R: Avoid rioting in streets by supporting R Markdown in Positron

[jmcphers]

Goal

Support for R Markdown. We don't need to knock it out of the park, but we do need support for the basics:

• Run cells
• Preview documents
• Knit documents to format(s)
• Publish documents
• etc.

This should look a lot like what the Quarto extension does since the two have a lot of similarities.

Context

via @jjallaire:

Note that Positron currently does not support R Markdown and we don't have plans to add this unless there is rioting in the streets about it

Via @hadley:

I predict that you will need some basic Rmd support or there will be rioting

Via @DavisVaughan:

I think we have determined there would be rioting in the streets

Slack threads:

https://positpbc.slack.com/archives/C05M2EZCPGR/p1695387572152429
https://positpbc.slack.com/archives/C05M2EZCPGR/p1695737806600509

Support features in the existing VS Code R language support plugin:

https://github.com/REditorSupport/vscode-R/wiki/R-Markdown

[jmcphers]

See also discussion in #1043; the Quarto extension does provide some R Markdown functionality (but doesn't use R Markdown for rendering)

#1043 (comment)

[gadenbuie]

IMHO, it'd be great for the basic feature set to include drafting new R Markdown documents via package-provided templates. (The interface for doing this doesn't need to be as robust initially as RStudio's.)

[juliasilge]

Quarto is available on CRAN servers and we can advise folks to use Quarto for vignettes.

[jmcphers]

Bumping this to Future since I think we'll have to lean on the Quarto extension for R Markdown in the short term (and perhaps even for RC).

[juliasilge]

As outlined earlier in this issue, Quarto does provide some R Markdown functionality but doesn't use rmarkdown::render() for rendering. For many situations, we believe this will be acceptable, for example, generating a preview of README.Rmd or R package vignettes. (Note that we know the preview using Quarto will not be the same as, say, the final HTML vignettes as CRAN will render them.)

The remaining challenges around .Rmd are most dramatic for situations where you really do need rmarkdown::render(), like for custom R Markdown formats such as those outlined in #1471 (comment) and the following discussion. We could consider making a command in the R extension that literally uses rmarkdown::render() and then somehow renders a preview (using Quarto??? or we resolve #2559?) in the Viewer pane.

Note that even today folks do have the ability to run rmarkdown::render() from the console and then get their expected generated files. We are mostly talking about previews and UI affordances like keyboard shortcuts.

[kv9898]

I noticed that the Quarto support for Rmarkdown in Positron is no longer present, is this intentional? It seems that the positron-r extension is overriding Quarto for rmd documents.

I had to add the following to settings.json to make it work again:

"files.associations": {
        "*.rmd": "quarto",
    },

[juliasilge]

@kv9898 I am not able to reproduce that problem with the latest release (2024.11.0 build 69):

Can you check the details of what version you may be running? I suspect the problem is coming from another extension you have installed which is creating an association that is interfering with the Quarto support. I know, for example, there is a word count extension that creates a non-Quarto association for .Rmd which then means Quarto can't provide syntax highlighting or anything else.

[kv9898]

@kv9898 I am not able to reproduce that problem with the latest release (2024.11.0 build 69):

Can you check the details of what version you may be running? I suspect the problem is coming from another extension you have installed which is creating an association that is interfering with the Quarto support. I know, for example, there is a word count extension that creates a non-Quarto association for .Rmd which then means Quarto can't provide syntax highlighting or anything else.

I am using the word count extension! Thank you for looking this up. For now the fix I mentioned is working fine. I guess the extension only affects *.rmd but not *.qmd

[juliasilge]

It's because that extension (if it's the same one) says that an .Rmd file is rmarkdown and not quarto:

https://github.com/yunier-olivera/markdown-quarto-word-count/blob/4480749cb27e560d9bfb48fe8cbcd1c58043d931/package.json#L63

[kv9898]

It's because that extension (if it's the same one) says that an .Rmd file is rmarkdown and not quarto:

https://github.com/yunier-olivera/markdown-quarto-word-count/blob/4480749cb27e560d9bfb48fe8cbcd1c58043d931/package.json#L63

That makes a lot of sense! Thank you, @juliasilge.