support code folding

[maxheld83]

html_document() supports a code_folding argument, which, when echo = TRUE, allows the user to either collapse or show all code chunks (with a default).

I think letting the user decide whether she wants to see code chunks is a great idea, especially for longish vignettes.

[maxheld83]

there's a related issue for distill with more resources/ideas how to port over code folding,

[hadley]

Unfortunately we can't commit to supporting arbitrary html_document() features. If you want code folding, can't you already use <details>?

[fernandoroa]

I like this workaround https://stackoverflow.com/questions/37755037/how-to-add-code-folding-to-output-chunks-in-rmarkdown-html-documents#answer-37839683

[MLopez-Ibanez]

Unfortunately we can't commit to supporting arbitrary html_document() features. If you want code folding, can't you already use <details>?

The problem with <details> is that, if the code chunk generates a plot, the plots are also folded. While the code_folding argument only folds the code, not the plots.

[jayhesselberth]

Have you tried using code-fold: true in a quarto vignette in pkgdown?

[MLopez-Ibanez]

Reading vignettes/articles/benchmarks.qmd
Running `quarto render`
Error: 
! in callr subprocess.
Caused by error in `quarto::quarto_render(path, metadata_file = metadata_path, execute_dir = output_dir, …`:
! Error running quarto CLI from R.
Caused by error in `quarto::quarto_render()`:
✖ Error returned by quarto CLI.
ℹ Rerun with `quiet = FALSE` to see the full error message.
Caused by error:
! System command 'quarto' failed
ℹ See `$stderr` for standard error.
Type .Last.error to see the more details.
> .Last.error
<callr_error/rlib_error_3_0/rlib_error/error>
Error: 
! in callr subprocess.
Caused by error in `quarto::quarto_render(path, metadata_file = metadata_path, execute_dir = output_dir, …`:
! Error running quarto CLI from R.
Caused by error in `quarto::quarto_render()`:
✖ Error returned by quarto CLI.
ℹ Rerun with `quiet = FALSE` to see the full error message.
Caused by error:
! System command 'quarto' failed
ℹ See `$stderr` for standard error.
---
Backtrace:
1. pkgdown::build_site(run_dont_run = TRUE)
2. pkgdown:::build_site_external(pkg = pkg, examples = examples, run_dont_run = run_dont_run, …
3. callr::r(function(..., cli_colors, hyperlinks) { …
4. callr:::get_result(output = out, options)
5. callr:::throw(callr_remote_error(remerr, output), parent = fix_msg(remerr[[3]]))
---
Subprocess backtrace:
 1. pkgdown::build_site(...)
 2. pkgdown:::build_site_local(pkg = pkg, examples = examples, run_dont_run = run_dont_run, …
 3. pkgdown::build_articles(pkg, lazy = lazy, override = override, preview = FALSE)
 4. pkgdown:::build_quarto_articles(pkg, quiet = quiet)
 5. pkgdown:::quarto_render(pkg, src_path, quiet = quiet)
 6. quarto::quarto_render(path, metadata_file = metadata_path, execute_dir = output_dir, …
 7. quarto:::quarto_run(args, echo = TRUE, quarto_bin = quarto_bin)
 8. base::withCallingHandlers(processx::run(quarto_bin, args = args, echo = echo, …
 9. processx::run(quarto_bin, args = args, echo = echo, error_on_status = TRUE, …
10. base::throw(new_process_error(res, call = sys.call(), echo = echo, …
11. | base::signalCondition(cond)
12. (function (e) …
13. quarto:::wrap_quarto_error(e, args, .call = .call)
14. cli::cli_abort(msg, call = .call, parent = cnd, )
15. | rlang::abort(message, ..., call = call, use_cli_format = TRUE, …
16. | rlang:::signal_abort(cnd, .file)
17. | base::signalCondition(cnd)
18. (function (e) …
19. cli::cli_abort(c(`!` = "Error running quarto CLI from R."), call = .call, …
20. | rlang::abort(message, ..., call = call, use_cli_format = TRUE, …
21. | rlang:::signal_abort(cnd, .file)
22. | base::signalCondition(cnd)
23. global (function (e) …

[MLopez-Ibanez]

Surprisingly, it works when calling:

quarto::quarto_render("vignettes/articles/benchmarks.qmd")

so it seems a problem with pkgdown. On the bright side, code-fold: true works as expected.

I guess I'll wait until quarto+pkgdown becomes more stable...

[fabern]

For me pkgdown v2.2.0 has fixed this (in this PR here: #2948). It works now with code-fold: true.

In my case it was due to using external files and thus requiring correct handling of the path (Issue #2846 "Cannot use external files with Quarto vignettes/articles").