Table of contents on xaringan slides? - xaringan

Question

I'm wondering whether it is possible to add a slide showing the table of contents into the document created with xaringan package? Thanks.

Answer 1

Update
Following lines will give you an automated Outline.
Unfortunately I do not know how to automatically reload an R script file in RStudio. If someone knows anything, please feel free to comment or answer in following Question.
The code searches for all the level 1 headers and the Outline header. Then it simply adds the headers as a list and overrides the current script. After reloading the file you have an outline.
---
```{r, echo=FALSE}
require("magrittr")
file_name <- rstudioapi::getSourceEditorContext()[["path"]]
doc <- toc <- readLines(file_name)
tocc <- character()
for (i in 1:length(toc)) {
if(substr(toc[i][1], 1, 2) == "# ") {
toc[i] <- gsub("# ", "", toc[i], fixed = TRUE) %>%
gsub("#", "", ., fixed = TRUE)
tocc <- append(tocc, toc[i])
}
}
tocc <- paste("- ", tocc[-1])
row_outline <- which(doc == "# Outline")
row_body <- which(doc == "---")
row_body <- row_body[which(row_body > row_outline)][1]
doc <- c(doc[1:row_outline], "\n", tocc, "\n", doc[(row_body):length(doc)])
writeLines(doc, file_name)
```
# Outline
---
Old Post
Since Sébastien Rochette's comment did not work for me, I created a very dirty solution with R.
I can think of much nicer solutions but this was a very quick solution. I hope I will update my answer in the near future.
---
```{r, echo=FALSE}
require("magrittr")
toc <- readLines("presentation.Rmd")
tocc <- character()
for (i in 1:length(toc)) {
if(substr(toc[i][1], 1, 2) == "# ") {
toc[i] <- gsub("# ", "", toc[i], fixed = TRUE) %>%
gsub("#", "", ., fixed = TRUE) %>%
paste0(" ", .)
tocc <- append(tocc, toc[i])
}
}
text <- paste(tocc[-1], "\n")
yy <- seq(.9, 0, length = length(text))
```
# Outline
```{r, echo = FALSE}
plot(x = rep(0.2, length(text)), y = yy * 1.035,
xlim = c(0, 1), ylim = c(-0.1, 1), xlab = "", ylab = "", axes = FALSE,
col = "#056EA7", type = "p", pch = 16)
text(x = 0.2, y = yy, labels = text, adj = 0, col = "black")
```
---