Using markdown in flextable caption - r

Question

I want to use bold and italics in a flextable caption. I know that it is possible to apply font syles to text within the header or body of a flextable using the ftExtra package and one can choose different output styles for a caption in word output by officeR. But either these do not work with the caption (ftExtra) or do not provide a style that allows selective application of bold and italics.
Here is some code with the intended markdown in the caption:
library(flextable)
library(dplyr)
iris[1:10,] %>%
flextable() %>%
set_caption(caption = "**Tab. 1:** First ten (*n* = 10) samples of the Iris species dataset")
The caption should read as "Tab. 1: First ten (n = 10) samples of the Iris species dataset"
UPDATE
based on the comment by dario a possible solution would be:
library(flextable)
library(dplyr)
iris[1:10,] %>%
flextable() %>%
add_header_lines("") %>%
compose(
i = 1, part = "header",
value = as_paragraph(
as_chunk("Table 1: ", props = fp_text(bold = TRUE)),
as_chunk("First ten ("),
as_chunk("n", props = fp_text(italic = TRUE)),
as_chunk(" = 10) samples of the Iris species dataset")
)
)
Thank you very much. In the end I need to produce about 20 tables in different chapters and so I will try the suggestion by David to build the captions during knitting a markdown. But it is good to know that there is way, although clunky and not flexible using compose.

Answer 1

I prepared a markdown template for you:
---
title: "Hello World"
header-includes:
- \usepackage{caption}
output:
pdf_document:
latex_engine: xelatex
---
```{r, include = FALSE}
library(flextable)
library(dplyr)
table2 <- flextable(mtcars[1:5, 1:6])
```
This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.
When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:
\begin{table}[hbtp]
\captionof{table}{Text of the caption.}
`r table2`
\end{table}
This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.
When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:
An output