Register and dispatch file readers

Register and dispatch file readers

Usage

registerReader(format, fn, ext = NULL, overwrite = FALSE)

getReader(format)

availableReaders()

unregisterReader(format)

Arguments

format

Case-insensitive format key (e.g. "brainvision").

fn

The reader function; its first argument should be a file path.

ext

Optional character vector of file extensions handled (no dot).

overwrite

If FALSE (default), registering an existing format errors; TRUE replaces it (use this in a package .onLoad).

Value

registerReader() invisibly returns fn; getReader() returns the registered function; availableReaders() returns a data.frame of format/ext (the format column holds normalized, lower-cased keys, and the frame has zero rows when nothing is registered); unregisterReader() invisibly returns TRUE if a reader was removed.

See also

Other plugin-api: physio-registry, registerOperation(), registerWriter()

Examples

registerReader("demo_csv", function(file, ...) read.csv(file, ...),
               ext = "csv", overwrite = TRUE)
availableReaders()
#>     format ext
#> 1 demo_csv csv
r <- getReader("DEMO_CSV")   # case-insensitive
unregisterReader("demo_csv")