reftip

Hover tooltips for the function/reference links on an pkgdown or altdoc site. Inspired by DocumenterCodeBlocks.jl.

Build your docs like normal via pkgdown::build_site() or altdoc::render_docs() and then run:

reftip::add_tooltips()

It auto-detects which of the two built the site; pass site = "altdoc" or site = "pkgdown" explicitly if detection is ambiguous. Either way the tooltip, only touches references to the package’s own topics; anything else (base R, another package, code it can’t resolve) is left alone.

See it in action in live demo.

Installation

Install from GitHub:

pak:pak("https://github.com/BjarkeHautop/reftip")

Build locally

Both site types can be built from this repo using a couple of throwaway demo functions (see demo/demo.R) that exist only to show off the tooltips:

pkgload::load_all()

# altdoc
source("altdoc/build-site.R")
build_site()

# pkgdown
source("pkgdown/build-site.R")
build_site()

Open docs/index.html (altdoc) or docs-pkgdown/index.html (pkgdown) afterward and hover over functions to see it in action.

What’s in the tooltip

• The matched \usage{} line,
• The first sentence of \description{}.

If the description’s first sentence runs past 200 characters add_tooltips() warns, naming the Rd file, so you know to shorten it. Pass quiet = TRUE to suppress.

Known limitations

• A generic call like print(x) isn’t resolved, since that needs knowing x’s class at runtime, and reftip only reads man/*.Rd. It doesn’t evaluate any code.
• Same reason obj$method() (R6) isn’t resolved: nothing says which class’s methods to look up.
• An Rd page with several \alias{}es sharing one \usage{} block (an S3 generic plus its methods) shows that whole block in the tooltip, not just the one alias’s line.