Restore Quarto callout markup in a pkgdown-rendered HTML file

pkgdown renders .qmd articles with theme: "none" and minimal: TRUE (see pkgdown:::quarto_format()), which strips the CSS Quarto callouts rely on. Under those settings, Quarto's callout Lua filter falls back to a plain, class-less blockquote:

Usage

fix_quarto_callouts(html_path, qmd_path = NULL)

Arguments

html_path

Path to an HTML file to rewrite in place.

qmd_path

Optional path to the .qmd source that produced html_path, used to recover callout types lost to custom titles.

Value

The number of callouts rewritten, invisibly.

Details

<div>
<blockquote>
<p><strong>Note</strong></p>
<p>Hello note</p>
</blockquote>
</div>

This function finds that pattern - an attribute-less <div> whose only child is a <blockquote> whose first child is a <p> containing nothing but a <strong> - and rewrites it into Quarto's native callout markup (div.callout.callout-style-default.callout-<type>), so it can be styled by the CSS bundled with this package (see quartofix()).

A hand-written blockquote is never wrapped in a bare <div> by Pandoc, so this signature does not collide with genuine author content.

If a callout used a custom title (## My Title instead of the default), pkgdown's render loses the callout type along with the title text, so the type can't be read back from the HTML alone. Pass qmd_path (the original .qmd source, which pkgdown always ships alongside the built HTML) and this function recovers the type by reading the ::: {.callout-*} fences in document order and matching them positionally against the degraded callouts - this works regardless of custom titles. It's used only as a fallback when the count of callouts in the source doesn't match the count found in the HTML (which would mean a mismatch is possible), the title text is used to guess the type instead.