr.tidyverse.org/reference
      article: https://dplyr.tidyverse.org/articles

Now, when you build a pkgdown site for a package that links to the dplyr documentation (e.g., dplyr::mutate()), pkgdown looks first in dplyr’s DESCRIPTION to find its website, then it looks for pkgdown.yml, and uses the metadata to generate the correct links.