targets (version 1.7.1)

tar_renv: Set up package dependencies for compatibility with renv

Description

Write package dependencies to a script file (by default, named _targets_packages.R in the root project directory). Each package is written to a separate line as a standard library() call (e.g. library(package)) so renv can identify them automatically.

Usage

tar_renv(
  extras = c("bslib", "crew", "gt", "markdown", "pingr", "rstudioapi", "shiny",
    "shinybusy", "shinyWidgets", "visNetwork"),
  path = "_targets_packages.R",
  callr_function = callr::r,
  callr_arguments = targets::tar_callr_args_default(callr_function),
  envir = parent.frame(),
  script = targets::tar_config_get("script")
)

Value

Nothing, invisibly.

Arguments

extras

Character vector of additional packages to declare as project dependencies.

path

Character of length 1, path to the script file to populate with library() calls.

callr_function

A function from callr to start a fresh clean R process to do the work. Set to NULL to run in the current session instead of an external process (but restart your R session just before you do in order to clear debris out of the global environment). callr_function needs to be NULL for interactive debugging, e.g. tar_option_set(debug = "your_target"). However, callr_function should not be NULL for serious reproducible work.

callr_arguments

A list of arguments to callr_function.

envir

An environment, where to run the target R script (default: _targets.R) if callr_function is NULL. Ignored if callr_function is anything other than NULL. callr_function should only be NULL for debugging and testing purposes, not for serious runs of a pipeline, etc.

The envir argument of tar_make() and related functions always overrides the current value of tar_option_get("envir") in the current R session just before running the target script file, so whenever you need to set an alternative envir, you should always set it with tar_option_set() from within the target script file. In other words, if you call tar_option_set(envir = envir1) in an interactive session and then tar_make(envir = envir2, callr_function = NULL), then envir2 will be used.

script

Character of length 1, path to the target script file. Defaults to tar_config_get("script"), which in turn defaults to _targets.R. When you set this argument, the value of tar_config_get("script") is temporarily changed for the current function call. See tar_script(), tar_config_get(), and tar_config_set() for details about the target script file and how to set it persistently for a project.

Performance

If you use renv, then overhead from project initialization could slow down tar_make() and friends. If you experience slowness, please make sure your renv library is on a fast file system. (For example, slow network drives can severely reduce performance.) In addition, you can disable the slowest renv initialization checks. After confirming at https://rstudio.github.io/renv/reference/config.html that you can safely disable these checks, you can write lines RENV_CONFIG_RSPM_ENABLED=false, RENV_CONFIG_SANDBOX_ENABLED=false, and RENV_CONFIG_SYNCHRONIZED_CHECK=false in your user-level .Renviron file. If you disable the synchronization check, remember to call renv::status() periodically to check the health of your renv project library.

Details

This function gets called for its side-effect, which writes package dependencies to a script for compatibility with renv. The generated file should not be edited by hand and will be overwritten each time tar_renv() is called.

The behavior of renv is to create and manage a project-local R library and keep a record of project dependencies in a file called renv.lock. To identify dependencies, renv crawls through code to find packages explicitly mentioned using library(), require(), or ::. However, targets manages packages in a way that hides dependencies from renv. tar_renv() finds package dependencies that would be otherwise hidden to renv because they are declared using the targets API. Thus, calling tar_renv this is only necessary if using tar_option_set() or tar_target() to use specialized storage formats or manage packages.

With the script written by tar_renv(), renv is able to crawl the file to identify package dependencies (with renv::dependencies()). tar_renv() only serves to make your targets project compatible with renv, it is still the users responsibility to call renv::init() and renv::snapshot() directly to initialize and manage a project-local R library. This allows your targets pipeline to have its own self-contained R library separate from your standard R library. See https://rstudio.github.io/renv/index.html for more information.

See Also

https://rstudio.github.io/renv/articles/renv.html

Other scripts: tar_edit(), tar_github_actions(), tar_helper(), tar_helper_raw(), tar_script()

Examples

tar_dir({ # tar_dir() runs code from a temp dir for CRAN.
  tar_script({
    tar_option_set(packages = c("tibble", "qs"))
    list()
  }, ask = FALSE)
  tar_renv()
  writeLines(readLines("_targets_packages.R"))
})
tar_option_reset()