R/01_quickmd.R

In moodymudskipper/mmmd: Tools for quick markdown reports

#' Quick Markdown Report
#'
#' Create a markdown report from a list of instructions.
#'
#' @param ... instructions, character will be converted to text and headers,
#' formulas will be converted to chunks, optional lhs of formula is a list of
#' chunk options.
#' @param output_file path of output, optional
#' @param header YAML header, given as a list fed to `yaml::as.yaml`
#' @param open if `TRUE` (default), report will be opened after creation
#'
#' @return the path of the output file
#' @export
#'
#' @examples
#' library(tidyr)
#' x <- iris %>% nest(-Species)
#'
#' # create report on the fly
#' quickmd(
#'   "# Plot of {x$Species[1]}",
#'   "{x$Species[1]} has a mean petal length of {mean(x$data[[1]]$Petal.Length)}",
#'   ~ hist(x$data[[1]]$Sepal.Width),
#'   .(fig.height=3) ~ hist(x$data[[1]]$Sepal.Length))
#'
#' # create report from a list of instructions
#' dots <- list("# Plot of {x$Species[1]}",
#'              "{x$Species[1]} has a mean petal length of {mean(x$data[[1]]$Petal.Length)}",
#'              ~hist(x$data[[1]]$Sepal.Width),
#'              list(fig.height=3) ~ hist(x$data[[1]]$Sepal.Length))
#'
#' quickmd(!!!dots)
quickmd <- function(
  ...,
  output_file = NULL,
  header = list(
    title = "mmmd report",
    author = Sys.getenv("USERNAME"),
    date = "`r Sys.Date()`",
    output = list(html_document = list(code_folding = "hide"))),
  open = TRUE){
  if (!is.data.frame(x)) stop("x must be a data.frame")
  dots <- tibble::lst(...)
  body <- purrr::map_chr(dots,~purrr::when(
    .,
    is.character(.)       ~ glue::glue(.),
    inherits(.,"formula") ~ formula_to_chunk(.))) %>%
    paste(collapse = "\n\n")

  chr <- glue::glue("---\n{as.yaml(header)}---\n\n{body}")
  temp_rmd <- tempfile(fileext = ".Rmd")
  write(chr,temp_rmd)
  output_file <- rmarkdown::render(temp_rmd, output_file = output_file)
  if (open) browseURL(output_file)
  output_file
}