maybe_process: Process a File if Necessary
In macmillancontentscience/dlr: Download and Cache Files Safely

maybe_process

R Documentation

Process a File if Necessary

Description

Sometimes you just need to get a processed file to a particular location, without reading the data. For example, you might need to download a lookup table used by various functions in a package, independent of a particular function call that needs the data. This function does the processing if it hasn't already been done.

Usage

maybe_process(
  source_path,
  target_path,
  process_f = readRDS,
  process_args = NULL,
  write_f = saveRDS,
  write_args = NULL,
  force_process = FALSE
)

Arguments

`source_path`	Character scalar; the path to the raw file. Paths starting with `http://`, `https://`, `ftp://`, or `ftps://` will be downloaded to a temp file if the processed version is not already available.
`target_path`	Character scalar; the path where the processed version of the file should be stored.
`process_f`	A function or one-sided formula to use to process the source file. `source_path` will be passed as the first argument to this function. Defaults to `read_f`.
`process_args`	An optional list of additional arguments to `process_f`.
`write_f`	A function or one-sided formula to use to save the processed file. The processed object will be passed as the first argument to this function, and `target_path` will be passed as the second argument. Defaults to `base::saveRDS()`.
`write_args`	An optional list of additional arguments to `write_f`.
`force_process`	A logical scalar indicating whether we should process the source file even if the target already exists. This can be particularly useful if you wish to redownload a file.

Value

The normalized target_path.

Examples

if (interactive()) {
  temp_filename <- tempfile()
  maybe_process(
    "https://query.data.world/s/owqxojjiphaypjmlxldsp566lck7co",
    target_path = temp_filename,
    process_f = read.csv
  )

  unlink(temp_filename)
}

macmillancontentscience/dlr documentation built on Sept. 24, 2022, 12:50 p.m.