Download a remote file

downloadRemote(
  url,
  archive,
  targetFile,
  checkSums,
  dlFun = NULL,
  fileToDownload,
  messSkipDownload,
  destinationPath,
  overwrite,
  needChecksums,
  .tempPath,
  preDigest,
  alsoExtract = "similar",
  verbose = getOption("reproducible.verbose", 1),
  ...
)

Arguments

url: Optional character string indicating the URL to download from. If not specified, then no download will be attempted. If not entry exists in the CHECKSUMS.txt (in destinationPath), an entry will be created or appended to. This CHECKSUMS.txt entry will be used in subsequent calls to prepInputs or preProcess, comparing the file on hand with the ad hoc CHECKSUMS.txt. See table in preProcess().
archive: Optional character string giving the path of an archive containing targetFile, or a vector giving a set of nested archives (e.g., c("xxx.tar", "inner.zip", "inner.rar")). If there is/are (an) inner archive(s), but they are unknown, the function will try all until it finds the targetFile. See table in preProcess(). If it is NA, then it will not attempt to see it as an archive, even if it has archive-like file extension (e.g., .zip). This may be useful when an R function is expecting an archive directly.
targetFile: Character string giving the filename (without relative or absolute path) to the eventual file (raster, shapefile, csv, etc.) after downloading and extracting from a zip or tar archive. This is the file before it is passed to postProcess. The internal checksumming does not checksum the file after it is postProcessed (e.g., cropped/reprojected/masked). Using Cache around prepInputs will do a sufficient job in these cases. See table in preProcess().
checkSums: TODO
dlFun: Optional "download function" name, such as "raster::getData", which does custom downloading, in addition to loading into R. Still experimental.
fileToDownload: TODO
messSkipDownload: The character string text to pass to messaging if download skipped
destinationPath: Character string of a directory in which to download and save the file that comes from url and is also where the function will look for archive or targetFile. NOTE (still experimental): To prevent repeated downloads in different locations, the user can also set options("reproducible.inputPaths") to one or more local file paths to search for the file before attempting to download. Default for that option is NULL meaning do not search locally.
overwrite: Logical. Should downloading and all the other actions occur even if they pass the checksums or the files are all there.
needChecksums: Logical indicating whether to generate checksums. ## TODO: add overwrite arg to the function?
.tempPath: Optional temporary path for internal file intermediate steps. Will be cleared on.exit from this function.
preDigest: The list of preDigest that comes from CacheDigest of an object
alsoExtract: Optional character string naming files other than targetFile that must be extracted from the archive. If NULL, the default, then it will extract all files. Other options: "similar" will extract all files with the same filename without file extension as targetFile. NA will extract nothing other than targetFile. A character string of specific file names will cause only those to be extracted. See table in preProcess().
verbose: Numeric, -1 silent (where possible), 0 being very quiet, 1 showing more messaging, 2 being more messaging, etc. Default is 1. Above 3 will output much more information about the internals of Caching, which may help diagnose Caching challenges. Can set globally with an option, e.g., options('reproducible.verbose' = 0) to reduce to minimal
...: Additional arguments passed to postProcess() and Cache(). Since ... is passed to postProcess(), these will ... will also be passed into the inner functions, e.g., cropInputs(). Possibly useful other arguments include dlFun which is passed to preProcess. See details and examples.