I'm working with the R package slidify to create revealjs slides. I'd like to reveal code fragments incrementally using the RMarkdown (rather than edit the resulting HTML) but can't seem to figure out a way.
In the example below I have two code chunks and I'd like the second to occur only after the preceding paragraph. I can go in to the resulting HTML and add class=fragment to the pre tag, but this is very inefficient!
Suggestions
---
title : RevealJS with Bootstrap
framework : revealjs
---
```{r}
mean(1:3)
```
<div class="fragment">
This works fine, the div does not appear until you click forward in the deck. But you can't put the div tags around a code fragment.
</div>
```{r}
mean(1:3)
```
You might have already answered for yourself by now, but one solution would be using knitr hooks. Here is a simple example:
---
title : RevealJS with Bootstrap
framework : revealjs
---
```{r cache=F,echo=F}
s0 <- knitr::knit_hooks$get('source')
o0 <- knitr::knit_hooks$get('output')
knitr::knit_hooks$set(
list(
source=function(x,options){
if (is.null(options$class)) s0(x, options)
else
paste0(
paste0("<div class='", options$class, "'><pre><code>")
,x
,'</code></pre>\n'
)
}
,output = function(x,options){
if (is.null(options$class)) o0(x, options)
else
paste0(
"<pre><code>"
,x
,'</code></pre></div>\n'
)
}
)
)
```
```{r class="fragment"}
mean(1:3)
```
<div class="fragment">
This works fine, the div does not appear until you click forward in the deck. But you can't put the div tags around a code fragment.
</div>
```{r class="fragment"}
mean(1:3)
```