wrap text in knitr::kable table cell using "\n"

Question

How can I wrap a cell in a knitr::kable table cell using \n?

---

I want to generate a .rmd file containing some tables where one column needs text wrapping. The places where the wrapping should occur are marked with \n. I tried (this is a standalone .rmd document):

---
output: pdf_document
---

## A Table with text wrap

```{r cars}
knitr::kable(data.frame(col1 = c("a", "b"), col2 = c("one\ntwo", "three\nfour")))
```

..but this doesn't work. Instead of staying in col2, the wrapped part lives on the next line of col1.

Expected output is:

col1 | col2
-------------
a    | one
     | two
b    | three
     | four

Solutions using other packages than knitr are welcome as long as they allow to print (nearly) as nice.

Answer 1

A fire-and-forget solution for flexible dual HTML/PDF of standard tables. It incorporates kableExtra's linebreak function outlined by @snoram.
Assumption: You use <br> as your line break indicator.

```{r}
knit_table(df1)
```

Code

library(dplyr)
library(knitr)
library(kableExtra)

knit_table <- function(df){
  if (is_html_output()) {
    df %>%
      kable("html", escape = F) %>%
      kable_styling()
  } else {
    df <- data.frame(lapply(df, function(x) {gsub("<br>", "\n", x)}), stringsAsFactors = F)

    df %>%  
      mutate_all(linebreak) %>%
      kable("latex", booktabs = T, escape = F)  
  }
}

Data

df1 <- data.frame(col1 = c("a", "b"),
                  col2 = c("one<br>two", "three<br>four"))

Answer 2

If you don't mind using kableExtra you can definitely achieve this, here is one example:

library(kableExtra)
knitr::kable(data.frame(col1 = c("a", "b"), col2 = linebreak(c("one\ntwo", "three\nfour"))),
             escape = FALSE)

More details here.