Feature request: custom syntax highlighting themes

[jefelino]

Since version 2.0, pandoc has supported custom syntax highlighting themes, provided in a .theme file which is passed as an argument to --highlight-style (see [https://pandoc.org/MANUAL.html#syntax-highlighting]()). But if I try to provide a custom theme file using the highlight field in my _output.yml file, bookdown halts with this error message:

Error in match.arg(highlight, highlighters()) : 
  'arg' should be one of “default”, “tango”, “pygments”, “kate”, “monochrome”, “espresso”, “zenburn”, “haddock”, “breezedark”
Calls: <Anonymous> ... get_base_format -> do.call -> <Anonymous> -> match.arg
Execution halted

Exited with status 1.

It would be better to allow parameters that include a .theme extension to go through to pandoc.

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[cderv]

Is this a question specific to bookdown or related to Rmarkdown ?

I believe you can do that in rmarkdown for html_document but only if you use a custom template too (by setting template argument). I think this is by design as the defaut rmarkdown template works well with provided theme.

Anyway, we need more information I think:

• Which format are you using ?
• Can you share what you set in _output.yml ?

Thank you !

[cderv]

This is a limitation of rmarkdown for now. It should be done there first https://github.com/rstudio/rmarkdown/issues/2035