RMarkdown: bookdown with plotly

Question

I'm using the bookdown package with RMarkdown to generate web-based book similar to this, likewise with the option to download a pdf-version of the book.

I've included plotly graphs in my "book" which work nicely in the html-version of the book. Being interactive, the button "build book" throws an error when including pdf output in the YAML-header.

Based on this description I've found a workaround with a regular RMarkdown File to create pdfs with plotly graphs outputs. A minimal solution (outside bookdown) looks like this:

---
title: "test"
output:
  pdf_document: default
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
library(plotly)

Sys.setenv("plotly_username" = "username")
Sys.setenv("plotly_api_key" = "API")
```


```{r cars}
library(plotly)
p <- plot_ly(x = c(1,2,3,4), y = c(2,4,1,3), type = 'scatter', mode = 'lines')
plotly_IMAGE(p, format = "png", out_file = "output.png")

```
![Caption for the picture.](output.png)

Is there a way to include this solution within bookdown, so that the graphs are automagically interactive in the html output and static (png) in the pdf output?

Answer 1

Based on this blogpost I was able to come up with a solution. Note, this only works

• with the "knitr" button (see this post for a workaround)
• with an internet connection (1) and Plotly Account (2)

(1) See this link to export static images locally (which I didn't get to work since I failed installing PhantomJS)

(2) Plotly has a user Quota of currently 100 plots / grids per user per day

---
title: "test"
output:
  html_document: default
  pdf_document: default
  word_document: default
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
library(plotly)
library(pander)
Sys.setenv("plotly_username" = "YOUR PLOTLY USERNAME")
Sys.setenv("plotly_api_key" = "API KEY")

output <- knitr::opts_knit$get("rmarkdown.pandoc.to") # html / latex / docx

```


```{r, results="asis"}

print(output)

p <- plot_ly(x = c(1,2,3,4), y = c(2,4,1,3), type = 'scatter', mode = 'lines')

filename <- "output.png"

if(output %in% c("latex","docx")){
  plotly_IMAGE(p, format = "png", out_file = filename)
  pandoc.image(filename)
} else if(output == "html"){
  p
} else(print("No format defined for this output filetype"))


```