Files
hateimparlament/R/fetch.R
T

64 lines
1.9 KiB
R

mk_absolute_url <- function(path) paste0("https://www.bundestag.de", path)
mk_url <- function(offset) {
mk_absolute_url %$% sprintf("/ajax/filterlist/de/services/opendata/543410-543410?offset=%d",
offset)
}
download_protocol <- function(path, name, download_dir) {
fp <- paste0(download_dir, name)
try %$% download.file(mk_absolute_url(path), fp, quiet=T)
progress <<- progress + 1
setTimerProgressBar(pb, progress)
}
fetch_batch <- function(offset, download_dir) {
stopifnot("Offset must be numeric" = is.numeric(offset))
mk_url(offset) %>%
rvest::read_html() %>%
as.character() %>%
str_match_all("/resource/blob/.*?/([0-9]*-data\\.xml)") %>%
`[[`(1) ->
paths
mapply(download_protocol,
paths[,1],
paths[,2],
MoreArgs=list(download_dir = download_dir))
return(length(paths) > 0)
}
# TODO: error handling
# - what if: page not reachable
# - wrong format, etc.
#' Download available records
#'
#' This fetches all available records of the 19th legislative period of the german Bundestag.
#'
#' @param download_dir character
#' @param create bool
#'
#' if create is TRUE, the directory given in download_dir is created
#'
#' @export
fetch_all <- function(download_dir="inst/records/", create=FALSE) {
# append file separator if needed
download_dir <- make_directory_path(download_dir)
check_directory(download_dir, create)
cat("Fetching all available records from bundestag.de. This may take a while ...\n")
# create progress bar
pb <<- timerProgressBar(min=0, max=250, width=40, char="+")
progress <<- 0
# close progress bar on exit (also on error)
on.exit({close(pb); cat("Done.\n")})
# fetch batch by batch
offset <- 0
while(fetch_batch(offset, download_dir)) offset <- offset + 10
# if successful, set progressbar to 100%
setTimerProgressBar(pb, 250)
}