insert portions of a markdown document inside another markdown document using knitr

Question

I know this can be done with php and other languages, but was wondering whether the following could be accomplished using knitr:

Let\'s say I have an Rmarkdown (.rmd

Answer 1

1. that is what the chunk option child is for, e.g. in second.Rmd, you can

   ```{r child='first.Rmd'}
   ```
   

2. that is a little bit trickier, but you can call knit_child() manually, e.g.

   ```{r echo=FALSE, results='asis'}
   # knit the first three lines of first.Rmd
   cat(knit_child(text = readLines('first.Rmd')[1:3]), sep = '\n')
   ```