Call rmarkdown::render interactively to create a preview version of a Rmd

render_preview.R

#' Call rmarkdown::render to create a preview version of a Rmd
#'
#' This function is intended to be used interactively to create a preview
#' version of a Rmd (e.g. compile a chapter of a bookdown project to docx).
#' By default, it renders the file currently opened in the RStudio source
#' editor, and saves the output to a subfolder called "preview".
#'
#' The default format is html. The argument word = TRUE will change the output
#' format to docx, and using pdf = TRUE will create PDF output.
#'
#' If docx output is to be created, the yaml header of the source document
#' should contain "always_allow_html: true". Due to the limitations of the file
#' format, do not expect complete or perfect output.
#'
#' For use in scripts, it is better to call rmarkdown::render directly
#'
#' @param file File to compile (Default: Use the rstudioapi package to specify the file currently opened in the source editor)
#' @param output_dir Output directory (Default: "preview")
#' @param format Output format (Default: html_document)
#' @param word Whether to change the output format to word_document
#' @param pdf Whether to change the output format to pdf_document
#'
#' @return Result of rmarkdown::render
#' @export
#'
render_preview <- function(file = rstudioapi::getSourceEditorContext()$path,
                           output_dir = "preview",
                           format = "html_document",
                           word = FALSE,
                           pdf = FALSE) {
  if (word) format <- "word_document"
  if (pdf) format <- "pdf_document"

  rmarkdown::render(
    input = file,
    output_dir = output_dir,
    output_format = format
  )
}