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Set configuration settings.

Source: R/tar_config_set.R
tar_config_set.Rd

tar_config_set() writes special custom settings for the current project to an optional YAML configuration file.

Usage

tar_config_set(
  inherits = NULL,
  reporter_make = NULL,
  reporter_outdated = NULL,
  store = NULL,
  shortcut = NULL,
  script = NULL,
  workers = NULL,
  config = Sys.getenv("TAR_CONFIG", "_targets.yaml"),
  project = Sys.getenv("TAR_PROJECT", "main")
)

Arguments

inherits

Character of length 1, name of the project from which the current project should inherit configuration settings. The current project is the project argument, which defaults to Sys.getenv("TAR_PROJECT", "main"). If the inherits argument NULL, the inherits setting is not modified. Use tar_config_unset() to delete a setting.

reporter_make

Character of length 1, reporter argument to tar_make() and related functions that run the pipeline. If the argument NULL, the setting is not modified. Use tar_config_unset() to delete a setting.

reporter_outdated

Character of length 1, reporter argument to tar_outdated() and related functions that do not run the pipeline. If the argument NULL, the setting is not modified. Use tar_config_unset() to delete a setting.

store

Character of length 1, path to the data store of the pipeline. If NULL, the store setting is left unchanged in the YAML configuration file (default: _targets.yaml). Usually, the data store lives at _targets. Set store to a custom directory to specify a path other than _targets/. The path need not exist before the pipeline begins, and it need not end with "_targets", but it must be writeable. For optimal performance, choose a storage location with fast read/write access. If the argument NULL, the setting is not modified. Use tar_config_unset() to delete a setting.

shortcut

logical of length 1, default shortcut argument to tar_make() and related functions. If the argument NULL, the setting is not modified. Use tar_config_unset() to delete a setting.

script

Character of length 1, path to the target script file that defines the pipeline (_targets.R by default). This path should be either an absolute path or a path relative to the project root where you will call tar_make() and other functions. When tar_make() and friends run the script from the current working directory. If the argument NULL, the setting is not modified. Use tar_config_unset() to delete a setting.

workers

Positive numeric of length 1, workers argument of tar_make_clustermq() and related functions that run the pipeline with parallel computing among targets. If the argument NULL, the setting is not modified. Use tar_config_unset() to delete a setting.

config

Character of length 1, file path of the YAML configuration file with targets project settings. The config argument specifies which YAML configuration file that tar_config_get() reads from or tar_config_set() writes to in a single function call. It does not globally change which configuration file is used in subsequent function calls. The default file path of the YAML file is always _targets.yaml unless you set another default path using the TAR_CONFIG environment variable, e.g. Sys.setenv(TAR_CONFIG = "custom.yaml"). This also has the effect of temporarily modifying the default arguments to other functions such as tar_make() because the default arguments to those functions are controlled by tar_config_get().

project

Character of length 1, name of the current targets project. Thanks to the config R package, targets YAML configuration files can store multiple sets of configuration settings, with each set corresponding to its own project. The project argument allows you to set or get a configuration setting for a specific project for a given call to tar_config_set() or tar_config_get(). The default project is always called "main" unless you set another default project using the TAR_PROJECT environment variable, e.g. Sys.setenv(tar_project = "custom"). This also has the effect of temporarily modifying the default arguments to other functions such as tar_make() because the default arguments to those functions are controlled by tar_config_get().

Value

NULL (invisibly)

Configuration

For several key functions like tar_make(), the default values of arguments are controlled though tar_config_get(). tar_config_get() retrieves data from an optional YAML configuration file. You can control the settings in the YAML file programmatically with tar_config_set(). The default file path of this YAML file is _targets.yaml, and you can set another path globally using the TAR_CONFIG environment variable. The YAML file can store configuration settings for multiple projects, and you can globally set the default project with the TAR_PROJECT environment variable. The structure of the YAML file follows rules similar to the config R package, e.g. projects can inherit settings from one another using the inherits field. Exceptions include:

  1. There is no requirement to have a configuration named "default".

  2. Other projects do not inherit from the default project` automatically.

  3. Not all fields need values because targets already has defaults.

targets does not actually invoke the config package. The implementation in targets was written from scratch without viewing or copying any part of the source code of config.

See also

Other configuration: tar_config_get(), tar_config_unset(), tar_envvars(), tar_option_get(), tar_option_reset(), tar_option_set()

Examples

if (identical(Sys.getenv("TAR_EXAMPLES"), "true")) {
tar_dir({ # tar_dir() runs code from a temporary directory.
tar_script(list(tar_target(x, 1 + 1)))
tar_config_get("store") # NULL (data store defaults to "_targets/")
store_path <- tempfile()
tar_config_set(store = store_path)
tar_config_get("store") # Shows a temp file.
tar_make() # Writes to the custom data store identified in _targets.yaml.
tar_read(x) # tar_read() knows about _targets.yaml too.
file.exists("_targets") # FALSE
file.exists(store_path) # TRUE
})
}