Extra yaml emitted when a function calls knitr::asis_output

[harrelfe]

I am writing a function that can be called several times within one code chunk. It takes constructed HTML and wraps it in knitr::asis_output() so that I don't need to remember to put results='asis' in the chunk header. The output is rendered correctly when running Quarto. But I'm getting these two lines surrounding the rendered HTML:

::: {.cell-output-display}
::::

These extra lines are appearing verbatim in the finished Quarto HTML report.

🆕 I think the constructed HTML that triggers the problem contains <style>, <div>, <span>.

Any ideas what is causing this and how to prevent it? Thanks in advance. The little function that calls asis_output given a string x of HTML appears below.

rendHTML <- function(x) {
  x <- paste0('\n', paste(x, collapse='\n'), '\n')
  if(length(getOption('knitr.in.progress'))) {
    return(knitr::asis_output(x))
    }
  print(htmltools::browsable(htmltools::HTML(x)))
}

See also https://stackoverflow.com/questions/75353004

[cscheid]

Those lines are not yaml. That's a markdown div, and it's generated (on purpose) if your cell doesn't contain results='asis'.

That markdown div should be getting converted to a div by Pandoc. Have you tried wrapping your raw HTML in

```{=html}
put-your-raw-html-here
```

instead of simply emitting the HTML output?

[cscheid]

Can you try emitting

```{=html}

at the beginning of that block, and

```

at the end?

Like so:

---
title: "Test"
format:
  html:
    self-contained: true
---


````{r}
x <- '
```{=html}
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<style>
.earrows {color:silver;font-size:11px;}

fcap {
 font-family: Verdana;
 font-size: 12px;
 color: MidnightBlue
 }

smg {
 font-family: Verdana;
 font-size: 10px;
 color: &#808080;
}

hr.thinhr { margin-top: 0.15em; margin-bottom: 0.15em; }

span.xscript {
position: relative;
}
span.xscript sub {
position: absolute;
left: 0.1em;
bottom: -1ex;
}
</style>
 <title>stage Descriptives</title> <font color="MidnightBlue"><div align=center><span style="font-weight:bold">stage <br><br> 1  Variables   502  Observations</span></div></font> <hr class="thinhr"> <span style="font-weight:bold">stage</span>: Stage <style>
 .hmisctable468037 {
 border: none;
 font-size: 85%;
 }
 .hmisctable468037 td {
 text-align: center;
 padding: 0 1ex 0 1ex;
 }
 .hmisctable468037 th {
 color: MidnightBlue;
 text-align: center;
 padding: 0 1ex 0 1ex;
 font-weight: normal;
 }
 </style>
 <table class="hmisctable468037">
 <tr><th>n</th><th>missing</th><th>distinct</th><th>Info</th><th>Mean</th><th>Gmd</th></tr>
 <tr><td>502</td><td>0</td><td>2</td><td>0.733</td><td>3.424</td><td>0.4895</td></tr>
 </table>
 <pre style="font-size:85%;">
 Value          3     4
 Frequency    289   213
 Proportion 0.576 0.424
 </pre>
 <hr class="thinhr">
```'
knitr::asis_output(x)
````

[cscheid]

The problem with the HTML you're emitting is that it confuses Pandoc's HTML reader. By wrapping it in

```{=html}
your-html-here
```

Pandoc will not attempt to parse your HTML as AST elements and get confused. Generally speaking, if you're in the business of emitting raw HTML, it pays off to use that syntax I suggested (unless you know precisely what you're doing and that it's safe).

[harrelfe]

That did it! I'll try that now on the bigger test with dynamically emitted html.

[harrelfe]

The big test is working well. You're the best!

[cscheid]

Glad to be of help!

[cderv]

I am adding context based on the discussion and solution I am seing above.

You shared your function was

rendHTML <- function(x) {
  x <- paste0('\n', paste(x, collapse='\n'), '\n')
  if(length(getOption('knitr.in.progress'))) {
    return(knitr::asis_output(x))
    }
  print(htmltools::browsable(htmltools::HTML(x)))
}

I believe the existing HTML and R Markdown toolchain can do the right think for you without needing to add the raw attribute yourself and all like solution above.

Doing the following should work ok in knitr

rendHTML <- function(x) {
  x <- paste0('\n', paste(x, collapse='\n'), '\n')
  htmltools::browsable(htmltools::HTML(x))
}

When a code is run in knitting, the output will be processed by some specific knit_print() method (and not print()). More on that in https://cran.r-project.org/web/packages/knitr/vignettes/knit_print.html
When not running in knitr, the printing of your function result will be with print()

htmltools defines a knit_print.html method that will do

• the HTML protecting for you adding the ```{=html}
• output using knitr::asis_output()

So you should not need anything specific than using htmltools .

Also FWIW, there is a knitr::raw_html() function that one can use to add the raw code attributes for Pandoc.

Try that

---
title: raw HTML
format: html
---
    
```{r}
rendHTML <- function(x) {
  x <- paste0('\n', paste(x, collapse='\n'), '\n')
  htmltools::browsable(htmltools::HTML(x))
}
```


```{r}
rendHTML("<div>\ncontent\n</div>")
```

Hope it helps understand how this works