search

r-lib / downlit

Syntax Highlighting and Automatic Linking
https://downlit.r-lib.org
Other
90 stars 22 forks source link

downlit does not keep code source option set with knitr #149

Open cderv opened 2 years ago

cderv commented 2 years ago

knitr supports class.source and attr.source to add class and attributes on fenced code blocks

Take this example 

---
output: 
  rmarkdown::html_document:
    highlight: pygments
---

```{r select1, class.source = "my-class"}
print("Hello there")

This is the markdown produced by **knitr**

````markdown
```{.r .my-class}
print("Hello there")

and `my-class` will be added by Pandoc to `<pre>` in code block
````html
<div class="sourceCode" id="cb1">
<pre class="sourceCode r my-class"><code class="sourceCode r">
<span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="fu">print</span>(<span class="st">&quot;Hello there&quot;</span>)</span>
</code></pre></div>

downlit is not saving the addition classes to put them back in the new <pre> that it creates.

Related to https://github.com/r-lib/downlit/issues/133 which is slightly related as order of classes on pre messes up downlit_html_path().

A fix should take into account both issues probably

Initially reported in https://github.com/r-lib/pkgdown/issues/2147 by https://github.com/r-lib/pkgdown/issues/2147