Unable to load image of type pdf

[ssp3nc3r]

An image of type pdf does not display on a slide either when using

knitr::include_graphics()

or markdown,

![]()

Here's an example:

---
title: "Untitled"
output: 
  revealjs::revealjs_presentation: default
---

# Slide with Plot

```{r, echo=FALSE}
pdf("myplot.pdf")
plot(x = 1:10, y = 1:10)
dev.off()
```

# load image using knitr

```{r}
knitr::include_graphics("myplot.pdf")
```

# load image using markdown

![](myplot.pdf)

Here's information from xfun::session_info('revealjs') my session?

R version 4.1.2 (2021-11-01)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Monterey 12.1, RStudio 2021.9.1.372

Locale: en_US.UTF-8 / en_US.UTF-8 / en_US.UTF-8 / C / en_US.UTF-8 / en_US.UTF-8

Package version:
  base64enc_0.1.3     digest_0.6.29       evaluate_0.14       fastmap_1.1.0       glue_1.6.0         
  graphics_4.1.2      grDevices_4.1.2     highr_0.9           htmltools_0.5.2     jquerylib_0.1.4    
  jsonlite_1.7.2      knitr_1.37          magrittr_2.0.1      methods_4.1.2       revealjs_0.9.1.9007
  rlang_0.4.12        rmarkdown_2.11      stats_4.1.2         stringi_1.7.6       stringr_1.4.0      
  tinytex_0.36        tools_4.1.2         utils_4.1.2         xfun_0.29           yaml_2.2.1  

I've upgraded all packages and tested the issue on the development version.

[cderv]

Thanks for the report. It seems like and issue with Pandoc

Using

❯ echo "![](myplot.pdf)" | pandoc -t revealjs
<section class="slide level6">

<p><embed data-src="myplot.pdf" /></p>
</section>

❯ echo "![](myplot.pdf)" | pandoc -t html
<p><embed src="myplot.pdf" /></p>

<embed> needs a src attribute and not a data-src. The latter is used for revealjs and this make the element not work.

It could be a special treatment by revealjs for Lazy Loading but it does not seem to work for embed element.
https://github.com/hakimel/reveal.js/blob/f7c59649fe9d72a148860220a66511cefd142907/js/controllers/slidecontent.js#L52-L59

[cderv]

I have opened an issue in Pandoc jgm/pandoc#7830