read_or_process: Read or Process a File
In dlr: Download and Cache Files Safely

Description Usage Arguments Value Examples

Often, a file must be processed before being usable in R. It can be useful to save the processed contents of that file in a standard format, such as RDS, so that the file does not need to be processed the next time it is loaded.

read_or_process(
  source_path,
  target_path,
  process_f = readRDS,
  process_args = NULL,
  read_f = readRDS,
  read_args = NULL,
  write_f = saveRDS,
  write_args = NULL,
  force_process = FALSE
)

`source_path`	Character scalar; the path to the raw file. Paths starting with `http://`, `http://`, `http://`, or `http://` 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`.
`read_f`	A function or one-sided formula to use to read the processed file. `target_path` will be passed as the first argument to this function. Defaults to `readRDS`.
`read_args`	An optional list of additional arguments to `read_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 `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.

The processed object.

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

# Calling the function a second time gives the result instantly.
if (interactive()) {
  austin_smoke_free <- read_or_process(
    "https://query.data.world/s/owqxojjiphaypjmlxldsp566lck7co",
    target_path = temp_filename,
    process_f = read.csv
  )
  head(austin_smoke_free)
}

if (interactive()) {
  # Remove the generated file.
  unlink(temp_filename)
}