metabodecon (version 1.6.2)

datadir: Return path to metabodecon's data directory

Description

Returns the path to the directory where download_example_datasets() stores metabodecon's example data sets or any file within that directory. By default this directory is a subdirectory of R's temporary session directory. If persistent is set to TRUE, the directory equals the data directory returned by tools::R_user_dir() instead.

Usage

datadir(file = NULL, warn = TRUE, persistent = NULL)

Value

Path to the data directory or a file within it.

Arguments

file

Relative path to a file within the data directory.

warn

Print a warning message when the requested path does not yet exist?

persistent

Return the path to the persistent data directory instead of the temporary one?

Author

2024-2025 Tobias Schmidt: initial version.

Details

The decision to use a temporary data dir as default and a persistent one only optionally was made to conform to CRAN package policies, which state that:

Packages should not write in the user's home filespace (including clipboards), nor anywhere else on the file system apart from the R session's temporary directory [...] Limited exceptions may be allowed in interactive sessions if the package obtains confirmation from the user. For R version 4.0 or later [...] packages may store user-specific data, configuration and cache files in their respective user directories obtained from tools::R_user_dir() [...].

Source: cran.r-project.org/web/packages/policies.

See Also

download_example_datasets(), datadir_persistent(), datadir_temp()

Examples

# Get temporary datadir and persistent datadir
datadir(persistent = FALSE, warn = FALSE)
datadir(persistent = TRUE,  warn = FALSE)

# Get persistent datadir if existing else temp datadir. Set `warn = TRUE`
# to raise a warning if none of the directories exist yet.
datadir(warn = FALSE)
if (interactive()) datadir()

# Get PERSISTENT_DATADIR/bruker if existing else TEMP_DATADIR/bruker
datadir(file = "bruker/urine", warn = FALSE)