Xaringan: Infinite moon reader

[fmmattioni]

I am not quite sure whether this is a bug. It seems that when you set seal: false and the first slide becomes your first slide, if there is a --- before this slide the instant preview won't work.

Here is an example:

https://github.com/rstudio-education/arm-workshop-rsc2019/blob/master/static/slides/xaringan.Rmd#L38

When this line is excluded, then the preview works.

[fmmattioni]

Quick reprex:

No good (with layout: true and --- before first slide):

title: "Presentation Ninja"
subtitle: "⚔<br/>with xaringan"
author: "Yihui Xie"
date: "2016/12/12 (updated: `r Sys.Date()`)"
output:
  xaringan::moon_reader:
    lib_dir: libs
    nature:
      highlightStyle: github
      highlightLines: true
      countIncrementalSlides: false
    seal: false
---

layout: true

---
class: center, middle

# xaringan

### /ʃaː.'riŋ.ɡan/

---
class: inverse, center, middle

# Get Started

If we remove --- between layout and class then it works again.

[yihui]

Should be fixed now. Thanks for the report! Please test the development version via

remotes::install_github('yihui/xaringan')

[fmmattioni]

Cool! Thanks for taking a look into that!

[fmmattioni]

Just tested it out and it is working great! Thanks for that!

[fmmattioni]

I might have found another bug by mistake. I wanted to use incremental slides inside a .pull-left[] and .pull-right[] - which btw I am not sure if it is possible (at least I couldn't get it to work), but anyways... The thing is that if I have a -- inside .pull-left[] or .pull-right[] the instant preview doesn't work anymore.

I am also not sure if this is a bug. But I thought it would be worth it to mention (please, let me know if I should open a new issue).

Reprex:

title: "Presentation Ninja"
subtitle: "⚔<br/>with xaringan"
author: "Yihui Xie"
date: "2016/12/12 (updated: `r Sys.Date()`)"
output:
  xaringan::moon_reader:
    lib_dir: libs
    nature:
      highlightStyle: github
      highlightLines: true
      countIncrementalSlides: false
    seal: false
---

# Hello World

.pull-left[
Install the **xaringan** package from [Github](https://github.com/yihui/xaringan)
]

--

.pull-right[

You are recommended to use the [RStudio IDE](https://www.rstudio.com/products/rstudio/), but you do not have to.

- Create a new R Markdown document from the menu `File -> New File -> R Markdown -> From Template -> Ninja Presentation`;<sup>1</sup>

--

- Click the `Knit` button to compile it;

]

Note the -- between - Create... and - Click.... As soon as you remove it, the instant preview works again.

> sessionInfo()
R version 3.5.3 (2019-03-11)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 18.04.2 LTS

Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.7.1
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.7.1

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=de_DE.UTF-8        LC_COLLATE=en_US.UTF-8    
 [5] LC_MONETARY=de_DE.UTF-8    LC_MESSAGES=en_US.UTF-8    LC_PAPER=de_DE.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=de_DE.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.0        later_0.8.0       compiler_3.5.3    prettyunits_1.0.2 remotes_2.0.2     tools_3.5.3      
 [7] testthat_2.0.1    digest_0.6.18     packrat_0.5.0     pkgbuild_1.0.2    pkgload_1.0.2     jsonlite_1.6     
[13] memoise_1.1.0     evaluate_0.13     rlang_0.3.1       cli_1.0.1         rstudioapi_0.9.0  yaml_2.2.0       
[19] xfun_0.5.2        withr_2.1.2       stringr_1.4.0     knitr_1.22        desc_1.2.0        htmlwidgets_1.3  
[25] fs_1.2.6          devtools_2.0.1    rprojroot_1.3-2   DT_0.5            glue_1.3.1        R6_2.4.0         
[31] processx_3.3.0    rmarkdown_1.12    xaringan_0.9.2    sessioninfo_1.1.1 callr_3.1.1       magrittr_1.5     
[37] servr_0.13.1      promises_1.0.1    backports_1.1.3   ps_1.3.0          htmltools_0.3.6   usethis_1.4.0    
[43] assertthat_0.2.0  httpuv_1.4.5.1    stringi_1.4.3     crayon_1.3.4     

[yihui]

It is not a bug. You cannot break .anything[ ] in the middle using --. Or in general, -- shouldn't be used to break an element into two syntactically incomplete elements. You can break lists, paragraphs, and quotes, etc., but neither .foo[bla bla or bla bla] is syntactically complete, so

.foo[bla bla
--
bla bla]

won't work.

[fmmattioni]

Oooh, ok! Thanks for the quick response!