R/kaggle.R

In rawr: Retrieve Raw R Code from Popular Tutorials and Websites

#' Retrieve raw R code from a kaggle notebook
#'
#'
#' @name kaggle
#'
#' @usage kaggle(url, method, padding)
#'
#' @param url Link to a kaggle notebook
#' @param method Not all websites are formatted consistently. To overcome this, try a different
#'     method by setting the method
#'     parameter to integers 2 and greater to try other available methods
#' @param padding Specify what goes between the last character of one code block and the
#'     first character of the next code block. Default is a two new lines, which appears
#'     visually as one new line between code blocks.
#'
#' @return A character vector of length 1 containing the R code from the target url. Returned value
#'    will contain rmarkdown or python code if that was the language used in the kaggle notebook.
#'
#' @import dplyr jsonlite xml2
#' @importFrom rvest html_nodes html_text html_attr
#' @importFrom utils file.edit
#'
#' @export
#'
#' @examples
#' \donttest{
#' library(dplyr)
#' kaggle("https://www.kaggle.com/vrtjso/mercari-eda-more-info-than-you-can-imagine")
#' kaggle("https://www.kaggle.com/captcalculator/a-very-extensive-mercari-exploratory-analysis")
#' kaggle("https://www.kaggle.com/adityaecdrid/mnist-with-keras-for-beginners-99457")
#'
#' # Same as above but provided to cat for easy viewing
#'
#' # R
#' kaggle("https://www.kaggle.com/vrtjso/mercari-eda-more-info-than-you-can-imagine")  %>%
#'   cat
#'
#' # rmarkdown
#' kaggle("https://www.kaggle.com/captcalculator/a-very-extensive-mercari-exploratory-analysis") %>%
#'   cat
#'
#' # python
#' kaggle("https://www.kaggle.com/adityaecdrid/mnist-with-keras-for-beginners-99457") %>%
#'   cat
#' }


kaggle <- function(url, method, padding = "\n\n") {

glob <- xml2::read_html(url) %>%
  html_nodes(xpath = "//div[@data-component-name = 'KernelViewer']/following::script") %>%
  .[1] %>% html_text %>%
  strsplit(., "State.push\\(") %>% .[[1]] %>% .[2]  %>%
  strsplit(., "\\);performance && performance.mark && performance.mark\\(\"KernelViewer.componentCouldBootstrap\"\\);") %>%
  .[[1]] %>% .[1] %>% fromJSON


if(glob$kernelRun$language == "rmarkdown") {

  language <- "rmarkdown"
  code <- glob$kernelRun$commit$source %>%
    paste0(collapse=padding)
}else{

  source_code <- glob$kernelRun$commit$source %>% fromJSON

  language <- source_code$metadata$language_info$name
  list_indices_to_keep <- ifelse(source_code$cells$cell_type == "code", TRUE, FALSE)

  code <- source_code$cells$source[list_indices_to_keep] %>%
    lapply(function(x) { paste0(x, collapse="") }) %>%
    paste0(collapse=padding)

}

code
}