Preview of Rmarkdown

[Ikuyadeu]

Currently, the Markdown file can get a preview.
I believe R markdown file can also get a preview by calling preview command on Markdown.
I put this issue as the TODO

[andycraig]

By adding the below to settings.json, you can use Markdown: Open Preview on R markdown files. It doesn't do anything special with the R code blocks, though.

"files.associations": {
     "*.Rmd": "markdown"
}

From https://qiita.com/yutannihilation/items/1f71c0fedae6e4b8038c

[Ikuyadeu]

@andycraig Thank you! It is working well.

[Ikuyadeu]

I can not use R markdown syntax and inline execution by this change.
We should call Markdown: Open Preview as the R markdown mode.

[andycraig]

That's right, that change doesn't do anything special with R code blocks.

A better R markdown experience could be gained by adding a command that calls the knitr package, and then previews a resulting HTML or PDF file (maybe using https://marketplace.visualstudio.com/items?itemName=hdg.live-html-previewer and https://marketplace.visualstudio.com/items?itemName=tomoki1207.pdf). This could be a Good First Issue.

RStudio-like inline output from R code blocks would be tougher. I'm not sure if the VSCode editor supports non-text objects.

[andycraig]

It looks like the neuron extension might be very helpful here:

https://marketplace.visualstudio.com/items?itemName=neuron.neuron-IPE

I haven't managed to get it running successfully yet though, and it sounds like others are having trouble too: neuron-team/vscode-ipe#187

I've had more success with this fork:
https://marketplace.visualstudio.com/items?itemName=pavan.VSNotebooksBeta
It connects to Jupyter and displays the output of R code sent to it.

[andycraig]

Using VSNotebooks:

This setting was necessary to get VSNotebooks to recognise Rmd files:

"files.associations": {
    "*.Rmd": "r"
}

[RobJamesRamos]

Is this still being worked on? Rmarkdown support is one of the major reasons I don't switch to vscode.

[andycraig]

Hi @rjBadger, as shown in the video above, the VSNotebooksBeta extension (a fork of the neuron extension) provides some support of R Markdown files, although there is a lot of room for improvement. I'd like to see work on R Markdown support for VSCode made on neuron or one of its forks, so that the improvements also benefit Julia etc. I'm not currently working on anything related to this, though.

[andycraig]

There is an issue open for adding support for other languages to the (very good) Jupyter component of the Python extension. If you are interested in better notebook support for R, please consider voting for it here: https://github.com/microsoft/vscode-python/issues/5078#issuecomment-507751659

Thank you!

[renkun-ken]

With #150, we can use rmarkdown::run(file) to start an HTTP server to show an RMarkdown document, instantly.

[vnijs]

That sounds great @renkun-ken! Would this also allow to show chunks of text, math, and or code separately? For an illustration of what I mean, see the GIF below:

[adamaltmejd]

Would love to have a pdf preview option as well.

[eitsupi]

Now that R session watcher is enabled by default in #670, how about adding a button that runs rmarkdown::run(file) and opens a tab, like the button that shows the VSCode default Markdown preview?

[ElianHugh]

I wonder if it's possible to have run as a task, so that it's non-blocking. Hmm... Live preview would be very neat ;)

[ElianHugh]

I've tinkered with this idea a bit. A little proof of concept:

[renkun-ken]

There is an issue with rmarkdown::run() that mathjax and syntax highlight are lost when the document is refreshed. Didn't have time to investigate at the moment. @ElianHugh Are you interested in digging into this?

[ElianHugh]

Ah, I see what you mean - happy to look into it!

Edit:
A couple of observations:

• text decoration disappears when the shiny app refreshes the content, not when the page is refreshed manually. i.e., if auto_reload = FALSE, and you refresh the page, the decoration will still be there
• this issue is not specific to vscode-R, as I could replicate it in RStudio
• xaringan::inf_mr does not have this problem (although it is slower to load at times)

Syntax highlighting is maintained if a specific highlight theme is declared in the yaml, e.g.

---
title: "My R Doc"
output:
  html_document:
    highlight: kate
---

[ElianHugh]

Closed by #692.