R/scrape_ats.R

In Huh/CollarDownloadeR: Automate downloading of telemetry data from manufacturer's websites

#' Scrape data from ATS website
#'
#' @param bttn_nm The name of the button to download data from
#' @param usr The username associated with the account
#' @param pwd The password used with the supplied username
#'
#' @details The url where the function attempts to gain access is atsidaq.net.
#'
#' To download from a new button name use the developer tools in your browser and record the name of the button as described there.  For example, the download all button has CSS name 'ctl00$ContentPlaceHolder1$DownloadAll3'.
#' @return A tibble with automatic parsing of column types
#' @export
#'
#' @examples scrape_ats(usr = "my_username", pwd = "secret_code")
scrape_ats <- function(bttn_nm = NULL, usr = NULL, pwd = NULL){

    if(is.null(bttn_nm)){
      warning("Button name NULL, downloading all data")
    }
    stopifnot(!is.null(usr))
    stopifnot(!is.null(pwd))

    base_url <- "atsidaq.net"

    #  Connect to webpage
    pgsession <- rvest::html_session(base_url)
    httr::stop_for_status(pgsession)

    #  Extract html form
    pgform <- rvest::html_form(pgsession)[[1]]

    #  Fill in username and password
    filled_form <- rvest::set_values(
      pgform,
      'txt_username' = usr,
      'txt_password' = pwd
    )

    # "click" login button
    dwnld_form <- rvest::submit_form(pgsession, filled_form) %>%
      xml2::read_html(.) %>%
      rvest::html_form(.)

    # Which button to download data from?
    if(is.null(bttn_nm)){
      bttn_nm <- "ctl00$ContentPlaceHolder1$DownloadAll3"
    }

    #  "Click" button to download data and then parse the response
    dat_dwnld <- rvest::submit_form(
      pgsession,
      dwnld_form[[1]],
      submit = bttn_nm
    )

    httr::stop_for_status(dat_dwnld)

    out <- httr::content(dat_dwnld$response, type = "text/csv")

return(out)
}