source all r files in a gist

source_gist_all.R

library(getPass)
library(httr)
library(rvest)

#' source_gist_all
#' 
#' Standalone replacement for \code{devtools::source_gist} which
#' sources all the R files in a github gist with 
#' authentication and error handling.
#' I didn't replicate any of the individual file-level 
#' features of \code{devtools::source_gist} like hash matching
#' because those don't apply as much when sourcing multiple files.
#' 
#' @param id character gist id or url
#' @param user character github username
#' @param pass character github password
#'
#' @import getPass httr rvest
#' @export
#' 
source_gist_all <- function(id="7b07ee41e42791c7d61b145487d62037", user=NULL, pass=NULL) {
  
  if (!grepl("github.com", id)) {
    id <- paste0("https://gist.github.com/", id)
  }
  
  if (is.null(user)) {
    user <- getPass::getPass("github user: ")
  }
  
  if (is.null(pass)) {
    pass <- getPass::getPass("github pass: ")
  }

  res <- httr::GET(id, httr::authenticate(user, pass))
  doc <- xml2::read_html(res)
  nodes <- rvest::html_nodes(doc, css = "a")
  links <- rvest::html_attr(nodes , "href")
  matches <- grepl("\\.(r|R)$", links)
  r_files <- as.character(links[matches])
  
  for (i in 1:length(r_files)) {
    url <- paste0("https://gist.github.com", r_files[i])
    res <- httr::GET(url, httr::authenticate(user, pass))
    if (httr::http_error(res)) {
      stop("Authenticated Request Failed... \nCheck Your Credentials")
    }
    text <- httr::content(res)
    fun_text <- tryCatch(parse(text = text), error = function(e) e)
    if ("expression" %in% class(fun_text)) {
      message(paste("sourcing file:", basename(as.character(r_files[i]))))
      eval(fun_text, envir = parent.frame())
    }
  } 
  
}